From pv magazine Global

Researchers led by scientists from Mohammed First University in Morocco explored the use of solar panels equipped with an anti-reflective coating at Green Energy Park, a Benguerir-based test facility located at a site that has favorable solar irradiance reaching 2,239 kWh/m2/year but a harsh climate, with high temperatures, low precipitation, and high level of aerosols.

The experiment involved setting up two commercial modules side-by-side, one with an anti-reflective (AR) coating and the other without.

“It is the first study to comprehensively assess the electrical, optical, durability, and economic aspects of AR coatings simultaneously and under real, harsh outdoor conditions,” Ahmed Alami Merrouni, corresponding author of the research, told pv magazine, adding that the “unexpected yet significant result” was the “considerable reduction” of 2.7% for the levelized cost of energy (LCOE).

The scientists assessed the electrical performance of the AR-coated PV modules over a 10-month period, carrying out frequent cleaning, and weekly transmittance measurements. Using the results from the field study, the team calculated the effect AR-coated modules would have on financial performance in a large-scale PV plant, using a 40 MW PV power plant as a case study.

“The simulation results unveil that a 40 MW power plant employing standard PV panels yields an annual electricity output of 69 GWh. In contrast, an analogous power plant incorporating ARC-coated panels attains an elevated electricity generation of 72 GWh, signifying a notable 5.5 % enhancement in comparison to conventional panels,” stated the researchers.

“From an economic standpoint, the simulation outcomes reveal an LCOE of 0.037€/kWh for the 40 MWe power plant utilizing non-coated PV modules. Conversely, the LCOE for the same power plant employing ARC modules amounts to 0.0368 €/kWh, showcasing a 2.7 % decrease in electricity production costs,” they added.

Laboratory abrasion tests on AR-coated glass samples were also conducted to determine the impact on optical performance and coating durability.

“Our study found that after 1,500 abrasion cycles, which simulate 29 years of weekly cleaning, the optical properties only decreased by 2.6%. This impressive durability opens the possibility of using dry cleaning methods for PV power plants with this coating, significantly reducing cleaning costs and conserving water,” said Alami Merrouni.

The AR-coated glass samples also demonstrated “good optical performance against soiling”, with soiling losses lower by 3.7 % compared to non-coated samples for the same exposure period, according to the scientists.

Since carrying out the study, feedback from other researchers in the field of solar energy and Moroccan governmental organizations has been positive, according to Alami Merrouni.  “The most highlighted and significant result that attracts attention is the durability of the AR coatings under linear abrasion tests,” he said.

“This feedback underscores the practical benefits and potential for the wide adoption of AR coating solutions, especially in regions like Morocco where, in addition to its high performances, the AR coating may open the possibility of using dry cleaning methods enabling a significant reduction on the cleaning costs and water saving, which is crucial for desert locations,” he concluded.

The research is detailed in the paper “Experimental analysis of Anti-Reflective coating performance in desert Climate: Yield analysis, soiling impact and cleaning durability evaluation,” published in Sustainable energy technologies and assessments.

Scientists from Colorado State University have conducted field research on vegetable crop growth located below PV modules with varying transparency. The vegetables are grown under thin film, semi-transparent cadmium telluride (St-CdTe) modules with a transparency of 40%, bifacial monocrystalline silicon (BF-Si) modules with a transparency of 5%, and opaque polycrystalline silicon (O-Si) modules with a transparency of 0%.

“Semi-transparent PV (STPV) module technology has emerged as a potential solution to mitigate the negative effects of dense shade in cropping systems while maintaining a high module density,” said the academics. “To our knowledge, this is the first replicated research experiment that evaluates module transparency types in an irrigated vegetable field setting.”

The experiment was conducted over two growing seasons, 2020 and 2021. The study site was located in Fort Collins, Colorado, USA, in a field designated for research. Overall, the growth of six vegetables was tested: jalapeño pepper, bell pepper, lettuce, summer squash, Tasmanian chocolate tomatoes, and red racer tomatoes.

“There were three planted rows across the entire site – north, middle, and south,” explained the group. “Lettuce, peppers, and tomatoes were planted in two offset sub-rows in 0.9 m beds covered with black plastic mulch in the north and south rows. Squash was exclusively planted in the middle row both years with 1.2 m spacing on center.”

As for the PV modules, the scientists used three of each type. They were installed in a set position of 35 degrees facing south, with the bottom edge of the modules 1,220 mm above the ground and the back at a height of 2,360 mm. The ST-CdTe modules had a rated output of 57 W, the BF-Si had 360 W, and the O-Si had 325 W.

“Each of the 12 crop subplots, including both PV arrays and control plots, spanned a width of 4.3 m, with a 4.3 m spacing between adjacent subplots,” the researchers said. “Due to the single pole mount configuration, the shadow cast from the modules moved throughout the day. With this, the crops received direct sun early and late in the day, with maximum shade during the peak hours of the day and immediately under the modules.”

Per the results, the summer squash under all three module types displayed significantly lower yields than the control plot, regardless of the module transparency type. While in the control plot, under full sun conditions, the squash yielded 5.1 kg per plant, it grew 3.2 kg in the BF-Si scenario, 3.2 kg in the O-Si scenario, and 4.1 kg in the ST- CdTe scenario.

The other vegetables had equal or higher average yields to the control under the 40% transparent ST-CdTe treatment but with no statistically significant differences. The jalapeño peppers yielded 155 g per plant in full sun, 161 g in the BF-Si, 155 g in the O-Si, and 162 g in the ST- CdTe, while the bell pepper yielded 295 g per plant in full sun, 294 g in the BF-Si, 278 g in the O-Si, and 346 g in the ST- CdTe.

The lettuce weight per head was 105 g in full sun, 126 g in the BF-Si, 111 g in the O-Si, and 129 g in the ST- CdTe. The Tasmanian chocolate tomatoes had an average of 926 g per plant in full sun, 1,060 g in the BFSi, 1,069 g in the O-Si, and 1,278 g in the ST- CdTe. Lastly, the red racer tomatoes had 867 g per plant in full sun, 733 g in the BF-Si, 903 g in the O-Si, and 962 g in the ST- CdTe.

“The optimization of the agri-PV array with semi-transparent PV modules could increase agricultural production while maintaining the added protection of an energized canopy in traditional APV systems,” the researchers concluded. “More research is needed to better understand the economic tradeoffs between increased module transparency compared to vegetable crop production, while also considering the increased energy yield from module bifaciality.”

Their findings were presented in “Vegetable Crop Growth Under Photovoltaic (PV) Modules of Varying Transparencies,” published in Heliyon.

People on the move: Mayfield Renewables, First Solar, Meteomatics Job moves in solar, storage, cleantech, utilities and energy transition finance.

Net metering hangs in the balance in New Hampshire A group of interested parties, including the state’s utilities and the Granite State Hydropower Association, agreed on a settlement that calls for the rate to stay the same for two years.

Northvolt closes Cuberg’s ops, shifts lithium-metal battery R&D to Sweden Three years after acquiring U.S.-based Cuberg, Swedish battery maker Northvolt has decided to shut down the California unit and move future lithium-metal battery R&D to Sweden.

PV module cooling tech based on single-channel containing nanofluids Scientists in Mexico have conceived a new solar module cooling tech that can reportedly improve PV power generation by up to 2%. The system uses nanofluids embedded in an aluminum single-channel attached to the back of the panel.

GM signs agreement to match assembly plant power demand with solar The automaker entered a 15-year, 180 MW solar power purchase agreement (PPA).

From pv magazine Global

Student solar car teams from Canada’s Polytechnique Montréal and École de technologie supérieure made it to the podium at the Electrek American Solar Challenge 2024, a distance-based competition for solar cars.

With a multiple occupant vehicle (MOV) named Esteban 11, students from Polytechnique Montréal won first place in the MOV category in both the qualifier circuit race, known as the Electrek Formula Sun Grand Prix (FSGP) and in the main race, the Electrek American Solar Challenge, which requires completing a minimum of 1,500 miles (2,400 km).

The Esteban team completed 1,610.3 miles at an average speed of 36.2 mph (58.26 km/h), with an overall score of 73.86. The MOV category is scored on factors beyond the distance covered, such as practicality, amount of external energy used, and whether the 35 mph target average speed was maintained.

The other Montreal team, hailing from École de technologie supérieure, won silver in the single occupant vehicle (SOV) category, completing 2,004.5 miles with the Éclipse XI solar car. The SOV class is scored solely on miles driven. Only in the event of a tie is elapsed time relevant.

This year’s winner of the SOV class was the University of Michigan student team with its Astrum solar car, completing 2,095.5 miles (3,372 km) with an average speed of 37.51 mph.

Esteban 11 by the Polytechnique Montréal student team

The Esteban project spokesperson told pv magazine that the team began competing with a two-seater MOV in 2019. “Switching categories allowed us for more creativity in our design. Being multiple occupants also displays the efficiency of our car. Especially in the event, the broader public gets to learn how the technology evolves,” said the Esteban spokesperson.

The team used a 1218 W solar array with cells from Singapore-based Maxeon and encapsulation by German specialist PV panel manufacturer OPES Solutions. The 4-wheel vehicle weighed 293 kg, measuring 4.92m x 1.8m x 1.04 m. The battery was a 9.2 kWh by China-based BAK Technologies, weighing 47 kg, paired with two 5kW M2096D-3 hub motors from Japan’s Mitsuba in a carbon fiber monocoque.

“One great challenge we had was splitting the battery pack. This allowed us to have a lower center of gravity but complicated the monitoring and protection,” the spokesperson said, adding that a new printed circuit board design adhering to professional standards with features to manage heat effects also made a difference this year.

Éclipse XI by the École de technologie supérieure student team

The Éclipse XI, a 3-wheel design weighing 200 kg, measured 4.5 m x 1.5 m x 1.1 m. It was equipped with a 1000 W solar array spanning 4m2, based on Sunpower Maxeon Gen 3 solar cells. It had a 20 kg 5kWh lithium ion battery by Japanese manufacturer Panasonic.

The Éclipse XI team not only won a silver medal in the American Solar Challenge competition, it also won two awards, an Electrical Design Award, and the Abe Poot Award. The latter is named after an influential figure in the U.S. solar car racing community, that recognizes team spirit of collaboration and cooperation, according to the Éclipse XI team spokesperson.

The Electrical Design Award recognized the performance of the electrical setup. “At FSGP, we were the first team to complete both electrical and battery protection system inspection with all green status. We also proved that our electrical systems were robust and reliable along both races, more than 4500 km without any issue,” the Éclipse team spokesperson told pv magazine.

“For this race, we used a custom-made motor casing with air cooling system to help us climb the most steeped hills along the route,” they said, adding that the team is currently working on an improved maximum power point tracking that will “maximize efficiency across all operating ranges” to be able to reduce overall weight and cost.

The Electrek American Solar Challenge 2024 attracted over 30 student-run teams from the U.S. and Canada. It began on 20 July in Nashville, Tennessee, and ended in Casper, Wyoming, on 27 July. The primary route has 1562.2 total miles to complete and vehicles must average at least 35 mph for the event. There are seven optional loops to earn additional points.

Researchers at the U.S. Department of Energy’s National Renewable Energy Laboratory (NREL) used a circular economy framework to determine how to scale, deploy, and design future metal halide perovskite solar panels to be easily recyclable.

As initiatives to commercialize metal halide perovskite (MHP) solar technology are underway, especially efforts to ensure durable performance in the field, NREL researchers initiated a study of sustainability design factors as another important aspect of commercialization.

“Our goal with this perspective paper was to point out that existing technology does not prioritize building products with sustainability and circularity up front. It was not developed specifically to minimize waste or use the lowest energy processing steps,” Joey Luther, the research’s corresponding author, told pv magazine. “However, since PV is inherently a sustainable technology, now is the time to begin to evaluate how we can develop the commercialization of MHPs with sustainability in mind.”

The group performed the evaluation based on a a prototypical single-junction MHP module close to commercial designs, framed with mounting rails in a glass-glass module configuration with polymer encapsulants, and edge sealing typical of silicon and cadmium telluride panels. The individual PV cells are integrated via scribing, and include front glass coated with a transparent conductor, the MHP layer sandwiched between electron and hole transport materials and a back electrode.

In addition, the team drilled down into constituent chemicals, molecules, and materials typically used in perovskite A, B, and X sites.

For all of the above, sustainability aspects were evaluated, such as energy intensity of manufacturing, carbon intensity, rare mineral mining, recyclability, earth abundance, cost, fossil fuel derived, fail-safe encapsulation, health hazards, and flammability among others.

The prototype was further evaluated based on critical material concerns, embodied energy, carbon impacts and circular supply chain processes. The analysis included the frame, rail materials, front and back glass, encapsulation polymers, solvents, electron and hole transport materials, and electrode materials.

In an information-rich table, the team detailed how the eleven “Rs” of circularity for photovoltaics can offer opportunities and advantages within sustainable manufacturing. An adaptation of the “reduce, reuse, recycle” concept, some of the Rs discussed are listed here: refuse fossil fuels and carbon-intensive materials; reduce energy, material, and carbon input, repair or design for repair, reuse, repower, restore, and recover energy.

When it comes to recycling, the researchers noted that ‘recycling’ includes both downcycling to lower-value, or lower-quality, products. They explained that recycling is beneficial when recovered feedstocks replace virgin materials, which require energy-intensive refining. There is room for improvement. For example, PV glass manufacturing is still using virgin sources in new PV glass products and not post-consumer PV glass cullet, they noted.

The team identified five key areas and opportunities to pursue. The first is enhancing MHP module reliability to meet current commercial PV lifetime standards. Second, investigate the supply chain of low-trade-volume raw materials, such as cesium, and ensure adequate accessibility for the sustainable scale-up of a given MHP composition, or focus research, to reduce or substitute. Third, seek alternatives to indium. Fourth, explore how to accelerate PV glass recycling without downcycling. And fifth, further improve module remanufacturing processes.

“A reasonable combination of these solutions would enable MHP-PVs to contribute meaningfully and sustainably to the energy transition,” stressed the team.

The scientists asserted that “circularizing the PV supply chain, particularly through recycling and remanufacturing glass”, provides opportunities to lower the embodied energy and carbon of MHP-PVs. “Improvements in lifetime and reliability remain paramount for the energy transition and provide the largest benefits,” they concluded.

The perspective is detailed in “Sustainability pathways for perovskite photovoltaics,” published by nature materials.

From ESS-news.com

The U.S. Department of Energy (DOE) announced the opening of the Grid Storage Launchpad (GSL), a new facility at the Pacific Northwest National Laboratory (PNNL) in Richland, Washington.

The 93,000-square-foot or nearly hectare-sized research facility will house 30 laboratories and about 100 researchers. It is equipped to evaluate new battery materials and battery systems up to 100 kW operating under realistic grid conditions.

The DOE hopes that the ability to collaborate with scientists, engineers, industry, and agencies in one building will accelerate the development and roll-out of new grid-scale storage energy technologies and ideas.

Along with research initiatives, GSL will serve as an educational center, training technicians, grid operators, first responders, safety officials, and more.

Vince Sprenkle, energy storage expert and GSL’s first director said: “Energy storage will be a significant part of a resilient and reliable grid that’s fully decarbonized. And GSL will help us get there,” said “GSL is truly an integrated facility that incorporates everything from fundamental materials research to testing 100-kilowatt batteries.”

Read the rest of the article on ESS-news.com.

From pv magazine Global

A research team has determined that covering the world’s highways with solar roofs could generate 17,578 TWh per year, which is more than 60% of global electricity consumption in 2023.

Their study, titled “Roofing Highways With Solar Panels Substantially Reduces Carbon Emissions and Traffic Losses,” was recently published in the journal Earth’s Future. It explores the potential to install solar panels above highways and major roads.

With more than 3.2 million km of highways worldwide, the researchers calculated the costs and benefits of constructing a solar panel network using polycrystalline solar panels with a 250 W capacity. The analysis found that covering highways with solar panels could generate more than four times the annual energy output of the United States and offset 28.78% of current CO2 emissions, while also reducing global traffic deaths by 10.8%.

“This really surprised me,” said Ling Yao, a remote sensing scientist at the Chinese Academy of Sciences and the study’s lead author. “I didn’t realize that highways alone could support the deployment of such large photovoltaic installations, generating more than half of the world’s electricity demand, and greatly easing the pressure to reduce global carbon emissions.”

The researchers also identified regions such as eastern China, Western Europe, and the US East Coast as the most ideal for deployment, despite challenges related to setup and maintenance costs. Yao noted the importance of pilot programs to demonstrate the practicality of this concept.

The research team consisted of academics from the Chinese Academy of Sciences, Tsinghua University and Chinese Academy of Geosciences, all located in Beijing, as well as New York’s Columbia University.

From pv magazine Global

A research group led by scientists from Purdue University has created a novel model for assessing the growth of corn in agrivoltaic facilities and has proposed to use a spatiotemporal shadow distribution (SSD) model to optimize crop yield and power production.

The new method is based on the agricultural production systems simulator (APSIM) plant model, which is based on finer temporal resolution, with literature reportedly supporting its validity. The SSD model, which accounts for the shadow cast by the PV panels, was used in conjunction with the National Renewable Energy Laboratory (NREL) radiation data. These combined data were then calibrated and validated with the results from their field measurements.

The field experiment was conducted at an agrivoltaic farm at Purdue University in West Lafayette, Indiana, USA. There, PV panels were deployed in two arrangements, either 300 W modules placed adjacent to each other or 100 W modules arranged in an alternate checkerboard pattern. They all used single-axis trackers and are 6.1 meters high. The set-up was tested between April and October of 2020.

“For validation, 12 plots are considered,” the academics said. “Corn ears of three representative plants from each of these plots were hand-collected. Overall, 570 corn plants from the without-PV region and 36 corn plants from the with-PV region, respectively, were used in the analysis. The ears were cleaned, imaged, and processed using a DuPont pioneer ear photometer.”

The field measurement showed that the corn yield from the area without PV was measured to be 10,955 kg/ha, compared with the yield of 10,182 kg/ha of the PV area. That was in reported agreement with the novel model, which predicted 10,856 kg/ha for the no-PV area and 10,102 kg/ha for the agri-PV field.

The researchers then used the model to test the impact of the tracker height, distance between arrays, panel angle, and the activation of the tracking system on yield. They first found that designs that lower the tracker height without impeding the movement of plant machinery should be envisioned as the overall average corn yield is a weak function of the tracker height up to 2.44 m.

“However, the variability from one corn row to another increases as the tracker height is reduced,” they further explained. “Another interesting finding is that for our PV module sizes, increasing the distance between the adjacent PV rows beyond 9.1 m, while keeping the total power over the entire land constant, does not lead to an increase in corn yield based on the total land area.”

They also found that anti-tracking (AT) around solar noon provided the most significant increase in the corn yield. “However, this increase in corn yield of 5.6% is quite modest and should be weighed against a substantial decline in solar power,” the group emphasized.

The proposed model was presented in “Optimizing corn agrivoltaic farming through farm-scale experimentation and modeling,” published in Cell Reports Sustainability. The research group also included academics from Denmark’s Aarhus University.

From pv magazine Global

Researchers at the University of Texas in Austin have explored the formation of polarons by examining the properties of halide perovskites.

Halide perovskites are used in applications such as photovoltaics due to their optoelectric properties. In the research paper “Topological polarons in halide pervoskites,” published in the Proceedings of the National Academy of Sciences, the scientists used supercomputers Lonestar6 and Frontera from the Texas Advanced Computing Center (TACC) to analyze these properties at the individual atom level.

The team developed EPW, an open-source Fortran and message-passing interface code that calculates properties related to electron-phonon interaction. The EPW code specializes in studying how electrons interact with vibrations in the lattice of a solid, which causes the formation of polarons.

“We found that electrons form localized, narrow wave packets, which are known as polarons,” Feliciano Giustino, one of the paper’s lead authors, told TACC. “These ‘lumps of charge’ – the quasiparticle polarons – endow perovskites with peculiar properties.”

“These polarons show very intriguing patterns. The atoms rotate around the electron and form vortices that had never been observed before. We suspect that this strange vortex structure prevents the electron from going back to the unexcited energy level,” Giustino explained. “This vortex is a protected topological structure in the halide perovskite lattice material that remains in place for a long time and allows the electrons to flow without losing energy.”

In the research paper, the scientists add that polarons take many different forms in halide perovskites, including small polarons, large polarons and charge density waves.

“We find that these emergent quasiparticles support topologically nontrivial phonon fields with quantized topological charge, making them nonmagnetic analog of the helical Bloch points found in magnetic skyrmion lattices,” the researchers said. “Our findings suggest that halide perovskites may be regarded as a class of quantum materials where electron-phonon couplings replace the traditional electron–electron interactions of correlated electron systems.”

NASA installed the solar array for the Europa Clipper spacecraft, a robotic craft with a mission to reach Jupiter’s moon Europa by 2030. The large moon is one of 95 that orbit Jupiter, and it is studied closely due to its potential to host life in its global liquid ocean underneath its icy surface. 

Europa Clipper will be the largest spacecraft NASA has ever developed for a planetary mission. The craft is outfitted with large solar arrays that will serve as the primary power source for the mission. The arrays are large, as the Jupiter system is more than five times as far from the sun as Earth. 

The craft’s arrays are built as two five-panel wings. Each solar array measures 46.5 feet in length. To install the array, the team suspended the solar array on a gravity offload support system that helps support the weight of the solar array while it’s here on Earth. Next, NASA technicians will begin inspecting and cleaning as part of its assembly, test and launch operations. 

The array uses Azur Space 3G28 solar cells – with substrate panels from Airborne in the Netherlands, laid down by Leonardo in Italy and integrated into solar panels by Airbus Defence and Space in the Netherlands. The NASA Juice Mission also uses Azur Space 3G28 cells. 

The solar cells are designed for space travel, with self-annealing properties and the ability to operate under the intense radiation of space. More details can be found on an Airbus document.

The array is folded when launched and is designed for a passive deployment with spring-motorized hinges.

At launch, Europa Clipper will weigh approximately 13,000 lbs. Almost half of the weight will be fuel – nearly 6,000 lbs of propellant.

“Europa Clipper will launch in October 2024 on a SpaceX Falcon Heavy rocket from Kennedy Space Center in Florida. The spacecraft will fly by Mars, then back by Earth, using the gravity of each planet to increase its momentum. These so-called ‘gravity assists’ will provide Europa Clipper with the velocity needed to reach Jupiter in 2030,” said NASA.

From pv magazine Global

PeroNova, a U.S.-based startup specializing in solar perovskite technologies, has developed a solar perovskite module for building-integrated photovoltaics (BIPV) and space applications.

“Our novel interfacial treatment technology enhances the stability and reliability of perovskite films in tests, and in fabrication conditions. Thermal cycling resistivity tests demonstrated over 80% of initial power conversion efficiency after 2,500 cycles,” a PeroNova spokesperson told pv magazine.

The company currently develops lab-scale four-terminal (4T) perovskite-silicon tandem solar cells and 900 cm2 mini perovskite modules. The lab-scale cells have reportedly an efficiency of around 30%, while the modules achieve around 28% for the 4-T tandem configuration, 22% for outdoor applications, and 18% for space.

Founded in 2023,  PeroNova plans to address the demand for solar power in portable electronics, space and rooftop markets. “Our team has diligently worked to create a best-in-class American-made product that offers affordable and reliable renewable energy globally,” said co-founder and CEO, Min Chen, in a statement.

The company also recently announced it is collaborating with unspecified U.S. real estate developers intending to “bring large-scale implementation” of BIPV and agrivoltaics across the country. It will also be working with undisclosed space tech companies.

PeroNova has secured five patents from the U.S. Department of Energy. It also recently appointed Peter H. Diamandis, a U.S.-based entrepreneurial investor and founder of the XPRIZE Foundation, to its advisory board where he will “advise on product design, commercialization strategy and investor relations.”

From pv magazine Germany

The Dutch research institute TNO has carried out a detailed life cycle analysis of floating PV systems on behalf of the International Energy Agency’s (IEA) Photovoltaic Power Systems Programme (PVPS). It shows that the floating systems have a slightly larger carbon footprint than land-based systems, mainly due to the additional components for the floating structure.

According to the experts, the carbon footprint of floating systems is around 15% larger than that of land-based systems with an east-west orientation. Compared to those with a south orientation, it is around 25%. However, floating systems have other advantages, such as the use of water instead of land and potential synergies with hydroelectric power plants.

According to their calculations, the CO2 emissions of floating systems are around 50 grams per kilowatt-hour of electricity generated, around seven times less than the current electricity mix in Germany and three to four times less than the EU-wide target for 2030.

For their analysis, the experts compared two real floating systems, one in Germany with a support structure made of high-density polyethylene (HDPE), and one in the Netherlands with a structure made of steel and HDPE, with hypothetical systems on land.

Recycling further reduces the carbon footprint

According to the experts, the carbon footprint of the floating system could be reduced with three measures: by using electricity from low-emission sources in the manufacture of the PV modules, by using recycled materials in the support structures and by recycling the HDPE at the end of its life cycle.

“Our study of two operating systems in Western Europe shows that floating photovoltaic systems on small inland waters can be a good complement to ground-mounted systems from the point of view of greenhouse gas emissions over the entire life cycle,” said Josco Kester, co-author of the study.

The researchers recommend further research into the environmental impact of floating photovoltaic systems, particularly with regard to the impact on aquatic ecosystems.

Researchers at the Massachusetts Institute of Technology (MIT) have achieved a significant breakthrough in stabilizing a key component of perovskite solar cells. They have developed a method to synthesize Spiro-MeOTAD, a crucial material for charge transport, without using noble metals. This development led to the creation of a solar cell with an impressive 24.2% efficiency, although it experienced rapid degradation.

The research, led by Dr. Matthias J. Grotevent and Nobel Prize laureate Moungi G. Bawendi, demonstrated that their new method can produce a Spiro-MeOTAD material that remains stable even after 1,400 hours of testing at elevated temperatures (85°C) under continuous one-sun illumination. This durability is critical for materials exposed to the high temperatures and humidity typical of solar panel environments.

Their study, titled “Additive-free oxidized Spiro-MeOTAD hole transport layer significantly improves thermal solar cell stability,” underscores the potential of this new method. The researchers discovered that “even at low doping concentrations of 1%,” Spiro units could increase their electrical conductivity by orders of magnitude.

One of the key benefits of the material blend is its high glass transition temperature, which is above 115°C. This allows the solar cell to exhibit enhanced thermal properties, making it more suitable for use in high-temperature environments.

In all of this, the research team says that while the thermally stable Spiro unit is only in a solar cell that reaches 6% efficiency, they see a path via future research to stabilize the 24% efficiency solar cell.

According to the study, Spiro is currently an expensive material, priced online at $334 per gram. However, the researchers predict that the price could drop significantly with bulk orders reaching kilogram levels, potentially falling to $30 per gram or even $3/gram. When asked about the material’s cost by pv magazine USA, Dr. Grotevent estimated that a full-sized solar panel would require approximately 0.33 grams of Spiro, assuming a layer thickness of about 120 nanometers. This would result in a material cost of less than $0.003 per watt for a solar panel with an efficiency of over 20%, adding about $1.06 to the overall cost of the module.

Researchers are exploring three main approaches to deploying perovskites, which have so far seen limited use. The first method involves stacking perovskites atop silicon within the solar cell, a technique that has gained significant attention for its high efficiency, exemplified by Longi’s record-setting 34.6% perovskite-silicon tandem solar cell. The second approach, currently undergoing testing by GCL Perovskites, involves constructing nearly complete perovskite solar panels and layering them over similarly complete silicon solar panels to combine their outputs. The third approach features standalone perovskite panels without silicon, as demonstrated by the 1 MW China Three Gorges solar power facility.

From pv magazine Global

Researchers at the Universiti Teknikal Malaysia Melaka have outlined a techno-economic optimization approach to define the appropriate power sizing ratio (PSR) for inverters used in grid-connected PV systems.

The PSR is the ratio of the inverter’s rated power to the total rated power of the connected PV modules and is crucial to maximizing energy yield and income. “An undersized inverter limits the system’s ability to convert all the generated DC power to AC power, leading to potential energy losses,” the scientists explained. “Conversely, an oversized inverter incurs higher initial costs without a proportional increase in energy production.”

The proposed methodology uses a pattern search algorithm (PSA), which is an optimization technique commonly utilized for problems with complex relationships and potentially noisy data, to ensure an accurate representation of real-world inverter behavior.

The model considers radiation, convection thermal representations, and real-world weather data. It also takes into account data from the inverters’ datasheets to evaluate the efficiency curve of the devices. From this curve, it then extracts key points to identify efficiency values between the chosen data points.

“The model undergoes a calibration phase where the efficiency curve points are iteratively adjusted by the PSA until the estimated/modeled values closely match the actual measurements obtained from the real system over a predefined period,” the group explained. “This calibration step guarantees that the model accurately reflects the real-world performance of the system.”

According to the scientists, the model can estimate the annual power yield of a solar array for each iteration step through various DC/AC power ratios, which in turn allows PV system owners to find the optimized ratio that maximizes energy production.

They also warned that the proper selection of the optimal PSR needs to be complemented by economic considerations relating to inverter costs, operation and maintenance, inverter complexity, and monitoring systems. “It’s important to note that the cost function doesn’t directly represent monetary value but rather a relative measure of economic performance,” they stressed. “The actual economic feasibility would depend on specific system costs and electricity prices.”

The novel methodology was presented in the study “Techno-economic optimization of photovoltaic (PV)-inverter power sizing ratio for grid-connected PV systems,” published in Results in Engineering.

“Future research directions involve exploring the integration of additional factors into the model,” the research team concluded. “These factors could include advanced weather forecasting capabilities, dynamic pricing schemes, and potential application to different types of PV systems or even broader renewable energy systems.”

From pv magazine Global

An international research team has outlined a new design for solar cells based on antimony trisulfide (Sb₂S₃) that can reportedly result in 30% higher efficiency compared to existing Sb₂S₃ solar cell concepts.

This kind of cell typology has, so far, been far from reaching commercial production, due to the low crystallinity and high resistivity of the Sb₂S₃ film, which affects the device’s performance in terms of efficiency. Sb₂S₃, however, has a good bandgap, ranging from 1.70 to 1.90 eV, and a remarkable light absorption coefficient.

In the study “Scrutinizing transport phenomena and recombination mechanisms in thin film Sb₂S₃ solar cells,” published in scientific reports, the scientists explained that Sb₂S₃ devices can achieve an efficiency of up to 26% under the radiative limit, but defects in the absorber material commonly decrease it to around 8%.

“The novelty of this work lies in its detailed theoretical examination of Sb₂S₃ solar cells, specifically focusing on the intricate interplay of various transport mechanisms such as tunneling-enhanced recombination, Sb₂S₃/CdS interface recombination, and non-radiative recombination,” they added.

Their analysis showed that two of the key factors influencing Sb₂S₃ cell performance are cadmium sulfide (CdS) layer doping and thickness, which have an impact on the device’s open-circuit voltage and short-circuit current. Furthermore, they found that bandgap and electron affinity have an influence on light absorption and charge transfer, respectively.

They also explained that fine-tuning the CdS layer with a high bandgap allows a greater number of photons to effectively penetrate the absorber. “Simultaneously, a lower electron affinity plays a crucial role in improving key parameters like short-circuit current and open-circuit voltage, ultimately boosting the overall conversion efficiency of the solar cell,” they emphasized. “This enhancement stems from the establishment of an optimal band alignment at the CdS/Sb₂S₃ interface, reducing the barrier height and facilitating the smooth passage of electrons from the absorber layer to the CdS.”

The group also analyzed the effect of bulk traps located at the interface between CdS and Sb₂S₃ and found that the influence of these interfacial defects may have an impact on carriers’ minority lifetime, diffusion length, and surface recombination velocity. “Scientists can develop strategies to mitigate their adverse effects,” the academics said. “This includes engineering interface structures, optimizing material properties, and enhancing passivation techniques to minimize recombination and improve the reliability of the CdS/Sb₂S₃ interface, ultimately leading to more efficient and robust solar cell designs.”

The team outlined a simple solar cell architecture with the proposed optimized parameters. The device was based on a substrate made of glass and indium tin oxide (ITO), a CdS layer, an Sb₂S₃ absorber, and a gold (Au) metal contact.

Simulated and tested under standard illumination conditions, the device showed a power conversion efficiency of 11.68%, an open-circuit voltage of 1.16 V, a short-circuit current density of 9.5 mA cm⁻², and a fill factor of 54.7%. “Notably, the optimized Sb₂S₃ solar cell not only exhibits superior performance but also demonstrates enhanced reliability in mitigating interfacial traps at the CdS/Sb₂S₃ interface, thanks to improved band alignment control and parameter optimization,” the scientists said.

The research group comprised scientists from Algeria’s research institute Laboratory HNS-RE2SD, the Bangladesh Atomic Energy Commission, Mexico’s Universidad Autónoma de Querétaro, India’s Saveetha Institute of Medical and Technical Sciences and the Kalasalingam Academy of Research and Education, as well as the King Saud University in Saudi Arabia and the Yeungnam University in South Korea.

From pv magazine Global

A review of indoor PV cell technologies by an international research team documents over 250 large area and small area commercial and laboratory devices. It covers organic, dye-sensitized, and perovskite devices, as well as crystalline and amorphous silicon, III-V semiconductor, chalcogenide, and emerging lead-free alternative cells.

“We observed that the interest in the field was really taking off, so we believed a comprehensive review on all indoor PV technologies was due,” the review’s co-author Giulia Lucarelli told pv magazine.

The review also includes a discussion about applications, recent progress, and strategies used to design more stable, highly efficient cells that operate at very low light levels.

“We have provided the performance details of the indoor PV devices at 200 lx and 1000 lx illuminance,” corresponding author, Thomas M. Brown, told pv magazine, explaining that most homes have a 200 lx illuminance, whereas 1000 lx is typical in very well-lit environments like supermarkets.

Brown pointed out that one of the initial high-volume market niches for indoor PV has been electronic supermarket shelf labels. Other applications are emerging, such as Internet-of-Things products, where PV is seen as enabling a “fit and forget” approach, where a product is installed once with no further maintenance required. “Think of applying a temperature or other type of sensor in your home and leaving it there to operate without ever having to replace batteries,” said Brown.

Cell technologies covered in the review range from crystalline and amorphous silicon to III-V semiconductor and chalcogenide devices, as well as organic, dye-sensitized, perovskite, and lead-free alternative devices.

Looking at the power conversion efficiency (PCE) and maximum power density (MPD) the team made several observations. For example, it said that it was “obvious that irrespective of the indoor lamp type or intensity”, perovskite solar cells have “outdone” other PV technologies both in terms of efficiency and output power.

The team observed that organic photovoltaic devices (OPV) performed well under light-emitting diodes (LED), while dye-sensitized solar cells (DSSC) outperformed in fluorescent light (FL). But it also cautioned there was only a limited number of reports making it “difficult” to draw any conclusions.

“Among the established technologies, compound and thin film semiconductors in recent years have shown considerable improvement in performance, with the former delivering high efficiency and output power,” stressed the team. “The lead-free alternatives have just entered the indoor PV arena and have managed to deliver the highest efficiency of around 18 % with a tin-based perovskite.”

Standards for performance reporting were discussed, particularly the need for a protocol for measurement in standard light source spectrum and a standard illuminance level, or levels. “The most utilized currently are 200 lx and 1000 lx so both should continue to be reported,” said the scientists.

They explained that MPD reporting for 200 lx and 1000 lx illuminance is important for product developers designing energy harvesting solutions and products that operate in a range of lighting conditions. “MPD is a more immediate metric since product developers who wish to integrate PV in their items know exactly what is coming out of the PV device,” co-author Abhisek Chakraborty told pv magazine. 

Brown added that indoor lamp spectra are diverse, ranging from LED, to compact fluorescent and lamp bulbs with different color temperatures. “We only have 1 sun but a myriad of indoor light sources,” said Brown.

They also noted that whereas crystalline silicon, thin film, and new PV technologies have stability protocols for outdoor applications, and accelerated stress tests, these are “still lacking” for PV-designed indoor environments only.

In summarizing the findings, the team noted indoor laboratory efficiencies for emerging PV technologies are reaching efficiencies in the range of 35 – 45 % under 200 lx and 1000 lx. “The corresponding electrical power densities are in the range of 20 – 25 μW cm-2 at 200 lx and the range of 120 – 150 μW cm2 at 1000 lx illuminance,” it said.

There is work to do in indoor PV stability and more investigation under continuous indoor illumination, noted the team, pointing out that improvements can be achieved “through the right choice of materials, device design and scalable manufacturing” processes.

“The goal is to improve performance while increasing stability and reducing the cost of not only the indoor devices but their integration capabilities with the electronic products they aim to power,” it said.

“As mentioned earlier there is a question of different reporting, illumination, and measurement conditions for indoor PV,” Brown said, referring to the future direction of the research. “We are trying to present some best practices for this. We are also working on some national projects related to developing perovskite PV indoors via more sustainable materials and fabrication processes.”

The review appears in “Photovoltaics for Indoor Energy Harvesting,” published by Nano Energy. The researchers were from Italy’s Tor Vergata University, the Netherlands Organization for Applied Scientific Research (TNO), the Fundación Escuela Tecnologica in Colombia, and Jain University in India.

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Residential PV power forecasting method based uniquely on direct radiation Researchers in Spain have created a novel PV forecasting method that uses only direct radiation as a parameter. They found it to be “comparable, if not superior” to four established forecasting techniques. The method could help homeowners with PV systems decide when to use electricity-intensive appliances and cleaning systems.

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Amazon hits 100% renewable energy goal seven years ahead of schedule The retail giant matched 100% of the electricity used in its operations with investments in renewable energy in 2023.

All-perovskite tandem solar cell based on tin-lead perovskite achieves 27.8% efficiency Scientists in the United States have fabricated an all-perovskite tandem solar cell that reportedly shows reduced interfacial energy loss in the cell’s top device. It was built with a hole transport layer based on a compound known as P3CT that was doped with lead iodide.

From pv magazine Global

A group of researchers led by the University of Toledo in the United States have fabricated an all-perovskite tandem solar cell with a wide-band-gap top cell based on tin-lead (Pb-Sn) perovskite and a low-band-gap bottom cell relying on a conventional perovskite substrate.

“The technology readiness level (TRL) of the tandem device investigated in this study is still low at TRLs 2-3,” the research’s corresponding author, Zhaoning Song, told pv magazine. “Our work, however, proves the feasibility of enhancing the stability of all-perovskite tandem solar cells, but more work needs to be done to apply this technique to industrial production.”

The key feature of the tandem cell is the top device’s hole transport layer (HTL), which was fabricated with a Pb-doped compound known as poly[3-(4-carbox- ybutyl)thiophene-2,5-diyl] (P3CT), a material that reportedly offers excellent stability and relatively high hole mobility.

“We introduce Pb doping to increase its work function and minimize the energy level offset with the Sn-Pb perovskite,” the academics explained, noting that P3CT represents a valid alternative to commonly used PEDOT-PSS. “The Pb dopants also provide nucleation sites to enable high-quality Sn-Pb perovskite film growth.”

The group built the top cell with a substrate made of indium tin oxide (ITO), the novel HTL, the Sn-Pb perovskite absorber, an electron transport layer (ETL) based on buckminsterfullerene (C60), a bathocuproine (BCP) buffer layer, and a silver (Ag) metal contact.

The champion cell built with this architecture achieved a power conversion efficiency of 22.7%, an open-circuit voltage of 0.884 V, a short-circuit current density of 32.0 mA cm2, and a fill factor of 80.3%. It was then combined in a tandem device with an 18.7%-efficient bottom cell based on a perovskite absorber with a bandgap of 1.7 eV, an HTL made of a phosphonic acid called methyl-substituted carbazole (Me-4PACz) and an ETL relying on C60.

The champion P3CT-based tandem achieved an efficiency of 27.8, an open-circuit voltage of 2.147 (2.146) V, a short-circuit current density of 15.7 mA/cm2, and a fill factor of 82.6%.

“The P3CT-based tandems also show a higher average efficiency of 27.0% than PEDOT: PSS-based devices, proving excellent reproducibility of the high-efficiency tandems with the P3CT-Pb HTL,” the group emphasized. “Doping P3CT with Pb cations reduced the valence band offset with Sn-Pb perovskite and provided nucleation seeds for enhancing perovskite crystallization, resulting in improved film quality.”

The P3CT-based tandem was also found to retain around 97% of its initial efficiency after 1,000 h.

According to Song, the cost of the doping technique is almost negligible, as the lead iodide material used for doping is the same source material used for producing the perovskite absorber layer, and only a trivial amount is needed for doping. “Yet, it is worth noting that the polymer hole-transport material used in this study is still expensive due to its complexity of synthesis and limited production scale,” he further explained.

The new cell technology was introduced in the study “Suppressed deprotonation enables a durable buried interface in tin-lead perovskite for all-perovskite tandem solar cells,” published in Joule. “Our molecular design strategy for stabilizing the perovskite/HTL interface provides a direction for achieving efficient and stable all-perovskite tandem solar cells,” the team concluded.

From pv magazine Global

A research group led by Spain’s Valencia Polytechnic University has developed a novel single-parameter power forecasting method for residential PV installations.

The proposed approach defines interval prediction data rather than absolute figures, the scientists said, noting that it acknowledges and transparently communicates the natural variability in solar PV power generation.

“Opting for a single-parameter-focused model was a strategic decision aimed at simplifying the forecasting process,” highlighted the research group. “While multi-parameter models might offer more nuanced insights, they often entail increased computational complexity and resource demands. Our streamlined model promises ease of integration and user-friendliness, crucial for residential users and small-scale PV installations.”

The core aspect of the novel method is the selection of similar days in the past regarding direct radiation to forecast the power generation of a given day. A confidence level of 80% and a total of 10 similar days are selected for each prediction. After identifying similar days, the method uses a quantile-based approach to establish the prediction intervals, setting an upper and lower limit. In statistics, quantiles are used to divide the range of a probability distribution into continuous intervals with equal probabilities.

The system was trained and tested using a case study of a residential installation in Spain, which consists of 12,450 W panels and a 5 kW inverter for self-consumption, all of which installed in 2018. Hourly PV generation was recorded during the years 2019, 2020, 2021, and 2022. Hourly meteorological data for the area was obtained from the database Open Meteo.

The forecasting technique was used to predict PV power generation in 2020, based on the algorithm to search for similar days always within a range of two years before the target day. In the same period, it was compared to four classical forecasting methods: linear regression model (Alt1); gradient boosting regressor (Alt2); gradient boosting with lags (Alt3); and long short-term memory (LSTM) network (Alt4).

“The models’ performance was evaluated using Key Performance Indicators (KPIs) like prediction accuracy, prediction interval width, actual confidence level, and mean error. This thorough approach ensured a balanced assessment, emphasizing the strengths and limitations of each method,” said the researchers.

The proposed method achieved a mean absolute error (MAE) of 0.1490 kW, a mean squared error (MSE) of 0.0917 kW2, a root mean squared error (RMSE) of 0.3029 kW, an average width of intervals (AWI) of 0.3365 kW, a coverage probability (CP) of 91.55%, and an overall interval error (OIE) of 0.3789 kW. Alt1 showed an MAE of 0.3374 kW, an MSE of 0.2428 kW2, an RMSE of 0.4928 kW, an AWI of 0.9312 kW, a CP of 78.69%, and an OIE of 0.4117 kW.

Alt2 had an MAE of 0.2558 kW, an MSE of 0.2044 kW2, an RMSE of 0.4521 kW, an AWI of 0.7464 kW, a CP of 80.12%, and an OIE of 0.4031 kW. Alt3 recorded an MAE of 0.1379 kW, an MSE of 0.0768 kW2, an RMSE of 0.2771 kW, an AWI of 0.4890 kW, a CP of 91.72%, and an OIE of 0.2355 kW. Alt4 showed an MAE of 0.1282 kW, an MSE of 0.0684 kW2, an RMSE of 0.2616 kW, an AWI of 0.3522 kW, a CP of 80.72%, and an OIE of 0.2642 kW.

After analyzing the numerical results, the researchers verified how the proposed approach could help PV system owners achieve energy savings. According to their results, the average monthly energy bill decreased from $47.96 to $40,67, as energy imported from the grid decreased by 45.79 kWh, from 278 kWh to 232.21 kWh.

“By simply adjusting the operation schedules of the pool’s filtration system, the washing machine, and the dishwasher to align with peak solar production times, homeowners have been able to harness more solar energy, reducing reliance on the grid and decreasing the overall energy costs,” they concluded. “With advancements in home automation technology, even greater results can be achieved.”

Their findings were presented in “Interval-based solar photovoltaic energy predictions: A single-parameter approach with direct radiation focus,” published on Renewable Energy. The group comprised scientists from Spain’s Valencia Polytechnic University, the University of Valencia, and Ecuador’s Politecnica Salesiana University.

Indiana’s largest solar power plant about to come online Mammoth North Solar is a 400 MW agrivoltaic installation that is the first phase of Doral Renewables’ 1.3 GW solar complex.

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World’s first anode-free sodium solid-state battery Researchers at the Laboratory for Energy Storage and Conversion have created a new sodium battery architecture with stable cycling for several hundred cycles, which could serve as a future direction to enable low-cost, high-energy-density and fast-charging batteries.

Researchers build 16%-efficient mini perovskite solar module resistant to UV light-induced degradation A U.S. research team has built a 15 cm2 perovskite solar module with improved stability and efficiency thanks to a polymer hole transport layer that reportedly improves the panel stability and efficiency.

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Organic solar cell gains counterintuitive efficiency boost from entropy A research team at the University of Kansas found that organic semiconductors known as non-fullerene acceptors demonstrate a high solar cell efficiency due to a reversed heat flow.

A team of researchers at the University of Kansas have studied a counterintuitive effect in organic semiconductors that may lead to solar cell efficiencies competitive with traditional silicon solar panels. The research is published in Advanced Materials.

Researchers worldwide are actively testing alternative materials to silicon for manufacturing solar cells. While silicon offers strong efficiency and durability, there are other more abundant materials that could serve as lower-cost alternatives. Silicon is also rigid, where some photovoltaic materials have demonstrated an ability to be flexibly deposited on uneven surfaces in thin layers.

One type of material researchers are developing are called “organic” semiconductors. These carbon-based semiconductors are Earth-abundant, inexpensive, and potentially more environmentally friendly.

“They can potentially lower the production cost for solar panels because these materials can be coated on arbitrary surfaces using solution-based methods – just like how we paint a wall,” said Wai-Lun Chan, associate professor of physics and astronomy at the University of Kansas.

Chan said these organic materials can be tuned to absorb light at specific wavelengths. The materials can be used to create transparent solar panels or panels with specific colors, making them a useful fit for integrating with sustainable buildings.

Organic semiconductors are already used today in display panels of consumer electronics such as cell phones and TVs. They have not yet been commercialized in PV, as their light-to-electricity conversion efficiency sits around 12%, about half as powerful as traditional silicon solar panels.

However, the use of a new class of materials called non-fullerene acceptors (NFA) may help bridge the gap in efficiency. Organic solar cells made with NFAs have demonstrated efficiencies closer to 20%.

The significant boost in performance from NFAs occurred from a counterintuitive effect. The team found that some of the excited electrons in the material gained energy from the environment, rather than losing it via entropy.

“This observation is counterintuitive because excited electrons typically lose their energy to the environment like a cup of hot coffee losing its heat to the surrounding,” said Chan.

The researchers believe that the energy gain may be due to a quantum effect in electrons, where an electron can appear on multiple molecules at the same time. This quantum effect, combined with the Second Law of Thermodynamics, which states that every physical process will lead to an increase in the total entropy, leads to the unexpected energy gain.

“In most cases, a hot object transfers heat to its cold surroundings because the heat transfer leads to an increase in the total entropy,” said Rijal. “But we found for organic molecules arranged in a specific nanoscale structure, the typical direction of the heat flow is reversed for the total entropy to increase. This reversed heat flow allows neutral excitons to gain heat from the environment and dissociates into a pair of positive and negative charges. These free charges can in turn produce electrical current.”

The researchers said the mechanism can be utilized to make more efficient solar cells. They also believe it may be useful when applied to photocatalysts for solar-fuel production, a photochemical process that uses sunlight to convert carbon dioxide into organic fuels.

A recent report by Tennessee-based carbon solutions platform Clearloop noted that private companies have contracted for 71 GW of new renewable energy capacity in the U.S. since 2014, which is enough electricity to power nearly 15 million homes. However, the distribution of solar and wind projects tends to cluster regionally, and not only because of the availability of wind and solar resources. State and utility renewable energy policies play a huge role in where new projects are sited.

Clearloop, which is a subsidiary of solar power producer Silicon Ranch, partnered with non-profit emissions data analysis firm WattTime to study how renewable energy projects – and solar in particular – could be sited to produce better environmental and even social outcomes. The resulting white paper, Curing Carbon Blindness, reinforces the important role of private sector action in growing renewable energy in the U.S. while at the same time saying such action can be better focused to achieve decarbonization goals.

By incorporating the principle of “emmissionality,” the report suggests, companies looking to purchase renewable energy credits (RECs) or offset to their carbon footprints should seek to contract with solar and wind projects in regions with the highest percentage of fossil fuel generation.

Under the current structure, all RECs are essentially created equal, meaning an offtaker in one part of the country can buy RECs from a project anywhere else. There are differences in regional markets, such as ERCOT, but this is generally how it works. Laura Zapata, co-founder and CEO of Clearloop and one of the authors of the carbon blindness report, said not all MWh of clean energy are created equal in terms of their environmental impact.

“We still get over 60% of our electricity in this country from fossil fuels,” Zapata told pv magazine USA. “And so, our goal is how do we build more solar projects in the most carbon intense communities, which also happen to be often the most underserved and disadvantaged communities.”

Unlike most countries, the U.S. does not have a single national energy grid. It is more like a continent with many regional grids of widely varying emissions characteristics. Some regions, such as California, have grids with high percentages of renewables, while others, such as in the southern Appalachians, have fossil-fuel-heavy generation.

According to the Clearloop report, turning on a light switch in eastern Kentucky will result in 54% more carbon emissions than turning on a corresponding light in Los Angeles. This same data show that a new solar plant located in eastern Kentucky will reduce emissions by 62% more than the same plant would in Los Angeles.

By combining historical irradiance data with WattTime’s marginal emissions data, Clearloop says it is able to model not only how much electricity a solar project is expected to supply the grid, but also the marginal carbon intensity of the power generation sources it is displacing in that region at specific times.

Zapata argues that the marginal difference in emissions that results when solar generation displaces fossil fuel generation should be a key factor in citing projects. Using WattTime’s emissions analysis methodology, Clearloop had identified the regions of the U.S. where new solar, the report’s main focus, would have the greatest decarbonization impact by reducing a like amount of fossil fuel generation sources.

The analysis also extends to voluntary carbon offset markets that rely on private carbon credit registries, such as Verra or Gold Standard. This enables a company to use the methodology for contracting with solar projects to offset its carbon footprint from activities other than electricity consumption, such as air travel.

“Our clients are not interested in the electricity,” Zapata said. “What they want is credit for the environmental impact of those electrons flowing into the grid. So, whether they count them as RECs or offsets, we’re sort of agnostic.”

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Arizona’s largest energy storage project closes $513 million in financing The 1,200 MWh Papago Storage project will dispatch enough power to serve 244,000 homes for four hours a day with the e-Storage SolBank high-cycle lithium-ferro-phosphate battery energy storage solution. 

Scientists develop silver-free PEDOT:PSS adhesive for shingled solar cells Researchers from the University of California, San Diego (UCSD) have developed a new silver-free adhesive for shingled solar cells. The novel adhesive is based the PEDOT:PSS polymer and can reportedly reduce silver consumption to approximately 6.3 mg/W.

Longi launches ultra-black HPBC solar modules for residential applications The Chinese manufacturer said its new Hi-MO X6 Artist series has an efficiency of up to 22.3% and a power output ranging from 420 W to 430 W. The smaller version is currently priced at CNY 298 ($41.7)/m2 and the largest model is sold at CNY 268/m2.

Nextracker acquires solar foundation specialist Ojjo for $119 million Ojjo makes a unique truss system that reportedly uses half the steel of a conventional foundation and a design that minimizes grading requirements.

From pv magazine Global

A group of scientists from the University of California, San Diego (UCSD) demonstrated that conjugated polymers, which are a class of electronically conductive plastic materials, can be used as an intrinsically conductive adhesive (ICA) to shingled solar cells together.

“This is a new application for a unique class of plastic materials that we are very excited about,” the research’s corresponding author, Alexander Chen,  told pv magazine. “While this research is still in its infancy, one exciting aspect about this work is the deep literature and diverse chemistry that can be integrated into conjugated polymers for the purpose of making new types of conductive interconnects and adhesives.”

Shingled solar panels feature a busbar-free structure in which only a small proportion of cells are not exposed to sunlight. The cells are bonded with electrically conductive adhesive to form a shingled high-density string and the resulting strips are connected. The reduced number of busbars reduces shadowing losses.

The shingled cells used in the experiment were built with cell technology supplied by California-based startup Sunpreme and intrinsically conductive adhesives (ICAs) based on the PEDOT:PSS polymer. The performance of solar cells constructed with ICAs was compared to that of counterparts based in silver-based electrically conductive adhesives (ECAs) and the scientists found the former showed “comparable” electrical properties.

“While today’s dominant busbar-based modules require around 15.8 mg/W silver, we calculate that shingling modules with ICAs can reduce silver consumption to approximately 6.3 mg/W, accelerating our position on the silver learning curve by approximately two decades. These findings suggest that the design of pi-conjugated materials for ICAs could offer a realistic strategy for sustainable deployment of lower-cost, high-power solar modules,” the paper said.

Even with the removal of silver filler, the researchers achieved similar fill factors (FFs) and overall power conversion efficiency with shingled interconnects. “Employing a conducting polymer as the ICA additionally opens a myriad of opportunities for tuning the electronic, mechanical, and adhesive properties for designing next-generation electronic interconnects,” they added.

There are improvements to be made for the research to be applied further, as the researchers acknowledged in a statement to pv magazine. However, they are optimistic these can be made.

“While we found that the adhesion needs to be improved to reach that of commercial products, we are optimistic that designing better conjugated polymers for applications as intrinsically conductive adhesives can be achieved relatively quickly,” Chen stressed. “This area of research builds upon the incredible wealth of knowledge that already exists on tailoring the electrical properties of conducting polymers and the adhesive properties of traditional polymers. There is a large synthetic space that can be quickly explored here.”

The researchers said they collaborated with a PV engineering services company – D2Solar, Inc. – to integrate the proof-of-concept shingles. “We look forward to working with PV manufacturers to test the concept at larger scales and in relevant outdoor environments,” they added.

The ICAs were presented in the paper “Silver-free intrinsically conductive adhesives for shingled solar cells,” published in Cell Reports Physical Science.

From pv magazine Global

Longi announced at the SNEC tradeshow in Shanghai, China, that it has achieved a power conversion efficiency of 34.6% for a perovskite-silicon tandem solar cell.

The European Solar Test Installation (ESTI) has certified the results, which represent a world record for this cell typology. The previous record was held by Longi itself, which achieved an efficiency of 33.9% in November.

“We achieved this result by optimizing the thin film deposition process of the electron transport layer, developing and using high-efficiency defect passivation materials, and designing and developing high-quality interfacial passivation structures,” the company said in a statement, without providing further details.

In June, Longi reported an efficiency of 33.5% for the same cell. The European Solar Test Installation (ESTI) certified the results, which represented a significant increase on its previous 31.8% efficiency rating, which was announced during last year’s SNEC edition.

Longi has broken the world record for solar cell efficiency 16 times since April 2021. It claimed the world’s highest efficiency for silicon cells in November 2022, with a 26.81% efficiency rating for an unspecified heterojunction solar cell.

The National Renewable Energy Laboratory (NREL) has estimated that five reservoirs in Puerto Rico could host 596 MW of floating solar, although the costs would be about 25% higher than for ground-mounted solar. NREL published its analysis in a report and a technical annex.

The analysis grew out of a concern, NREL said, that “Puerto Rico’s commitment to achieving 100% clean energy by 2050 will require identification of suitable sites for new generation projects.”

An additional 190 MW of “economically viable” solar projects are possible across seven sites designated as “Superfund” sites by the U.S. Environmental Protection Agency (EPA), the study found. For six of the sites, analysts assessed “how much grant money is needed” to meet economic targets for solar projects under municipality-owned and third-party owned models.

In comparison to those estimates, both in the hundreds of megawatts, Puerto Rico has the potential for tens of gigawatts of both rooftop and large-scale ground-mounted solar, according to NREL’s “PR 100” summary report published early this year.

Across all residential buildings, Puerto Rico has the “technical potential” for 20.4 GW-dc of rooftop solar, that report estimated. A technical potential analysis does not consider the financial viability of projects. The U.S. territory reached 680 MW of rooftop solar last October.

Puerto Rico’s technical potential for utility-scale solar ranges from 14.2 GW under a “less land” scenario to 44.7 GW under a “more land” scenario, the PR 100 summary report said.

In both scenarios, modeled development of utility-scale solar was “restricted from” roadways, water bodies, protected habitats, flood risk areas, slopes greater than 10%, and agricultural reserves. But in the “less land” scenario, solar was also restricted from areas identified for agricultural use in the Puerto Rico Planning Board’s 2015 Land Use Plan.

NREL’s new analysis also estimated technical potential for 1–2.5 GW of solar across 160 contaminated sites, a total of 636 MW of floating solar on 55 water bodies, 213 MW of solar on 41 closed landfills, 78 MW of solar at two fossil generating plants once they are closed, and 21–50 MW of solar on transmission line rights-of-way.

The new NREL analysis adapted a methodology from an EPA decision tree tool titled “RE-Powering America’s Land Initiative.”

Community solar makes solar accessible to those who live in multifamily housing and don’t own their rooftops, can’t afford the upfront cost of solar or whose roofs are not oriented favorably for solar. A recent study by researchers at Lawrence Berkeley National Labs (LBNL) and published in Nature Energy, shows that community solar extends clean energy to communities that would have otherwise struggled to adopt rooftop solar.

“Their findings are compelling: community solar subscribers are 6x more likely to live in multifamily housing and 4x more likely to rent. This reaffirms what we have known to be true for years — community solar is one of the best ways to increase equity in our energy system,” said Molly Knoll, vice president of policy for the Coalition for Community Solar Access (CCSA).

Wood Mackenzie found that the share of community solar serving low-to-moderate income (LMI) subscribers grew from 2% to 10% in just one year, with costs decreasing 30% over the same period. In a report on community solar, Wood Mackenzie expects 7.6 GWdc of new community solar will come online in existing state markets between 2024 and 2028, and the national total of community solar installations are expected to pass 10 GW of cumulative capacity in 2026.

The Wood Mackenzie report noted that residential customers are representing an increasingly larger share of community solar subscriptions, suggesting a shift in focus for developers and providers. Low- and middle-income (LMI) customers rose from 2% of the customer base to 10% from 2022 to 2023, with costs to subscribe these customers declining 30% year-over-year.

Knoll pointed out that the Wood Mackenzie findings along with the LBNL findings, shows that policy that supports community solar adoption by LMI customers cannot only increase solar adoption but can also decrease overall costs.

For the first time, the researchers combine household-level data from Berkeley Lab’s Tracking the Sun rooftop solar adopter data set with data compiled under NREL’s Sharing the Sun community solar research, as well as additional community solar adopter data collected for the study. To determine how well community solar is serving the needs of those who are underserved by the rooftop solar market, the study looked at the demographic characteristics of the two adopter groups.

Based on a sample of 11 states, the LBNL study found that community solar adopters in 2023 were about 6.1 times more likely to live in multifamily buildings than rooftop solar adopters, 4.4 times more likely to rent, and earned 23% less annual income. Based on this, the researchers conclude that community solar has effectively expanded solar access to multifamily housing occupants, renters and low-income households.

The researchers also looked at what drives community solar participation: business models or policy. The business model removes barriers to adoption by allowing households to adopt solar without owning a home or having exclusive access to a rooftop. This is especially appealing to those who live in multifamily buildings and/or who are renters.

On the other hand, the researchers found that policy has helped to provide targeted support to help low-income households adopt community solar.

The conclusion was that business models and policy are equal in influencing community solar.

According to CCSA’s Knoll, this equitable access will increase substantially as more state policies include requirements that projects serve LMI customers. She noted that the $7 billion infusion from the EPA’s Solar for All competition will further speed LMI adoption.

“This study is important confirmation of one of the values community solar can bring to the electric grid and the tireless work our broad and diverse coalitions are doing to bring community solar to every state in the country,” said Knoll.

The authors of the Berkeley Lab study will host a free webinar on June 18^th at 11 a.m. PT/2 p.m. ET.

CPUC vote expected to keep California community solar from reaching its full potential Coalition for Community Solar Access says the 3-1 vote ignored the will of the California Legislature and the broad coalition of ratepayer, equity, environmental, labor, agricultural, and business groups who have demanded a functional community solar program for more than a decade.

Alliant Energy completes 200 MW solar project in Wisconsin  The project is part of a multi-phase buildout of 12 solar projects totaling over 1 GW.

Long-duration energy storage poised to outcompete lithium-ion batteries While most long-duration energy storage (LDES) technologies are still early-stage and costly compared to lithium-ion batteries, some have already or are set to achieve lower costs for longer durations, finds BloombergNEF.

Solar wafer prices continue to soften, complex international trade situation sparks concerns  In a weekly update for pv magazine, OPIS, a Dow Jones company, provides a quick look at the main price trends in the global PV industry.

Gulf heat dome and polar jet stream shape solar outcomes in May In a weekly update for pv magazine, Solcast, a DNV company, reports that a strong polar jet stream and a record-breaking heat dome in May resulted in a stark contrast in irradiance patterns across North America. The western and central USA, along with Mexico, experienced higher than normal irradiance, while the Gulf and East Coast regions faced lower irradiance.

TCL Zhonghuan reveals plans to acquire majority stake in Maxeon Chinese wafer manufacturer TCL Zhonghuan says it wants to invest around $197.5 million to increase its stake in Maxeon from 22.39% to at least 50.1%. A Maxeon spokesperson told pv magazine that the plan would place the company in a solid financial position.

Are false pretenses driving solar cell tariff case? Global manufacturer Canadian Solar challenges prevailing support for tariffs among solar manufacturers, questions the accuracy of capacity estimations, and adverse financial effects.

Scientists from Arizona State University published a paper about solving mechanical-based failure mechanisms to make metal halide perovskite (MHP) modules and cells more stable and reliable.

The team asserted that the future of stable and efficient perovskite solar modules lies in understanding the interconnection between various degradation modes, mechanical, thermal, and chemical, under light, heat, and humidity stressors.

“We noticed that there is a significant acceleration in failure rates and reduction in lifetimes of perovskite solar modules in the field when compared to those tested in the lab,” the lead author of the paper, Marco Casareto, told pv magazine. “Specifically, there is little work on testing modules under multiple environmental stressors, such as both light and thermal fluctuations. We wanted to draw attention to this crucial area of research in the hopes of accelerating the progress and commercial viability of MHPs.”

“Yes, and we believe that these factors are connected, based on a shared underlying mechanism related to the mechanical properties of an MHP module,” research co-author, Nick Rolston, told pv magazine.

Their paper highlights issues related to the low fracture energy (Gc) of material layers and interlayer adhesion. “Gc is a material’s resistance to the propagation of a crack, dependent upon both material/interface bonding energy and the ability of a material to deform,” the research group explained.

In addition, it discusses the negative impact of film stresses within the perovskite absorber, how scribing removes material introducing even more interfaces for stress, and the importance of realistic accelerated degradation testing in the lab.

Realistic testing of devices with multiple simultaneous stressors is “crucial” to simulate operation in the field and achieve commercial maturity, emphasized the team. It proposed setting a minimum G_c of 1 J/m² for devices in the lab to ensure that modules can withstand processing and packaging steps without mechanical failure, as well as reduce the potential for delamination and accelerated degradation.

The researchers propose that “engineering compressive stress” and “tuning layer properties” could improve thermomechanical reliability. They also describe encapsulant and perovskite solar module (PSM) materials strategies to increase toughness.

Their findings appear in “Designing metal halide perovskite solar modules for thermomechanical reliability,” published in communications materials. 

When asked about reactions to the publication, Rolston said, “We haven’t had much feedback yet since the paper was just released; however, we have been discussing these results with several of the MHP startups that are working toward commercializing the technology, as well as the Perovskite PV Accelerator for Commercializing Technologies (PACT),” referring to the multi-year US Department of Energy’s PACT accelerator, led by Sandia National Laboratories.

There is still a long way to go, as Rolston sees it, but there is optimism about the development of MHP PV panels with operational lifetimes comparable to incumbent silicon or cadmium telluride (CdTe), if there is more of an effort in designing for thermomechanical reliability, rather than just for performance.

Looking ahead, Casareto said, “We’re currently working on validating our hypothesis of a mechanical-based failure mechanism. This involved fabricating MHP individual cells without scribing or encapsulation to establish a baseline of how they degrade under thermal cycling once encapsulated. We are now doing the same with modules soon to elucidate any differences in degradation mechanisms/severity of modules under thermal cycling. We aim to examine the effect of encapsulation, particularly at the scribe lines, as a module is thermally cycled to evaluate what properties are most important/beneficial for a PSM encapsulant.”

U.S. scientists develop air-bridge thermophotovoltaic cells with 44% efficiency  U.S. scientists have developed a thermophotovoltaic cell that could be paired with inexpensive thermal storage to provide power on demand. The indium gallium arsenide (InGaAs) thermophotovoltaic cell absorbs most of the in-band radiation to generate electricity, while serving as a nearly perfect mirror.

Guaranteed and transferable tax benefits will make the PV industry too big to fail  Trina Solar executive says policies in the Inflation Reduction Act will make or break the future of solar in the U.S.

Largest solar project in Wyoming moves forward  The $1.2 billion Cowboy solar project will be built by Enbridge, with 771 MW expected to be fully operational by 2027.

21 states accept the grid modernization challenge The Federal-State Modern Grid Deployment initiative aims to shore up the U.S. energy grid to prepare for both challenges and opportunities in the power sector.

Battery energy storage tariffs tripled; domestic content rules updated Breaking down U.S. market impacts on energy storage from recent policy changes with insights from Clean Energy Associates.

Texas is the proving ground for a new way of electric grid operation Texas is uniquely suited to adopt virtual power plant technology due to its competitive, deregulated market. Its success highlights the “perverse incentive” of vertically integrated utilities in other states to make capital expenditures without discretion to raise profits.

From pv magazine

World records for perovskite solar cells have a short shelf life. Until April 2022, a silicon-perovskite tandem cell from Helmholtz-Zentrum Berlin (HZB), a German research organization, led with an efficiency of 32.5%. Researchers at the Photovoltaics Laboratory of the King Abdullah University of Science and Technology (KAUST), in Saudi Arabia, later hit 33.2%, and then 33.7% in May 2023. That record stood for a few months. In early November 2023, a perovskite-silicon tandem cell from Chinese PV manufacturer Longi converted 33.9% of incident sunlight into electricity. “This means that the solar cell efficiency of silicon perovskite tandem cells is now in ranges that could previously only be achieved with III-V semiconductors,” said HZB managing director Bernd Rech, referring to materials such as gallium-arsenide, which offer strong solar cell performance at a much higher cost.

Even single-junction perovskite solar cells without the crystalline silicon or other tandem element are attracting commercial interest. Record after record fell in quick succession in 2023, albeit in increments of tenths of a percentage point. Since November 2023, a group from the Key Laboratory of Photovoltaics at the Hefei Institute in China, with support from German, French, and South Korean scientists, has held the world record with 26.1% efficiency. The successes are based on clever design and the purity of the perovskite crystals. The crystals are, in principle, based on diverse, highly optimized production processes that make it possible to minimize impurities and other defects, which are the most important cause of recombination – where a charge is lost before it can be transported out of the cell.

Knowledge of the fundamental processes within perovskite materials is also growing. For example, Thomas Kirchartz and his team at Germany’s Jülich Research Center discovered a major difference between perovskites and other solar cell materials. In a paper published in the journal “Nature Materials” in January 2024, the group outlined differing roles for “deep” and “shallow” cell-material defects. Kirchartz suspects deep defects, which can occur in silicon, cannot exist in perovskites. “Understanding the processes is crucial to further improving the efficiency of perovskite-based solar cells,” he said.

Lab to fab

“Perovskite solar cells can become a game changer in photovoltaics,” said Michael Powalla, a board member at the Center for Solar Energy and Hydrogen Research Baden-Württemberg in Stuttgart. Values of more than 33% in perovskite-silicon tandem cells could give modules up to 30% efficiency. Most records to date, though, have been achieved with prototypes typically measuring around 1 cm². There is no shortage of unsolved challenges for cells hundreds of times larger. Research institutes and PV companies large and small want reliable, cheap, fast production processes for large cells. Another unresolved issue is the guaranteed durability of perovskite modules that would age as little as possible and give high electricity yields for at least 25 years. “We need everything at the same time: high efficiency, outdoor stability, and scaling with compatible production processes,” said Powalla.

Simple, inexpensive spin coating is sufficient for small tandem laboratory cells. In this process, solutions are thinly ­distributed on a fast-spinning surface. For larger cells, with an edge length of more than 15 cm, other, less wasteful processes are required. With recent commercial silicon cells boasting up to 21 cm edge lengths, large-area processes are more important.

“Several processes are suitable for this and are currently being tested,” said photovoltaics researcher Kaining Ding, from the Jülich Research Centre. The challenge is that the perovskite crystals must evenly cover the textured surface of the silicon cell without gaps. If the perovskite layer is too thin, the tips of the pyramids on the silicon surface – which are less than 1 micrometer in size – could puncture the perovskite layer and reduce efficiency. On the other hand, if the layer is too thick, it becomes more difficult to collect charge carriers efficiently.

One variant is slot die coating, in which a perovskite solution is applied as an ink-like liquid, and forced through a slot to be evenly applied to a substrate. What then becomes difficult is to precisely control perovskite layer thickness with the process, especially at edges. Perovskite layers can be applied more evenly under vacuum from a vapor phase using a physical vapor-deposition process. The challenge here is finding a perovskite precursor solution that can be completely converted into the necessary vapor phase.

“There is also a hybrid approach that combines the advantages of both process types,” said Ding.

First, a thin, porous, inorganic precursor layer is deposited as a vapor. This is followed by a liquid phase that can be applied by slot die coating or other print- or spray-type processes. This liquid migrates into the porous layer, causing the desired perovskite crystals to grow. Ding said many solar companies are focusing on this hybrid method of wet chemistry and vacuum processes and hope to apply it to full-sized tandem cells in the near future.

A new approach developed by a research group led by Ulrich W. Paetzold, from the Karlsruhe Institute of Technology in Germany, also promises to accelerate developments. The group trained an artificial intelligence device to recognize the smallest deviations in light emission by the cells during the production of tandem devices. The quality of a solar cell could thus be quickly deduced from the light emission.

“Thanks to the combined use of AI, we have an idea of which adjustments we need to make, first and foremost, to improve production,” said Paetzold. This means that experiments can be carried out in a more targeted manner and that production routes can be identified more quickly.

PV modules

Large perovskite silicon tandem cells, or even entire modules, are still hard to find. Anglo-German company Oxford PV has a clear lead, having set up the world’s first series production line for perovskite silicon tandem cells in Brandenburg an der Havel, Germany. At 28.6%, Oxford PV also holds the world record efficiency for a large tandem cell, with a surface area of just over 285 cm².

Others are catching up. In May 2023, Chinese startup Auner presented a tandem cell with a 5 cm edge length and 30.83% efficiency. The company plans to launch a 100 MW pilot production line producing 166 mm cells later in 2024. Swiss manufacturer Meyer Burger also presented a medium-sized (24.5 cm²) cell with 29.56% efficiency as early as 2022, in collaboration with Swiss research center CSEM. Japan-based Kaneka, meanwhile, has hit 28.4% on an 8 cm cell.

Manufacturers of pure perovskite solar cells are striving for faster series production using wet chemical processes such as slot die coating. This is where Chinese companies are making a leap into the market. Last year, for example, Microquanta Semiconductor, based in Hangzhou, started series production of perovskite modules measuring 1.2 m by 60 cm, albeit with efficiencies of less than 20%. Since November 2023, a 1 MW power plant in the Kubuqi Desert in Inner Mongolia featuring those modules has been supplying not only electricity but also valuable data on the durability of perovskite solar cells under real-world conditions.

Silicon solar manufacturer GCL Group has also joined the ranks of perovskite producers with modules measuring 1 m by 2 m and achieving efficiency of 18.04%. The company says a 2 GW production line is currently being prepared in Suzhou, China. Utmolight, which was only founded in 2020, plans to start building a 1 GW production line in 2024 in Wuxi, China, set for completion in 2027. Another 100 MW pilot line is planned for 2024 by startup Mellow Energy. It is targeting 20% module efficiency from modules measuring 1.2 m by 1.6 m, having demonstrated efficiency of up to 22.86% on smaller devices. While those figures are barely competitive with today’s silicon modules, let alone tandem devices, they do offer significantly lower production costs.

Achieving stability

“None of these companies can guarantee the stability of their modules for 25 years,” said Jülich’s Ding. Despite promising results in the laboratory, the durability of perovskite solar cells remains a challenge – both alone and in tandem devices. There is a lack of concrete information from the manufacturers, as well as a lack of measurement data from long-term outdoor use or standards for tough tests that simulate real-life loads of up to 25 years. Laboratory tests on small cells do, however, show how perovskite solar cells can be stabilized, for example, with the addition of certain chemicals. “But there is a gulf between research and industry,” said Ding. Many promising approaches are simply not pursued after publication in renowned scientific journals.

That is precisely the problem that Ding and his colleagues at Jülich and at the HZB want to tackle. Michael Saliba from the University of Stuttgart is also convinced that, with the progress made over the last few years, 20-year stability could, in principle, already be achieved today – provided that the available knowledge is utilized in a bundled manner for the development of sophisticated manufacturing processes.

This means that the hurdles to the low-cost series production of perovskite solar cells – alone or in tandem – appear to be surmountable in the next few years. In a recent paper published in the journal “Science,” Erkan Aydin and his colleagues at KAUST estimated the point at which perovskite-silicon tandem cells will be economically viable compared to standalone silicon. He calculated that higher production costs constitute a premium of 30%. The result is that if a tandem cell loses 2% of its (relative) efficiency every year, the new module should already have an efficiency of more than 32%. If long-term stability can be improved – for example, if a module only degrades by 0.4% per year, similar to today’s silicon PV products – then 24% efficiency would already be sufficient. Then, as forecast by analysts at Rethink Energy, in the United Kingdom, the target of 2 GW of global production by 2026 could easily be achieved. By 2040, some 90% of all solar modules could even contain perovskites.

By Jan Oliver Löfken.

California’s recent strides in emission-free electricity and energy storage have garnered global attention, from top-tier publications to outlets on the other side of the globe.

According to data from the California Independent System Operator (CAISO) and record keeping by Stanford Professor Marc Jacobson, “for 45 days straight and 69 of 75, California #WindWaterSolar (electricity) supply has exceeded demand part of each day. On May 20, (supply exceeded demand for) 7.58 h, peaking at 135.4% of demand. On average over 75 days, WWS>demand for 5.3 h/day.”

This performance is bolstered by the extensive use of batteries during the evening electricity peak demand period. As seen in the chart above, the batteries (seen in dark blue) play a crucial role during these ramping periods.

Essentially, the engineers managing California’s power grid have adapted to harness inherently unpredictable power sources.

When it comes to solar, these impressive figures still underestimate the impact of sunlight. This is because they only account for utility-scale generation, with rooftop and behind-the-meter projects contributing an additional 15 GW of capacity worth of electricity – almost equal to utility scale capacity.

For utility-scale supplied solar power, April in CAISO showcased an impressive performance. Generally, April is the third-highest month for solar as a percentage of all electricity, per data from pv magazine USA’s 50 States of Solar report.

However, this past April, the instantaneous “All-Time Max Demand” record was broken four times, rising from an 80.4% record set in April of 2022, to a new record of 97.5% on April 20th this year.

This raises an interesting question: why did ‘All Time Max Demand Served’ jump so significantly this year, especially after it had remained mostly static throughout 2023? It all boils down to increased battery capacity, which has allowed solar to expand its influence more effectively. Notably, we recently saw utility-scale battery capacity surpass 8 GW, which has now began to offset the evening peak demand periods.

Since the electricity for these batteries primarily comes from solar power, perhaps we should also consider that solar is meeting the evening peak demand?

pv magazine USA conducted an analysis of CAISO generation data and discovered that on April 21, solar electricity actually peaked at more than 123% of total electricity generation.

Solar can supply more than 100% of demand due to the net effect of batteries charging. On this date, solar also accounted for almost 38% of all electricity generated within the CAISO region, marking the peak value for the month. Additionally, the following day, CAISO recorded a new high for peak solar output at 18,374 MW.

The chart also highlights the April 8th eclipse – noted with a large dip in generation in light blue around 11 a.m. PST.

According to gridstatus.io, April 21st also marked a new record for battery output at 10:10 p.m., reaching 6,458 MW. This record has since been surpassed multiple times, with the current peak now at 7,528 MW. This record is expected to continue to grow as more utility-scale energy storage is deployed this year.

Over the entire month of April, solar was the largest source of electricity by far, contributing just over 31%. In total, solar combined with hydro, wind, nuclear, and geothermal provided almost 70% of the electricity, with methane generating 19%. Given that imports historically are historically 50% emission-free, this would put the total emission-free electricity used in California in April at approximately 75%.

From pv magazine Global

A group of researchers led by Spain’s Centre for Energy, Environmental and Technological Research (CIEMAT) has assessed the performance of 23 partially repaired crystalline silicon solar modules at a 12-year-old PV plant in Spain and has found these panels can operate with minimal losses.

“This research employs a comprehensive standardized approach,” the scientists explained. “It integrates visual inspection, electrical testing, electroluminescence imaging, and thermal imaging techniques to thoroughly evaluate the functional status of these modules and define the nature and extent of defects that persist post-repair.”

The test was conducted following IEC 61215 standard on 18 monocrystalline panels and 5 polycrystalline devices. The monocrystalline products came from two different manufacturers. All panels had a backsheet-glass configuration and their weight ranged from 21 kg to 25 kg. The group also applied the MQT 03 and MQT 15 Module Quality Test standards.

Module failures were identified according to the following classification: snail trails; browned EVA and broken cell; burnt cell; delamination and corrosion as a consequence of EVA degradation; bubbles formation, cracking and burn in the backsheet. “This categorization delineates the progression of power loss from the initial level to a specific point in the operational lifespan of a PV module,” the academics specified. 

Through the visual inspections, the team found that the modules showed optical degradation due to delamination and discoloration of the encapsulant. Moreover, it also ascertained that all of the 23 PV modules evaluated passed the dry insulation test, while only one passed the wet leakage current test.

“All modules analyzed exhibit exposed welds on the back sheet, due to bus bar interruption repair,” the researchers stressed. “This condition is not a failure due to the degradation of the module itself but rather a result of the subsequent partial repair, which caused the insulation to fail, making electrical isolation impossible. To fix the insulation of these modules, it is necessary to continue with the backsheet repair, sealing the exposed solder joints and re-testing the modules for wet leakage current.”

The I-V Curve measurements showed that the modules did not suffer from anomalies, although a power reduction was detected, while electroluminescence imaging (EL) demonstrated that around 73% of the panels presented microcracks and darker areas on the periphery of the solar cells.

When they used infrared thermography imaging, the researchers found that “strong hot spots” were detected for 4.35% of the analyzed panels, while “light hot spots” were identified for 74% of the modules. “In this last group, we found that 47 % had featured high temperatures in the junction boxes, attributable to the diode’s activation and further energy dissipation,” they added.

All in all, the analysis showed that the most common defect in the repaired modules is moisture-induced degradation (MID), followed by cracked cells and disconnected areas in cells.

“However, despite the presence of defects, around 87 % of these modules exhibit a reduction of less than 20 % in power,” the scientists stated. “This significant finding suggests that the repaired modules successfully meet the manufacturer’s warranty criteria, indicating their potential for reuse.”

The group also warned, however, that there is an urgent need to define a protocol for evaluating the features of a “viable” repaired panel. “Additionally, it is necessary to raise awareness regarding international standards and Cradle-to-Cradle certification, as this has the potential to stimulate the market demand for second-hand modules with improved sustainability and circularity attributes,” it concluded.

Their findings are available in the paper “Enhancing Photovoltaic Module Sustainability: Defect Analysis on Partially Repaired Modules from Spanish PV Plants,” published in the Journal of Cleaner Production.

Another research team at CIEMAT recently developed a set of techniques to repair ribbon busbar interruptions in PV panels without resorting to expensive electroluminescence images.

From pv magazine global

A new report from BloombergNEF says achieving net-zero by 2050 hinges on renewables capacity tripling between now and the end of the decade.

Its latest New Energy Outlook presents a pathway to net-zero by 2050 called the “Net-Zero Scenario” (NZS). It says the window to reach the target is “rapidly closing,” but adds there is still time “if decisive action is taken now.” BloombergNEF warns it will not be possible without accelerated spending, with a fully decarbonized global energy system by 2050 estimated to have a $215 trillion price tag. To reach net zero by 2050, it says progress in the next 10 years is “critical.”

“The period 2024-30 is dominated by rapid power-sector decarbonization, energy efficiency gains and rapid acceleration of carbon capture and storage deployment,” the report says. “Wind and solar alone are responsible for half of emissions abatement during this seven-year period.”

It explains that with renewables driving the bulk of emissions cuts this side of 2030, there will be more time to tackle “hard-to-abate” areas such as steelmaking and aviation, where cost-competitive low-carbon solutions have yet to scale.

BloombergNEF’s NZS says that while the deployment of renewables will continue into the 2030s, the focus will switch to electrification, with electrifying end uses in industry, transport and buildings accounting for 35% of the emissions avoided during this period. It then predicts that the 2040s will rely on a mix of different technologies aimed at hard-to-abate sectors, where hydrogen will account for 11% of emissions reductions.

The report lists nine technology pillars for a net-zero world, which would work to address different elements of the carbonization challenge. BloombergNEF says four of the nine pillars – renewables, energy storage, power grids and electric vehicles – are already “mature, commercially scalable technologies with proven business models.” These are described as technologies which require a significant acceleration to get on track for net zero, but there is little to no technology risk, economic premiums are small or non-existent, and financing models are already at scale.

S will require 2.9 million square km of land for solar and onshore wind projects by 2050, almost 15 times more than was being used by the two technologies in 2023.

It warns that land constraints in some countries – namely, South Korea, Vietnam and Japan – may mean the total land area suitable for solar construction could face saturation, indicating a greater share of less land intensive technologies will be needed in the future. The report says one solution may be using land for solar that can also be used for crops.

“The way in which these segments compete for, and co-exist on, the same land will shape future permitting and zoning rules, particularly if the rollout of low-carbon technologies is seen to threaten food security,” the report predicts.

BloombergNEF also says regardless of whether the world heads for net-zero or it ultimately proves a stretch too far, “the era of fossil fuels’ dominance is coming to an end.” The report predicts that even if the net-zero transition is propelled by economics alone, with no further policy drivers to help, renewables could still cross a 50% share of electricity generation by the end of this decade.

The U.S. recently exceeded five million solar installations, with the residential sector accounting for 97% of all solar installations in the U.S., according to data from the Solar Energy Industries Association (SEIA) and Wood Mackenzie.

A recent report, The state(s) of distributed solar—2023 update from the Institute of Local Self Reliance (ILSR), estimates that 29 GW of solar capacity was installed in 2023; 31% of which is distributed solar. Distributed solar is solar that is owned by individuals, small businesses and public entities—and is generated at or very near the site where it is used.

The map below shows how much distributed solar was installed in each state through 2023, relative to population.

For the purposes of the map, community solar in Colorado, Hawaii, Illinois, Maryland, Massachusetts, Minnesota, New Jersey, New York, and Oregon is included as distributed solar.

To arrive at these figures, ILSR added its own figures on state community solar capacity to the U.S. Energy Information Administration’s (EIA) figures on small-scale photovoltaic capacity by state. This sum was divided by state population estimates from the U.S. Census Bureau, resulting in a figure of watts per person. The U.S. EIA did not collect data from Alabama or North Dakota.

A key finding is that 21 states and the District of Columbia have a distributed solar saturation of more than 100 watts per capita.

California, Arizona, Nevada, and Massachusetts all land in the top ten for both distributed solar saturation and total solar generation capacity.

California, Texas, Florida, and North Carolina have the largest overall capacity whereas Hawaii, Massachusetts, Rhode Island and California have the greatest distributed solar saturation, as measured in installed distributed solar capacity per capita.

Several state solar markets have made significant changes since ISLR’s 2022 update. Installed distributed capacity grew by more than 1 GW in Texas (6 GW), California (4.7 GW), Florida (2.5 GW), Ohio (1.8 GW), Virginia (1.2 GW), and Colorado (1.1 GW).

Five states doubled or more than doubled installed capacity in 2023, including South Dakota, Ohio, Pennsylvania, West Virginia, and Arkansas. While doubling capacity is good news, it still may not amount to much as both South Dakota and West Virginia are considered “solar laggards” according to PV Intel’s analysis, based on EIA data.

Other states that saw strong growth include Wisconsin, Indiana, Montana, Louisiana, Maine, and Michigan.

Community solar

Community solar provides a way for people to benefit from solar energy who may be unable to install solar either due to financial restrictions or because they do not have a suitable rooftop for solar.

ILSR’s 2024 Community Power Scorecard states that “a model community solar policy has no cap, has a fair compensation rate, simplifies the billing process for subscribers, meaningfully accounts for the challenge of reaching low- and moderate-income (LMI) subscribers, and rewards other beneficial development or small subscriber-friendly practices”.

ILSR reports that state policies like community solar, net metering, simplified interconnection rules and a renewable portfolio standard carve-out for distributed energy are crucial in promoting the adoption of distributed solar.

The distributed solar report notes that 19 states and the District of  Columbia currently have community solar policies and highlights nine states that ILSR calls “solar-enabling” for their strong community solar policies and installed capacity.

Total installed community solar capacity at the end of 2023:

1. New York 1.72 GW
2. Minnesota 904 MW
3. Massachusetts 852 MW
4. Illinois 251 MW
5. Maryland 149 MW
6. Colorado 147 MW
7. New Jersey 137 MW
8. Oregon 29 MW
9. Hawaii 4 MW

ILSR tracks these policies and others in its Community Power Map. According to the ILSR’s Community Power Scorecard, 26 received failing grades in 2024, suggesting that many states have much room for improvement.

ILSR’s State(s) of Distributed Solar analysis is updated annually. For a historical snapshot, explore archived analyses of distributed solar by state in 2022, 2021, 2020, 2019, 2018, 2017, and 2016.

From pv magazine Global

A team from Johannes Kepler University Linz, Austria has developed lead halide perovskite solar cells that measure less than 2.5 μm thick with a champion specific PV power density of 44 W/g, and an average performance of 41 W/g, which they were able to integrate into modules to power palm-sized quadcopter-style drones.

The technology exhibited promising stability results under several standard tests, as well as the energy harvesting potential sufficient to recharge the vehicle’s batteries. The details of their research appear in “Flexible quasi-2D perovskite solar cells with high specific power and improved stability for energy-autonomous drones,” published in nature energy.

The study’s large-area photovoltaic module, which measured 24 cm2, enabled the autonomous operation of the drone that extended “beyond what is possible on a single battery charge while eliminating the need for docking, tethered charging or other forms of human involvement.” The perovskite solar modules contributed just 1/400th of the drone’s total weight.

The group tested several alpha-methylbenzyl ammonium iodide (MBA) combinations in the top perovskite absorber layer, with PEDOT:PSS combining hole transport and electrode functions. The longest lifetime of the various MBA formulations included cesium (Cs), indicating “a reduction of non-radiative recombination pathways due to the presence of MBA and Cs”, according to the researchers.

The substrate was an “ultrathin” and transparent-conductive-oxide-free 1.4-μm-thick polymer foil coated with a layer of 100 nm aluminum oxide. It effectively served as a “barrier” to moisture and gases.

“This type of device has no room for typical encapsulation approaches, which are just too thick. Instead, the team relied on the MBA perovskite top layer’s large, bulky crystal formation to effectively passivate the surface, and for the substrate, the aluminum oxide layer applied with atomic layer deposition (ALD) tool serves to protect from the external conditions, but still stay lightweight and flexible,” research leader, Martin Kaltenbrunner, told pv magazine.

Indeed, the paper notes, for example, that the water vapor transmission rate (WVTR) of the “coated ultrathin substrate was measured to be about 35% lower” when compared to the reference designs, which were methylammonium lead iodide (MAPbI3) devices.

Other features of the perovskite cell include an electron transport layer made of phenyl-C61-butyric acid methyl ester (PCBM) with a titanium oxide interlayer, and a metal top contact, which the group pointed out could be made interchangeably of gold, or chromium/gold, or low-cost aluminum.

“It is important in our perovskite solar research to use precursors that are synthesized in as few steps as possible. Straightforward synthesis is key because we want the technology to be scalable and to keep material production costs in check,” said Kaltenbrunner.

From cells to module

The study’s small area perovskite solar cell measured 0.1 cm2 with an open circuit of 1.13 V, a short-circuit current density of 21.6 mA cm−2, a fill factor of 74.3%, and a power conversion efficiency of 18.1 %. The champion cells reached an open-circuit voltage of 1.15 V, a fill factor of 78%, and an efficiency of 20.1%.

The larger device had an active cell area of 1.0 cm2, with a mean open-circuit voltage of 1.11 V, a short-circuit density of 20.0 mA cm−2, a fill factor of 65.9%, and an efficiency of 14.7. The champion device reached an efficiency 16.3%, stated the research team.

The module for powering the drone had 24 interconnected 1 cm2 solar cells. The energy-autonomous hybrid solar-powered commercially available quadcopter-type drone weighed just 13 g.

The stability and prolonged outdoor operability were tested. For example, both the small- and large-area unencapsulated solar cells maintained 90% and 74% of initial performance, respectively, after 50 h continuous maximum power point tracking (MPPT) in ambient air. In addition, an external lab validated performance and properties of the perovskite composition.

The team asserted that it demonstrated the “broader benefits of using a quasi-2D perovskite active layer” and that it outperforms “other compositions in this field”, adding that the performance, stability, and usability of the ultra-lightweight perovskite solar technology is both a “portable and cost-effective sustainable energy harvesting” solution.

As a drone charging system, it is a step on the path to “perpetual-operation vehicle development” for both aerospace and terrestrial applications, it asserted.

The team has plans for further research along these lines. “We will continue to work continue to develop the AlOx barrier substrate technology, scalable deposition techniques, and to scale up to even larger modules, measuring at least 10 cm X 10 cm. We are intent on the development of lightweight, flexible PV solutions to power all kinds of robotics and autonomous vehicles,” said Kaltenbrunner. “There is great potential for deployable, flexible solar PV in both earth and space applications.”

A team of researchers at the University of Ottawa are testing the use of artificial reflectors to boost solar production. The study was published in Progress in Photovoltaics.

In Canada and other northern climates, it is common to use bifacial solar panels, which can collect light and convert it to electricity on both sides of the panel. These cold climates often have snow on the ground, creating a highly reflective surface that boosts bifacial production.

University of Ottawa’s Sunlab, along with the U.S. National Renewable Energy Laboratory (NREL), collaborated on a project that tested the efficacy of creating artificial surfaces that can mimic the benefits of the high reflectivity of snow.

“High-albedo locations demonstrate a boost in performance, with bifacial gains reported of over 19% in snowy months,” said the report. “The bifacial PV industry has demonstrated an interest in extending this energy gain to non-snowy locations year-round using artificial reflectors.”

The team found that placing white reflective surfaces directly under solar panels can increase total energy output by up to 4.5%.

The study calculated a maximum viable cost for these improvements of up to $2.50 to $4.60 per squared meter, including both material and installation, at the Golden, Colorado test site.

“Higher breakeven material costs are possible in systems with higher initial levelized cost of electricity (LCOE). For example, we found breakeven installed costs of $3.40–$6.00 squared meter for Seattle, Washington, with 60% reflective material.”

 The impact of artificial reflectors depended strongly on location, with locations with higher LCOE and lower energy yield benefiting more from the addition of reflectors than locations with low LCOE and high energy yield.

“We found that highly reflective white surfaces can boost solar power output,” said Mandy Lewis, the study’s lead author. “Critically, these reflectors should be placed directly under the solar panels, not between rows, to maximize this benefit.”

Lewis said the research will be helpful in boosting solar production in geographically diverse regions. Generating more power per unit of land area makes reflectors a potential match for densely populated areas, where space limitations exist for solar installations, said Lewis.

The report found that 70% reflective material can increase total incident irradiance by 1.9% to 8.6% and total energy yield by 0.9% to 4.5% annually after clipping is considered with a DC–AC ratio of 1.2.

“Clipping has a significant effect on reflector impact and must be included when assessing reflector viability because it reduces reflector energy gain,” said the report.

The U.S. Department of Energy’s Solar Energy Technologies Office (SETO) recently announced the 2024 Photovoltaics Research and Development program. This new initiative aims to distribute $20 million across eight to fifteen teams, with individual grants ranging from $1 to $4 million.

SETO has outlined two main focus areas for this funding: “Photovoltaic Advances in Cell Efficiency, Reliability, and Supply Chain,” and “Building Academic Capabilities in Cadmium Telluride”.

The first area seeks to develop solar cell and “minimodule” prototypes aimed at lowering module costs and the carbon footprint of manufacturing and supply chains. This includes advancements in building-integrated and vehicle-integrated solar systems. SETO is particularly interested in projects that promise low-carbon synthesis of metallurgical-grade silicon and innovative designs for crystalline, III-V, and organic solar photovoltaic cells.

The initiative also aims to address the high costs of III-V solar cells, currently priced at $77/Wdc, making them non-competitive for terrestrial solar generation. For metallurgical-grade silicon, the goal is to reduce CO2 emissions from the current 4 to 5 kg CO2 per kg of 2N c-Si (solar-grade silicon) to less than 1 kg CO2 per kg of silicon. It is expected that between six and ten awards will be distributed, ranging from $1 to $1.5 million each, totaling $10 million.

The second focus area targets advancements in cadmium telluride technology, which could greatly benefit First Solar, America’s leading solar panel manufacturer. This funding will support projects that require the development or upgrade of cadmium telluride research facilities. The objective is to enhance the design and testing processes within the cadmium telluride research community, facilitating rapid advancements and technology transfer.

Additional priorities under this funding include:

• Increasing the rate of learning and speed of advancement in CdTe cell and module research. 
• Improving the efficiency, durability, and energy yield of state-of-the-art CdTe PV cells. 
• Developing and validating new CdTe PV cell designs that have the potential to substantially outperform the current state of the art.  
• Improving the quality and scale of materials produced at academic institutions to facilitate technology transfer to industry.

For this second topic, SETO expects to allocate two to five awards, each ranging from $1 to $ 4 million, with a total allocation of $10 million.

Key dates for the program are:

Independent clean energy think tank Ember released a report recapping the growth of renewable energy worldwide, reporting that renewable energy generated about 30% of electricity across the globe in 2023.

Solar generation growth increased 23% globally, wind grew 10%, while fossil fuel generation grew only 0.8% last year, said the report. Renewables have expanded from 19% of global electricity in 2000, driven by an increase in solar and wind from 0.2% in 2000 to a record 13.4% in 2023.

“Solar is leading the energy revolution,” said the report. “It was the fastest-growing source of electricity generation for the 19th year in a row, and surpassed wind to become the largest source of new electricity for the second year running.”

China was the main contributor to solar growth in 2023, accounting for 51%. Other major contributors were the EU (12%) and the U.S. (11%). Together the four solar growth economies, China, EU, the U.S., and Brazil, accounted for 81% solar growth in 2023.

Solar reached a 5.5% share of the global electricity mix, reaching 1,631 TWh, rising from 4.6% in 2022.

“Despite reaching new record highs, the absolute growth in wind and solar (+513 TWh) was below expectations and slightly smaller than in 2022 (+517 TWh). This was mainly due to lower-than-expected wind growth, which was 18% lower compared to the 249 TWh increase in 2022,” said Ember.

Demand for electricity grew by 637 TWh globally in 2023, rising 2.2%, or the equivalent of adding the entire electricity demand of Canada to the total. This brought global electricity demand to a record 29,471 TWh. The increase in demand in 2023 was slightly lower than the average annual increase over the previous decade of 2.5%.

Solar and wind met most of the increased electricity demand globally, adding 513 TWh of generation, or about 82% of new demand.

“Despite their lower-than-expected growth, solar and wind were the powerhouses of newly added clean electricity,” said the report. “In aggregate, all other clean electricity sources fell – small rises in bioenergy and nuclear were not enough to counter the large fall in hydro generation caused by extensive droughts. Together, all clean sources met 79% of the increase in electricity demand, creating a shortfall that was met by fossil generation.”

The unprecedented growth of solar energy is leading the charge toward a carbon-free energy system, said Ember. In the decade of 2000 to 2010 cumulative global capacity doubled every two years, then from 2010 to 2023 the rate slowed to doubling every three years. The International Energy Agency (IEA) said that if solar deployment continues along an arc of doubling every 3.8 years from 2023 to 2030, the world will be on-pace for its Net Zero Economy scenario.

“Solar capacity has boomed due to steep declines in costs, supportive policy environments, technology efficiency improvements, and increased manufacturing capability,” said Ember. “A key to the rapid rise is Wright’s law of technology learning curves, whereby the technology gets cheaper as it is deployed more and it is deployed more as it gets cheaper.”

Combined with nuclear, the world generated about 40% of its electricity from low-carbon sources in 2023. Ember said this has resulted in CO2 intensity of global power generation falling 12% lower than its peak in 2007.

However, despite the average emissions per unit of energy generated decreasing in 2023, carbon emissions are higher than ever. Absolute fossil fuel generation increased 0.8% over the year, and global emissions increased by 1%, reaching 14,153 million tons of CO2 emitted by electricity generation.

“2023 came very close to becoming the first year of a new era of falling power sector emissions,” said Ember. “As clean electricity growth continues, we have growing confidence that in 2024, it will rise above electricity demand and lead to a fall in emissions.”

Clean energy capacity growth was already large enough to deliver a decline in emissions 2023, but a record fall in hydropower generation due to droughts prevented that. Ember said that 2023 likely marked the peak of power sector emissions.

“A signal is emerging from the noise of year-on-year variability: the world is at the peak, and about to enter a new era of falling power sector emissions,” said Ember.

From pv magazine Global

A group of researchers from the University of Cantabria in Spain has conducted a pilot project for a self-sufficient home that runs exclusively on photovoltaics, batteries, and hydrogen storage.

“This plant combines PV panels and hydrogen (PVHyP) as a method of seasonal energy storage, achieving the ambitious target of accomplishing an electrically self-sufficient social housing unit throughout the year,” the group said. “To achieve this goal, a tailor-made energy management strategy (EMS) has been developed based on the state of charge of the battery pack and the energy flow within the PVHyP, ensuring that the electrical consumption of the home is always covered either through PV panels, fuel cell or battery pack.”

For their simulation, the scientists collected data from January 2022 to December 2023 for an 80 m2 social home that is located in Novales, a small village in northern Spain. Electricity bills from the years before the renewable electrification of the house showed that it consumed 2,513 kWh/year with an average daily consumption of 6.88 kWh. The average consumption in the winter and fall was over 7.3 kWh, and in summer, 5.88 kWh/day.

With these data, the scientists moved to size the energy system using software optimization and market analysis. Finally, they settled on 20 solar panels with a power of 40 W each placed on the roof, as well as four 2.4 kWh batteries. The rest of the plant was installed in a shed in the neighboring plot. That included a 35 L water tank that used tap water after purification for electrolysis and a 600 L hydrogen storage tank at 300 bar.

With the proposed system configuration, the PV panels first must supply the house load. The excess generation will then charge the battery, and once that is full, it is stored in a high-pressure storage tank in the form of hydrogen generated by an electrolyzer.

“When the solar irradiation is insufficient to cover the demand of the house, the batteries supply the necessary energy to the dwelling,” explained the academics. “If the batteries are discharged, the fuel cell generates electricity to charge the batteries from the stored hydrogen. As far as possible, the hydrogen stored in the buffer is used first to avoid the compression stage, thus increasing energy efficiency. The system and the house are connected to the grid on a self-consumption basis to sell back to the grid all the excess energy.”

According to the research group, the house demonstrated self-sufficiency, and its LCOE decreased from €0.86($0.92)/kWh to €0.34 /kWh, and the tenants saved €1,170 annually. “Almost 15,200 kWh have been saved from fossil fuels, which corresponds to approximately 2,260 kg of CO2,” emphasized the researchers.

They presented their findings in the study “Sustainable and self-sufficient social home through a combined PV‑hydrogen pilot,” published in Applied Energy.

Global actions, or inactions, are likely to lead to a rise in the average planetary temperature by more than 1.5°C due to escalating carbon dioxide levels. This potential rise has led researchers to examine the consequences using the Representative Concentration Pathway 4.5 Scenario, which predicts a 4.5°C rise. Many scientists warn that such warming could present significant global challenges.

In response to these findings, a team from the University of Michigan projects that climate change induced warming could increase the value of residential rooftop solar by between 19% and 25%. This expected rise in value is primarily attributed to increased demand for on-site electricity, complemented by a slight boost from enhanced solar electricity generation due to fewer cloudy days anticipated in the future.

The logic behind the first factor is simple: higher temperatures will necessitate increased use of air conditioning, leading to greater electricity consumption. As a result, buildings can derive more value from the solar power generated on their roofs by utilizing it immediately. This direct usage reduces reliance on net metering and diminishes dependency on distribution and transmission lines.

The study estimates that climate change could increase total household cooling energy by 40% to 100% in cities across various U.S. cities. The impact, however, varies by location; Miami experienced the most significant increase, while Minneapolis, situated much farther north, saw a slight decrease in the financial benefits of rooftop solar for households, specifically in terms of cooling costs. Among the 17 cities analyzed, Minneapolis was the only one to report a reduction in electricity consumption, due to its increasingly temperate weather.

Numerically, the analysis indicates that the electricity required for cooling these locations, measured in kilowatt-hours per year per square meter, will increase from 5, 11 and 24 kWh/m2 in cold, mild, and hot cities to 9, 16 and 31 kWh/m2, respectively, by the end of the century.

A second layer of analysis examined the potential electricity generation by solar panels under future weather conditions, revealing mixed results. Rising temperatures are expected to reduce solar power efficiency, thus decreasing their output. Conversely, the models suggest fewer clouds on average, which would boost generation.

Weather effects, which vary regionally, significantly impact solar output. For example, persistent high pressure in the upper atmosphere could drive solar irradiance up to 30% above normal, setting new records for solar generation and temperature in North America as seen in mid-February 2024.

The research team indicated that these two variables, when considered across all 17 cities, essentially neutralize each other.

Additional considerations for the value of residential rooftop solar in times of climate complexity include enhancing local resiliency and reducing the need for costly upgrades to distribution and transmission power grid infrastructure.

The U.S. Department of Energy’s National Renewable Energy Laboratory (NREL) has updated its Best Research-Cell Efficiency Chart with the inclusion of a new cell category – Hybrid Tandems.

“This category collects record tandem cells with layers composed of two different PV materials. Some subcategories of Hybrid Tandems (Perovskite/Si and Perovskite/CIGS) were already present in the previous format under ‘Emerging PV,’ whereas others (III-V/Si and Perovskite/organic) are new,” the research institute said in a statement. “All of these subcategories have been moved into the new Hybrid Tandems category—with the exception of perovskite/perovskite tandems, which are listed under Emerging PV.”

The NREL stressed that all these changes are now reflected in the interactive chart. The tool highlights the highest confirmed conversion efficiencies of research cells for a range of PV technologies.

“Everything up to the end of 2023 is included,” a spokesperson from the research institute recently told pv magazine, noting the chart also includes important results achieved in the first quarter of this year.

The chart now includes the 33.9% world record efficiency achieved in November by Chinese manufacturer Longi for a perovskite-silicon tandem solar cell and the 27.09% efficiency achieved by the same company for a heterojunction back contact solar cell. Furthermore, it comprises the 23.64% efficiency achieved in March by U.S.-based thin-film module maker First Solar for a solar cell based on copper, indium, gallium and diselenide (CIGS) technology.

The U.S. power grid in use today was built in the 1960s and 70s and is hard pressed to handle the extreme weather events caused by climate change, let alone the renewable energy needed to meet energy goals.

According to the U.S. Department of Energy, 70% of transmission lines are over 25 years old and approaching the end of their typical lifecycle. Grid upgrades that deploy modern grid technologies are sorely needed, and federal funding is available through the Grid Resilience and Innovation Partnership (GRIP) program, which recently closed applications for up to $2.7 billion in DOE grant funding under a second round.

Grid modernization has been underway in some states more than others, and the North Carolina Clean Energy Technology Center recently released The 50 States of Grid Modernization: Q1 2024 Quarterly Report, which looks at legislative and regulatory action related to smart grid and advanced metering infrastructure, utility business model reform, regulatory reform, utility rate reform, energy storage, microgrids, and demand response.

In Q1 2024, according to the report, 49 states plus DC and Puerto Rico took a total of 567 policy and deployment actions, the most common related to policies (133), financial incentives (108), and utility business model and rate reform (93).

Five top policy developments

Maryland: Lawmakers passed the Distributed Renewable Integration and Vehicle Electrification (DRIVE) Act in Maryland that directs the Public Service Commission to develop a program for utilities to establish virtual power plant (VPP) pilots to compensate owners and aggregators of distributed energy resources for distribution system support services.

Massachusetts: Eversource, National Grid and Unitil filed final electric sector modernization plans in January 2024. The plans include a variety of programs and investments, such as VPP programs, advanced distribution management system and distributed energy resource management system investments, resilience upgrades, heat pump integration, and non-wires alternative

Connecticut: The Connecticut Public Utilities Regulatory Authority (PURA) issued a set guidelines for utilities’ advanced metering infrastructure plans, including a directive to include advanced time-of-use rates and to use Green Button Connect functionality. Later in the quarter, PURA filed a straw proposal on performance incentive mechanisms (PIMs), which includes four PIMs based on non-wires solutions, equitable reliability, distributed energy resource interconnection, and avoided service terminations.

Colorado: The Colorado Public Utilities Commission (PUC) approved guidelines and directives for VPP implementation in Xcel Energy’s service territory.

Maine: The Governor’s Energy Office in Maine released its final long-duration energy storage (LDES) study that identifies policy considerations and actions for the state to support LDES. The PUC also released a study that examines utility control or ownership of energy storage, finding that utility ownership of storage should only be allowed under certain circumstances.

Top trends

Grid-enhancing technologies can boost the use of any existing transmission system, according to a study by The Brattle Group, which looked specifically at advanced power flow control, topology optimization and dynamic line ratings. The NC State report said use of grid-enhancing technologies (GETs) is a notable trend and noted the following actions:

• Virginia lawmakers enacted a bill requiring utility integrated resource plans to include a comprehensive assessment of the application of GETs and advanced conductors. In
• Maine legislators enacted a bill requiring the PUC to conduct a review of available GETs that large investor-owned utilities may use to reduce investment needs in grid infrastructure.
• Minnesota lawmakers introduced bills requiring utilities to file plans regarding the implementation of GETs to prevent grid congestion at the transmission level.
• New York legislators introduced bills that would allow the Department of Public Service to approve requests from distribution companies to develop GETs.

Other states considering legislation initiating studies on GETs include Connecticut and New Hampshire.

Virtual power plants

VPPs give grid operators a utility-grade alternative to new generation and system buildout by automating efficiency, capacity support and offering non-wire alternatives, according to Jigar Shah, director of the U.S. Department of Energy Loan Programs Office. “By deploying grid assets more efficiently, an aggregation of distributed resources lowers the cost of power for everybody, especially VPP participants,” Shah said in an article in pv magazine USA.

According to the NC State report, a state policymakers and regulators are taking steps to develop frameworks for VPPs in their states:

• Pennsylvania regulators issued an advanced notice of proposed rulemaking seeking input on VPPs as a potential resource for the state.
• Maryland lawmakers passed a bill directing the Public Service Commission to develop a program for utilities to establish VPP pilots, with each investor-owned utility required to propose a pilot or temporary tariff by July 1, 2025.
• Colorado PUC issued a decision outlining rules for VPP pilots and acquisition.
• California and Hawaii regulators are also advancing expansive programs to promote VPPs.

Microgrids

Microgrids are groups of distributed energy resources, such as solar modules on a home, connected to a battery system, that can disconnect from the grid and operate independently during a power outage. The U.S. Department of Energy has a vision that 30% to 50% of electricity generation will come from distributed resources by 2035, with microgrids playing a key role in the transition.

The NC State report found that a growing number of states are evaluating the potential for microgrids to provide resilience or other benefits in their states.

• Colorado Energy Office is currently developing a microgrid roadmap, which will examine how microgrids can improve grid resilience and reliability in the state.
• New Hampshire lawmakers recently passed a bill requiring the state’s Department of Energy to study the potential benefits, risks and other factors of developing a microgrid framework.
• Rhode Island PUC issued request for proposal for a study related to microgrid program design.
• Puerto Rico Energy is examining revisions to its existing microgrid revisions.
• Arizona regulators issued a decision prohibiting Arizona Public Service from providing microgrid services.

Lawmakers in California, Iowa, New Jersey, and New York also considered legislation related to microgrid studies during the quarter.

Researchers from the University of Michigan have found that climate change will increase the future value of residential rooftop solar panels across the United States by up to 20% by the end of the century.

In “Climate change will impact the value and optimal adoption of residential rooftop solar,” which was recently published in Nature Climate Change, the researchers quantified the effects of climate change on rooftop solar value and optimal capacity. They analyzed data from 2,000 households across 17 US cities, estimating air-conditioning demand and solar panel performance under future climates.

Mai Shi, the study’s lead author, told pv magazine that this is the first study to quantify how climate change will affect the value of rooftop PV for households in the future.

“Value here means economic value – how much does a household save on its electricity bill when it installs rooftop solar,” Shi explained. “Our analysis captures how climate change will affect household electricity demand through increased cooling demand and household rooftop PV generation.”

The researchers said that rooftop solar value will increase by between 5% and 15% across a wide range of US cities under moderate climate change by the mid-century, and then by up to 20% by the end of the century.  Greater increased value was analyzed in homes with larger cooling intensities and cities with increasing radiation and higher power retail prices.

Across the 17 cities, Miami and Orlando are expected to see the strongest increase in solar value. Shi said that in these cities, climate change is expected to increase solar radiation, which in turn will favor more rooftop PV generation, while increases in air temperatures will lead to more household electricity demand.

“Given the average 25-year lifespan of a rooftop solar installation, a system built today will nearly experience 2050 weather. Therefore, it’s important for households to think of future value when building solar,” Shi said. “If households do so, our findings indicate they would see even greater value from solar, and might decide to build more.”

From pv magazine Global

A group of researchers from the University of Cantabria in Spain has conducted a pilot project for a self-sufficient home that runs exclusively on photovoltaics, batteries, and hydrogen storage.

“This plant combines PV panels and hydrogen (PVHyP) as a method of seasonal energy storage, achieving the ambitious target of accomplishing an electrically self-sufficient social housing unit throughout the year,” the group said. “To achieve this goal, a tailor-made energy management strategy (EMS) has been developed based on the state of charge of the battery pack and the energy flow within the PVHyP, ensuring that the electrical consumption of the home is always covered either through PV panels, fuel cell or battery pack.”

For their simulation, the scientists collected data from January 2022 to December 2023 for an 80 m2 social home that is located in Novales, a small village in northern Spain. Electricity bills from the years before the renewable electrification of the house showed that it consumed 2,513 kWh/year with an average daily consumption of 6.88 kWh. The average consumption in the winter and fall was over 7.3 kWh, and in summer, 5.88 kWh/day.

With these data, the scientists moved to size the energy system using software optimization and market analysis. Finally, they settled on 20 solar panels with a power of 40 W each placed on the roof, as well as four 2.4 kWh batteries. The rest of the plant was installed in a shed in the neighboring plot. That included a 35 L water tank that used tap water after purification for electrolysis and a 600 L hydrogen storage tank at 300 bar.

With the proposed system configuration, the PV panels first must supply the house load. The excess generation will then charge the battery, and once that is full, it is stored in a high-pressure storage tank in the form of hydrogen generated by an electrolyzer.

“When the solar irradiation is insufficient to cover the demand of the house, the batteries supply the necessary energy to the dwelling,” explained the academics. “If the batteries are discharged, the fuel cell generates electricity to charge the batteries from the stored hydrogen. As far as possible, the hydrogen stored in the buffer is used first to avoid the compression stage, thus increasing energy efficiency. The system and the house are connected to the grid on a self-consumption basis to sell back to the grid all the excess energy.”

According to the research group, the house demonstrated self-sufficiency, and its LCOE was cut by about one-third and the tenants saved $1,251 annually. “Almost 15,200 kWh have been saved from fossil fuels, which corresponds to approximately 2,260 kg of CO2,” emphasized the researchers.

They presented their findings in the study “Sustainable and self-sufficient social home through a combined PV‑hydrogen pilot,” published in Applied Energy.

Over 10 million homes are located within one mile of the 8,000+ large-scale solar (LSS) projects, as reported by Energy Markets & Policy (EMP) at the Lawrence Berkeley National Laboratory. This number is expected to grow significantly, despite efforts by certain groups to spread falsehoods and hinder progress. Solar power does remain the most popular form of electricity nationwide, despite its popularity declining in more conservative and rural areas as a result of targeted attacks.

To better understand the perceptions of those living near solar power facilities, the EMP team, in collaboration with the University of Michigan, conducted a comprehensive, 12-page survey that explored 49 different aspects of living near LSS projects.

Data solicited from 4,974 households was published in ‘Perception of Large-Scale Solar Project Neighbors: Results from a National Survey’. The group shared the responses from 984 households located within three miles of 380 unique LSS projects, with 71% of these households located within one mile of the projects.

According to the EMP study, neighbor attitudes remained fairly consistent until projects surpassed 100 megawatts, at which point the sentiment shifted dramatically, displaying a 12 to 1 ratio of negative to positive responses. This strong opposition was closely linked to concerns about the impact on local aesthetics, overall quality of life, and perceptions of unfairness in the project planning process.

Notably, only 20% of those surveyed were aware of the projects before construction began, and about one-third discovered the projects’ existence only upon receiving the survey. Those who see large solar installations on a daily basis were significantly more likely to express negative attitudes toward these projects.

When asked about expanding LSS projects and other types of energy infrastructure, respondents showed the strongest support for rooftop solar, with less than 10% opposition. Support for new LSS projects ranked second, followed by wind energy, gas plants, pipelines, wells, and nuclear energy, in that order.

Interestingly, if a solar power project must be built, agrivoltaic projects (which integrate agriculture with photovoltaic systems to maximize land use) received the highest approval ratings, with less than 10% expressing a negative view, and 50% being positive or very positive.

The results showed that 85% of these neighbors held a positive or neutral view of their local solar power projects, 11% viewed them negatively, and 4% had a very negative perception. Attitudes were slightly less favorable among those living within a quarter mile of a facility.

Overall, support for constructing additional solar facilities was strong, with 42% in favor and only 18% opposed. However, attitudes shifted significantly as project sizes increased. Research from upstate New York echoed these findings, showing a change in perception when projects exceeded 50 acres.

The NC Clean Energy Technology Center (NCCETC) released its Q1 2024 edition of its 50 States of Solar report, which looks at changes in policies on net metering, distributed solar valuation, community solar, residential fixed charges and more.

NCCETC is a public service center administered by the College of Engineering at North Carolina State University, with a mission to advance a sustainable energy economy by educating, demonstrating and providing support for clean energy technologies, practices, and policies. The Center is known for its DSIRE database that tracks incentives in all 50 states for renewable energy and energy efficiencies.

The Q1 2024 report finds that 43 states plus Washington DC and Puerto Rico took a total of 163 actions related to distributed solar policy and rate design. The map above summarizes state actions related to compensation for distributed generation (DG), rate design, and solar ownership. Of the 163 actions cataloged, the report authors note that the most common were related to DG compensation rules (56), followed by residential fixed charge and minimum bill increases (42), and community solar (37).

Trends spotted in the report include legislation to enable community solar, net metering reform considered by new states and states clarifying time of use rates for net metering customers.

Community solar is a way for homeowners, businesses and other organizations to invest in the benefits of clean energy when they have unsuitable conditions for rooftop or on-site ground-mounted installations. While installations of community solar contracted in 2022, Wood Mackenzie forecasts the U.S. community solar market to grow 118% over the next five years, with at least 6 GW expected to come online in existing markets between 2023 to 2027.

The NCCETC report finds that an increasing number of states are considering community solar legislation. For example, Pennsylvania recently passed a bill that would establish a community solar program, and similar bills are pending in Michigan, Ohio, and Wisconsin. Legislators in Missouri are taking a slightly different approach with bills introduced that direct electric suppliers to create three-year community solar pilot programs, and similarly, West Virginia lawmakers intend to create a pilot program. Alaska, Georgia and Iowa also have community solar bills pending.

It comes as no surprise that more states are considering changes to their net metering rules, following in the footsteps of California’s NEM 3.0, which has become the solar policy story of the year. In Delaware, for example, lawmakers  approved legislation to conduct a net metering cost-benefit study, and regulators in Wisconsin are also conducting a value of solar study. In Kentucky, Duke Energy wants to implement a net metering successor tariff that would involve real-time netting and reduced compensation for exported energy for new customer-generators. A Washington utility is preemptively amending net metering tariff language to close the tariff upon reaching an aggregate cap.

States and utilities are increasingly moving to time-of-use rates because they vary the cost of electricity according to when it’s used. For example, a solar-powered home generates electricity during the day, when rates are cheaper, but the household may use the most electricity in the evening, when it is more expensive. Examples of states taking steps to clarify how net metering is conducted on a time-of-use rate basis include Kansas, Maryland and North Carolina.

Maryland’s Public Service Commission recently directed its rate design working group to examine utility tariffs and propose any needed charges for net-metered customers under time-of-use rates. In South Carolina pending legislation would increase the state’s net metering system size limit, but only for customer-generators on time-of-use rates.

The Q1 report noted top solar policy developments, which are both good and bad for electric customers generating their own solar electricity. In Massachusetts, which has especially solar-friendly policies, regulators voted to allow electric customers to transfer credits across utilities. Plus some systems are exempt from the state’s net metering caps.

Virginia, historically a coal state, voted in 2020 to close all the state’s coal power plants by 2024. This is part of the forward-looking Virginia Clean Economy Act, which requires the state’s utilities to switch to 100% clean energy by 2050, while also adding 16 GW of solar and onshore wind, 3 GW of energy storage. Now legislators have gone a few steps further by passing bills that increase the capacity of Dominion Energy’s community solar program and direct regulators to set up a community solar program for Appalachian Power customers. Other bills under consideration in Virginia would expand solar leasing and power purchase agreements.

West Virginia, another former coal state, adopted net metering reforms that sets export credit rates at 8.91 to 9.343 cents per kWh in Monongahela Power & Potomac Edison’s rate case.

The Arizona Corporation Commission (ACC) approved a request from major utility Arizona Public Service to raise electricity rates for all customers, assess fixed charges, and to single out those who have invested in rooftop solar with the largest of such charges. The approved charge equals $0.242 per kW of on-site generation for customers on standard time-of-use rates and $0.215 per kW for customers on the time-of-use rate including a demand charge. The report notes that several participants have filed petitions for rehearing to overturn the grid access charge.

To produce the quarterly 50 states report, NCCETC reports that it looks at important proposed and adopted policy changes affecting solar customer-generators of investor-owned utilities and large publicly owned or nonprofit utilities serving at least 100,000 customers.

From pv magazine global

Researchers developed a novel vapor deposition method for all-inorganic perovskite absorbers using continuous flash sublimation (CFS).

They described the new technique as a non-batch process that solves two problems associated with the use of established vapor processing in perovskite material manufacturing – the slow speed of deposition and the non-continuous nature of batch processing.

“Our deposition approach allows for the continuous deposition of a fully absorbing perovskite material within less than five minutes,” corresponding author Tobias Abzieher from Swift Solar, a U.S.-based perovskite PV startup, told pv magazine. “Solar cells prepared with these materials also outperform previously realized efficiencies of vapor processed inorganic perovskite solar cells significantly.”

The researchers said that they are pursuing vapor processing because of its potential for high yield, high-quality and high reproducibility processing, and its potential to eliminate the use of hazardous solvents. Furthermore, it is seen as simplifying the scaling up to larger device areas. In addition, its performance on rough surfaces makes it attractive for perovskite-based tandem applications.

“The limited throughput of vapor processes for the deposition of perovskite materials remains the number one bottleneck for a swift commercialization. Researching alternative deposition strategies is therefore key,” David Moore, a researcher from the US Department of Energy’s National Renewable Energy Laboratory (NREL) and co-corresponding author told pv magazine.

The scientists fabricated a variety of “high-quality” cesium lead halide (CsPb(I_xBr_1−x)₃) thin films in a prototype system to test the versatility of the CFS approach, noting that the process was able to produce thin film compositions “across the entire bromine/iodine space maintaining the composition of the source materials”.

They noted that the CFS approach enabled the reduction of the time required to deposit a “fully absorbing layer to less than 5 minutes” in a continuous deposition process.

The CFS-derived films were made into working solar cell devices. The study’s champion solar cells achieved power conversion efficiencies as high as 14.9%, open-circuit voltage of 1.17 V, fill factor of 76.0%, and short-circuit current densities of 16.8 mA cm−2. The forward scan direction values were 10.3%, 1.12 V, 55.1%, and 16.7 mA cm−2, respectively.

The researchers describe the source material, a mechano-chemically synthesized powder, and how it is prepared by mixing individual precursor materials, cesium and lead salts into a stochiometric powder. They said it was flashed at high temperatures to overcome the differences in deposition characteristics of the individual precursor materials.

The powder was filled into a reservoir connected to a vibratory feeder, which in turn was connected to an AC signal. After moving along the vibratory feeder, the powder falls into a preheated tantalum evaporation boat kept at a temperature “significantly above” the highest sublimation temperature of the individual inorganic salts, typically in the range of 700 C. “Inside the evaporation boat, the powder constituents instantaneously sublime, leave the evaporation source, to finally condense on a substrate situated above the evaporation boat,” explained the team.

An annealing step at temperatures between 330 C and 380 C for 0.5 min to 1 min was implemented after the CFS step to “improve thin-film quality and to ensure stabilization of the correct photoactive perovskite phase”. The details are described in “Continuous flash sublimation of inorganic halide perovskites: overcoming rate and continuity limitations of vapor deposition,” published in the Journal of Materials Chemistry A.

The team concluded that the work is a critical step toward fast and continuous processing of perovskite materials, which is “highly suitable for the fast deposition of thin films whose individual constituents have significant differences in sublimation characteristics.”

“I can imagine that a process like this could be used for the industrial fabrication of perovskites. Throughput is one of the number one bottlenecks of vapor processing of perovskites, so developing novel approaches that overcome this limitation are crucial,” Abzieher said, when asked about technology transfer potential.

Looking ahead at research activity, David Moore said that NREL, for example, is looking into the use of the CFS method for other hard-to-deposit material classes, as well as investigating using this method with other types of perovskite materials, such as hybrid materials containing organic and inorganic precursor materials.

Renewables and storage interconnection backlog grew about 30% last year  The wait for transmission interconnection studies constitutes a “major bottleneck” for solar, storage and wind projects, which accounted for over 95% of all active capacity awaiting studies at the end of 2023, Lawrence Berkeley National Laboratory has reported.

S-5! unveils new mounting systems for rooftop solar  S-5!, a supplier of mounting systems, plans to release two new mounting components for rooftop PV systems, including a new mount that allows for module-level power electronics to be attached directly to solar panel frames.

A guide to help homeowners understand how to go solar Researchers at Pacific Northwest National Laboratory published an open access guide to rooftop solar and battery energy storage that covers costs, incentives, policies and more.

New quantum solar cell material promises external quantum efficiency of 190% The new material consists of an heterostructure combining germanium, selenium, and tin sulfide, which also integrates atoms of zerovalent copper. It features an average photovoltaic absorption over 80% and could help photovoltaic cells break the Shockley-Queisser efficiency limit, according to its creators.

California’s electricity multi-crisis can be aided by virtual power plants By operating distributed resources like solar, batteries and demand response devices in concert, California ratepayers could be paid $500 to $1,000 per year while improving resource adequacy.

California Supreme Court to review rooftop solar net metering The state’s highest court granted review to a lawsuit challenging a “regressive” rooftop solar policy called NEM 3.0.