From pv magazine Global

An international research team has developed a particle swarm optimization (PSO) algorithm based on quantum computing for real-time maximum power point tracking (MPPT) implementation in PV systems.

The scientists explained that the quantum version of the PSO algorithm capitalizes on the high speed of quantum computing and reduces the interval of random numbers in subsequent stages to avoid premature convergence. “A detailed implementation of the quantum aspect of the solution is provided using qubit states instead of classic particles and performing qubit spins using the y-axis rotation gates to perform the moves on the qubit states to search for the optimal solution,” they explained.

In quantum computing, a qubit or quantum bit is a basic unit of quantum information. It is the quantum mechanical analog of a bit in classical computing based on binary digits.

The proposed quantum particle swarm optimization (QPSO) algorithm is based on Schrödinger’s equation  – a differential equation that defines the behavior of wavefunctions in quantum mechanics.

“Simulating the behavior of human intelligence, rather than that of a flock of birds or a school of fish, necessitates capturing the thought processes of a complex social organism, which cannot be adequately described by a linear evolution equation,” the researchers said, seeking to describe the working principle of the algorithm. “It is believed that human thinking is as uncertain as a particle with quantum behaviors.”

The group tested the performance of the algorithm through Matlab Simulink software in a simulated PV array relying on four 213 W solar modules. It found the QPSO algorithm shows a strong ability to maintain performance close to that of conventional PSO across different environmental conditions. “It performs well in power optimization and maintaining system activity, as indicated by the power output and duty cycle values under both optimal and challenging conditions,” the academics added, noting that the proposed algorithm also requires “more prominent” computational demands.

They also found that, although the power achieved by the conventional PSO algorithm was approximately 0.15% higher than that attained by the QPSO algorithm under the same conditions, the QPSO was able to beat the conventional PSO in more challenging conditions.

“Specifically, the quantum algorithm generates 3.33% more power in higher temperature tests and 0.89% more power in partial shading tests,” they emphasized. “Additionally, the quantum algorithm displays lower duty cycles, with a reduction of 3.9% in normal operating conditions, 0.162% in high-temperature tests, and 0.54% in partial shading tests.”

The new algorithm was described in the study “Quantum maximum power point tracking (QMPPT) for optimal solar energy extraction,” published in Systems and Soft Computing. The research group included scientists from Algeria’s École Nationale Polytechnique and its École Nationale Supérieure de Technologies, Canada’s Université du Québec à Trois-Rivières, and the Norwegian Research Centre.

“Despite the classical algorithm’s marginal advantage in power output under normal conditions, the quantum algorithm illustrates superior performance across all other metrics, achieving higher power values and consistently lower duty cycle records, indicating more excellent general efficiency,” the scientists concluded. “Future work could explore adaptive algorithms that dynamically adjust to changing environmental conditions, enhancing efficiency and reliability.”

From pv magazine Global

A group of researchers at the Edith Cowan University in Australia has proposed a new methodology to determine the optimal size of large inverter-connected energy storage systems (ESSs) planned for emergency under-frequency response.

“Delivering the necessary response with minimal ESS capacity is advantageous for power system planning and operating a fleet of partially discharged ESS units,” the scientists said, noting that the proposed solution is also feasible at low costs. “Characteristics such as rise time, overshoot, and settling time of active power response can be controlled by adjusting specific parameters.”

In the paper “Optimizing grid-forming inverters to prevent under-frequency load shedding with minimal energy storage,” published in the Journal of Energy Storage, the researchers explained that ESS active power capacity can be used to minimize under-frequency load shedding (UFLS) schemes, which are generally activated during low-frequency events, shedding predetermined loads to prevent further frequency drops.

“Since UFLS events are rare, some transmission system operators do not require maintaining headroom to cater for large disturbances,” the research team said. “Thus, using ESS for emergency under-frequency response is a cost-effective option. Additionally, delivering the necessary response with minimal ESS capacity is advantageous for power system planning and operating a fleet of partially discharged ESS units.”

The academics also explained that the novelty of their work consisted of determining a battery’s minimum power rating for both virtual synchronous generators (VSGs) and droop control-based grid-forming (GFM) inverters. The ESS size, they specified, must be calculated to maintain the frequency within the standard operating range.

“The ESS size is optimized to prevent under-frequency load shedding following a trip of a large generator by maintaining frequency within frequency operating standard (FoS),” they also emphasized. “The calculation of control parameters and ESS size determination considers the multi-step duration and thresholds provided by the FoS. UFLS protection settings are designed based on the FoS and sizing ESS to achieve a fixed frequency will not provide the optimum ESS size.”

The proposed approach is based on a Hill climbing algorithm, which is a classic optimization technique in artificial intelligence that takes inspiration from climbing to the peak of a mountain. It works by increasing the elevation value to find the peak of the mountain or the best solution to a given problem. It terminates when it reaches a peak value where no neighbor has a higher value.

The group investigated a case study of a power system implemented via DIgSilent PowerFactory software.

The simulation showed that for GFM inverters, a decrease in the active power droop coefficient increases the active power output. This increase, however, is limited by current inverters’ constraints. As a result, the scientists suggest maintaining the active power droop coefficient at a value that can prevent instability resulting from inverters’ limitations while maximizing the active power output.

As for VSGs, they suggested maintaining the acceleration constant, which can reportedly strike a balance between the rate of change of frequency (RoCoF) and power oscillations. They noted that the acceleration time constant of the VSG controller is proportional to inertia and increasing it enhances inertia.

“For the case considered in this study, the minimum energy storage power rating for the virtual synchronous generator control is 85 MVA, while for droop control, the minimum storage capacity is 89 MVA,” the scientists concluded. “The results of this study should be helpful for power system planners to better harness the capabilities of energy storage systems.”

From pv magazine Global

Chinese solar module maker Trina Solar is actively trying to determine whether other manufacturers are currently violating some of its patents for TOPCon solar cell technology.

“In Trina’s opinion, it is necessary to create a fair ecosystem in which intellectual protection plays an important role,” Álvaro García-Maltrás, Trina Solar’s general director for Latin America and the Caribbean, told pv magazine. “What Trina finds difficult to accept is that other companies access this ecosystem illicitly or by avoiding investments. Our R&D investments exceed $3 billion.”

García-Maltrás has not identified any manufacturers that might be using its TOPCon patents. He did express confidence that the company could reach reasonable solutions through settlement agreements, rather than legal action.

“We don’t want to enter in any legal dispute,” he noted. “But we would like those companies that identify that they have a void in their internal management systems, they look for a way to fill it, either with their own patents or by approaching the owners of the used patents to talk about licensing agreements.”

One of the patents that Trina Solar is investigating concerns the number of busbars and their width in TOPCon panels.

“TOPCon solar panels can have a varied number of busbars, as well as widths,” García-Maltras explained. “Finding the optimal balance between the number of busbars and their width is crucial. Our patented technology clarifies the ratio between the number of busbars and their width, optimizing the output efficiency of solar cell modules. This also maximizes the conversion of solar energy into electrical energy, while ensuring the robustness and longevity of the solution to withstand years of operation.”

García-Maltrás also said that the production of TOPCon panels requires a series of patents.

“I think that no manufacturer has developed 100% of the patents it uses in production,” he said. “There are agreements between manufacturers that want to cooperate and want to protect investments in R&D. This is the kind of industrial environment we want to support.”

Trina’s recent move follows First Solar‘s announcement last week that it is evaluating potential infringements of its TOPCon patents. First Solar secured the patents through its acquisition of TetraSun in 2013.

Bill Mulligan, CEO of Singapore-based IBC solar module maker Maxeon, also told pv magazine in June that the company is prepared to enforce intellectual property rights with all existing and new back-contact (BC) competitors that are allegedly using its technologies.

In February, Trina Solar and its South Korean rival, Hanwha Qcells, reached a settlement agreement on a patent dispute that the Chinese module maker launched in January. In a joint statement, the two companies said they had reached a patent licensing and transfer agreement over their intellectual property.

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.

ReCreate, a joint venture between the founders of U.S.-based Create Energy and EU-based Recom Technologies, announced in mid-June a plan to build a 5 GW solar module and cell manufacturing facility in Portland, Tennessee. Create Energy is the brainchild of Dean Solon, who previously grew Shoals Technologies Group from a Tennessee-based startup to a publicly listed PV BOS manufacturer in January 2021. Hamlet Tunyan is the CEO of Recom Technologies, a European module manufacturer.

pv magazine spoke with both solar entrepreneurs on the future factory at last month’s Intersolar 2024 in Munich, Germany.

“In the first quarter of 2025, we will have two module assembly lines operating at the factory, with up to 2 GW capacity,” Tunyan said. “We will then begin cell production within 18–24 months.” For the deployment of the cell lines, ReCreate will potentially acquire another building.

The company will initially source solar cells from Asia, excluding China. “We could even import cells from Korea,” Tunyan stated. “We have to meet increasing module demand in the United States,” Solon added. “Project developers are currently in trouble, and we want to provide them with reliable products.” Increased tariffs on solar modules imported from Southeast Asia threaten to limit their supply to the US downstream market. Southeast Asian manufacturers account for 80% of solar components in the US.

Solon also explained that the ReCreate modules produced at Create’s facilities will be part of a combined package from Create Solutions. This can include equipment EPCs require for their projects, such as transformers, switchgear, MBOS, BESS, and EVSE. “Create Energy along with Create Solutions, wholly owned subsidiaries of Create Holdings, are a one-stop-shop where you can source all the equipment and services needed for renewable energy projects,” Solon said.

The module production facility will initially produce TOPCon panels, although ReCreate may also consider adding heterojunction (HJT) or back contact (BC) products to its portfolio. “Wherever the module technology is going, that’s where we’re heading; we’ll always be on the leading edge,” Solon and Tunyan specified.

He also revealed that, in the future, ReCreate’s modules will be used in what they call “next-gen” PV systems. “Create’s vision is to provide solutions that navigate labor constraints and maximize system reliability at the lowest installed cost per kW,” Solon said. “This will include optimizing the interplay between modules, trackers, power stations, and other integrated systems.”

At his own venture, Create Energy, Solon is charging ahead with disrupting the energy storage and microgrid markets. NanoGrid, the company’s first product, will be the microgrid solution for a top-tier Japanese car manufacturer, extending to dealerships across North America. According to Solon, NanoGrid involves “canopy and rooftop solar, battery energy storage, and site-load monitoring tied to level 2 and level 3 EV charging solutions.”

In addition to starting Create Energy, Solon also anchored the formation of Neos Partners following the IPO and his departure from Shoals. Neos raised $830 million as a private equity fund that has invested in six companies to date, a very impressive track record for a fund that closed in spring of ’23. Solon refers to this collection of target companies as an “un-evil empire” providing transformers, switchgear, EPC, and engineering services. “Create’s clean-tech products are reimagining renewables beyond utility infrastructure to the power-starved EV, data center, and artificial intelligence (AI) markets,” said Solon.

As Solon revealed in Munich, ReCreate modules and cells are just the beginning. “Made in Tennessee” batteries seem to be in the works as well and the focus will be on providing complete EV, PV, and BESS solutions from Create Energy to the North American & EU Markets, supplying large-scale EPCs, renewable energy developers, and Commercial and Industrial (C&I).

From pv magazine Global

First Solar said it is investigating potential violations of the patents it owns for TOPCon solar cell technology.

“First Solar secured the US patent and related international counterparts through its acquisition of TetraSun, Inc. and has initiated an investigation of several c-Si solar manufacturers for potential infringement of its patents,” the company said in a statement. “The patents include issued patents in the United States, Canada, Mexico, China, Malaysia, Vietnam, Japan, and Australia, among other jurisdictions, with validities extending to 2030. It also includes pending patent applications in the European Union and Japan.”

The company has not identified the potential infringers or provided a timeline for the investigation.

“First Solar acquired TetraSun and its intellectual property portfolio in 2013. Prior to its acquisition, the California-based startup had pioneered proprietary cell architecture and manufacturing processes for large-format crystalline silicon wafers,” First Solar also said, without providing additional technical details. “If infringement is discovered, we intend to challenge the ability of potential infringers to legally manufacture, assemble, and sell infringing TOPCon technology by pursuing enforcement, licensing, and/or other measures to safeguard our rights.”

First Solar produced PV modules using TetraSun technology at its Malaysian factory until 2016, ending its production of crystalline silicon solar panels.

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.

From pv magazine Global

The international research group led by Professor Martin Green from the University of New South Wales (UNSW) in Australia has published Version 64 of the “solar cell efficiency tables” in Progress in Photovoltaics.

The scientists said they have added 19 new results to the new tables since December.

Strong progress was reported across the whole range of solar cell technologies including silicon, chalcogenide, organic and perovskite.

A major new result is the 27.3%-efficient n-type silicon heterojunction interdigitated-back-contact (HBC) solar cell unveiled by Chinese manufacturer Longi in late May. “The cell, establishing a new outright record for silicon, has both polarity contacts on the rear surface restricting loss by the absence of contacts on the front illuminated surface,” the paper reads. “An all-laser patterning process was used for the more complex rear surface patterning required for such devices.”

Another result is the 34.2% power conversion efficiency that Longi achieved for a perovskite-silicon tandem solar cell in April with an updated value of 34.6% obtained in May held in reserve and reported at June’s Shanghai New Energy Conference (SNEC).

The list also includes a 25.6%-efficient large-area n-type TOPCon cell fabricated by JA Solar, a 26.8%-efficient large-area n-type silicon cell fabricated by Longi, and the 24.9% efficiency that Singapore-based Maxeon reached for its IBC solar module.

Furthermore, the tables now include the 22.6% efficiency that US-based First Solar achieved for a 0.45 cm2 cadmium-telluride (CdTe) cell, as well as several other thin-film solar cells based on kesterite (CZTSSe) or copper, gallium, indium, and diselenide (CIGS). These include reaching the 15% efficiency milestone both for small-area CZTSSe cells made by the Chinese Academy of Science and a full-sized 0.8 m2 perovskite module made by Microquanta founded by former UNSW students.

In Version 63 of the tables, released in December, the researchers added 6 new results. The group has seen major improvements in all cell categories since 1993, when the tables were first published.

The research group includes scientists from the European Commission Joint Research Centre, Germany’s Fraunhofer Institute for Solar Energy Systems and the Institute for Solar Energy Research (ISFH), Japan’s National Institute of Advanced Industrial Science and Technology, and the US National Renewable Energy Laboratory.

From pv magazine Global

AEG, a power solutions company based in Germany, has launched new three-phase hybrid inverters for applications in high-voltage rooftop PV systems.

“The new AEG hybrid inverter with 15 kW works with the high current streams of the larger solar module types – where higher power goes hand in hand with higher currents,” a spokesperson from the company told pv magazine.

There are five versions of the new products, with power outputs ranging from 6 kW to 15 kW, and the maximum output current ranging from 8.7 A to 21.7 A.

The devices measure 460 mm x 496 mm x 221 mm and weigh 23 kg, and offer 3 maximum power point tracking (MPPT) channels. MPPT voltage ranges from 120 V and 850 V, while the maximum input current for MPPT is 16 A.

The inverter efficiency is 98.2% and the maximum input voltage for all devices is 1,000 V. Its European efficiency rating is 97.5% and the MPPT efficiency is 99.5%. The new product also features natural convection cooling and IP66-rated protection.

“The new inverter is designed to be a seamless match for the new AEG stackable battery, and for the existing AEG high voltage monobloc battery as well,” the spokesperson added. “The HV monobloc battery is preferred in some of our markets as it allows connection in parallel of up to 10 batteries reaching a total of 150 kWh and can be paired with a wide variety of hybrid inverter models.”

AEG is offering a 10-year warranty for the new inverter.

From pv magazine Global

Wood Mackenzie has released its PV module manufacturer rankings for 2023. The company said it evaluated 30 manufacturers on nine criteria: manufacturing experience, manufacturing capacity, vertical integration, capacity utilization rates, technology maturity, R&D, financial conditions, adherence to environmental social governance (ESG) and corporate social responsibility (CSR), and availability of third-party certifications.

JA Solar grabbed the top spot in the rankings with a score of 82.9, followed by Trina Solar with 81.7, JinkoSolar with 80.8, Canadian Solar with 78.5, and Longi and Risen sharing the fifth position with 78.0. The other six positions were taken by Tongwei with 77.6, Astronergy with 76.3,  Hanwha Qcells with 75.8, DMEGC with 74.1, Elite Solar with 71.4, and Boviet Solar with 71.2.

“Eight out of the 12 ranked module manufacturers are self-sufficient in cell capacity,” WoodMac said in a statement. “Tongwei and Risen are the only manufacturers in the ranking that are fully vertically integrated through the whole supply chain from polysilicon to module.”

The research firm also reveals that seven of the top 10 manufacturers could exceed 100 GW of annual module production capacity by 2027, with their combined cell capacity reaching 830 GW by the end of 2026. It also noted that all of the manufacturers continue to expand their capacity, despite massive overcapacity in the market.

“At the same time, manufacturers are focused on becoming more vertically integrated,” said Wood Mackenzie.

The list was scored via nine weighted criteria:

From pv magazine Global

Scientists from the Université de Sherbrooke in Canada have fabricated a prototype of a concentrator photovoltaic (CPV) module based on the so-called surface-mount technology (SMT) – a technique that is commonly used to mount electronic components to the surface of a printed circuit board (PCB).

The proposed SMT design used no wire bonding for cell emitter connection and is intended to increase heat dissipation in the CPV panel, which in turn reduces its operating temperature and increases its performance.

“The SMT, which uses a conductive solder paste for interconnection, has the advantage of being less expensive and faster for large-scale production, and SMT equipment takes up less space than wire-based wiring equipment,” they explained. “We have developed and employed the SMT process, which integrates assembly flexibility and enhanced alignment of solar cells, to assemble the solar cells larger than a millimeter in size.”

The 4-solar cell CPV module prototype uses a Fresnel lens to concentrate light onto cells soldered on a transparent glass PCB and protected by lamination layers. The emitter contacts are soldered through conductive solder joints to a glass PCB, which embeds metal tracks for the non-soldered areas. Transparent underfill fills the gap between the solar cell and the PCB to prevent reflections at the interfaces of the module’s bottom plate.

“Underfill fillets protect the sides of the solar cell to prevent short circuits and contribute to the thermomechanical stability of the assembly,” the research team stated. “The back face of the assembly is laminated with an EVA encapsulant and a Tedlar protective sheet to preserve the solar cells from the environment.”

The four cells used in the device are non-interconnected with each other, and are triple-junction III-V germanium solar cells, each with an active surface area of 8.751 mm². The cost of solar cells based on compounds of III-V element materials, named according to the groups of the periodic table that they belong to, has confined the devices to niche applications, such as drones and satellites. These are applications where low weight and high efficiency are more pressing concerns than costs.

The scientists mounted the 4-cell CPV SMT module on a 2-axis solar tracker from the Helios platform at the University of Sherbrooke.

The group took a series of electrical and temperature measurements on the system under real operating conditions and also conducted a series of simulations based on the finite element model (FEM), which is a numerical technique used to perform finite element analysis (FEA) of physical phenomenon.

Through their analysis and experiments, the academics found that the dimensions of the metal ribbon at the back of each cell and the metal coverage ratio of the PCB are key factors for the thermal management of the CPV module, while the other components have a negligible impact on the module temperature.

“The temperature of the solar cell can be kept below 80 C over a wide range of dimensions of the metal ribbon behind the solar cell, both for a metal coverage of the PCB of 0 % or 100 %,” they further explained. “However, this dimensional range is much wider when the metal coverage ratio is 100 % than when the metal coverage ratio on the PCB is 0 %.” The simulation also showed that the temperature of the solar cells may reach 54 C with a copper ribbon and 57 C with an aluminum ribbon.

The system was described in the paper “Finite element modeling and experimental validation of concentrator photovoltaic module based on surface Mount technology,” published in Solar Energy Materials and Solar Cells. “These results demonstrate that in addition to simplifying the assembly process, using SMT for CPV modules fabrication can enhance heat dissipation both by the metallic layer on the glass PCB and on the back side contact,” the researchers concluded. “This opens the door to simpler CPV modules, higher performance CPV modules and higher concentration ratios.”

From pv magazine global

Chinese solar module manufacturer Longi unveiled a new module series based on its proprietary hybrid passivated back contact (HPBC) cell technology.

“Longi’s first-generation BC products were primarily positioned for the rooftop market, but the second generation of BC is entirely different,” the company said in a statement. “The Hi-MO 9 panel is mainly positioned for the ground-mounted utility market.”

The new product is available in eight versions with power output ranging from 625 W to 660 W and power conversion efficiency spanning from 23.1% to 24.4%. The open-circuit voltage is between 53.30 V and 54.00 V and the short-circuit current is between 14.85 A and 15.41 A.

The double-glass modules have a temperature coefficient of -0.28%/C and a maximum system voltage of 1,500. Their size is 2,382 mm x 1,134 mm x 30 mm and their weight is 33.5 kg. They also feature IP68 junction boxes, an anodized aluminum alloy frame, and 2.0 mm coated tempered glass.

The new products come with a 12-year product warranty and a 30-year linear power output warranty, with the 30-year end power output being guaranteed to be no less than 88.85% of the nominal output power.

“In the second-generation BC product, the company has comprehensively optimized the bifaciality issue,” the company said, noting that the bifaciality factor cannot generally be very outstanding in back contact technologies. “However, taking this into full consideration, the overall life-cycle power generation capability we display now an improvement of 6% to 8%,” it added, without providing more details.

The company has not revealed yet all the technical aspects of its HPBC cell technology. It previously said it’s an extension of p-type interdigitated back-contact (IBC) technology that combines the structural advantages of PERC, TOPCon, and IBC solar. Additionally, BC technology can be combined with p-type wafers, for which Longi has substantial production capacities, giving it an advantage over the more common IBC technology.

In March, Longi launched its Hi-MO X6 Explorer and Hi-MO X6 Guardian modules, and last week it introduced the Hi-MO X6 Scientist panel.

From pv magazine Global

Bosch Home Comfort Group, a unit of German industrial conglomerate Robert Bosch GmbH, has launched new water source heat pumps intended for use in both new buildings and renovation projects.

“What we have solved for with our Bosch CL and RL Series heat pumps is a need for an HVAC unit design where high-quality and efficiency meet accessibility,” the company said in a statement. “Not only will these products make the jobs of techs and installers more seamless, but they will also offer them a deeper product portfolio to meet their customers’ needs and wants.”

The company said both products are available with both a vertical and a horizontal cabinet, use R-454B as a refrigerant, and rely on water coil and air coil freeze protection.

The CL Series has a size of ½ to 6 tons  The heat pump’s number of tons doesn’t refer to its weight but to the tons of heat a home needs. Its dimensions range from 48.3 cm x 48.3 cm x 58.4 cm to 61.0 cm x 83.8 cm x 147.3 cm. Its coefficient of performance spans from 4.45 to 4.90, depending on the size.

The CL Series also features a swinging electrical box, a slide-out blower on the vertical units, and designated compartments for high and low voltage components. “Together, these features not only improve safety conditions for technicians and installers, but also streamline routine services and repairs by offering greater accessibility to the unit’s compressor, air coils and other internal components,” the manufacturer said.

As for the RL Series, Bosch said its size and COP are the same as the CL Series. “Similar to the commercial model, the Bosch RL Series is equipped with a swinging and divided electrical box for faster and safer maintenance, as well as a slide-out blower on the vertical units,” the company added.

This series also features permanent split capacitor motors (PSC) and a unit protection module (UPM) that interfaces directly
with thermostats to provide time delays and protect the unit against freezing.

The two products come with a 1-year parts limited warranty and a 5-year compressor limited warranty.

From pv magazine Global

Chinese solar module producer JinkoSolar said it has achieved a 33.24% power conversion efficiency for a perovskite-silicon tandem solar cell based on n-type wafers.

The company said the results have been certified by the Shanghai Institute of Microsystem and Information Technology under the CAS. In its previous attempts, JinkoSolar achieved a cell efficiency of 32.33% for the same device configuration.

“This breakthrough in conversion efficiency for the perovskite/TOPCon tandem solar cell has been achieved through various materials and technology innovations including ultra-thin poly-Si passivated contact technology, novel light-trapping technology, intermediate recombination layer with high light transmittance and high carrier mobility, and efficient surface passivation technology using hybrid materials,” the manufacturer said, without providing any additional technical details.

Researchers from Germany’s Fraunhofer Institute for Solar Energy Systems (Fraunhofer ISE) recently said that the practical power conversion efficiency potential of perovskite-silicon tandem solar cells could reach up to 39.5%. Researchers said exceeding this efficiency threshold requires a change in cell architecture, replacing buckminsterfullerene (C60) with a more transparent electron transport layer, and finding more transparent alternatives to indium tin oxide (ITO) layers.

From pv magazine Global

TCL Zhonghuan has revealed a plan to become a majority shareholder of Singapore-based solar module manufacturer Maxeon. The Chinese company said it would finalize the deal through a number of financial transactions, including the issuance of convertible bonds and additional shares via private placement.

TCL Zhonghuan said it aims to use up to $197.5 million for the acquisition, which will increase its shareholding in Maxeon from 22.39% to a controlling stake of at least 50.1%. If the transaction is completed, Maxeon will become a subsidiary controlled by TCL Zhonghuan, and its results will be consolidated into the Chinese company’s financial statements.

“The series of major investments we announced yesterday in conjunction with our strategic partner, TZE, will fortify our balance sheet, and this recapitalization places Maxeon in a solid financial position and reinforces our role as a leading participant in the renewable energy market,” a Maxeon spokesperson told pv magazine. “Specifically, TZE has committed to a $97.5 million convertible bond issuance followed by a $100 million equity investment, both subject to regulatory approvals.  These investments are occurring during a period of significant solar industry volatility and will enhance Maxeon’s ability to navigate the resultant market challenges with confidence while positioning the company to continue its long history of product innovation and drive growth and increased profit.”

In October 2023, Maxeon announced a plan to lay off 15% of its employees to manage the impacts of lower shipments from a distributed-generation client in North America and an “industry-wide demand slowdown” in global distributed-generation markets. Maxeon CEO Bill Mulligan said in a statement at the time that the company had decided to “streamline” operations, invest in new technologies, and develop a mix between the distributed-generation and utility-scale markets due to “rapidly changing market and industry conditions.”

From pv magazine Global

Sharp has developed new n-type monocrystalline bifacial solar panels based on tunnel oxide passivated contact (TOPCon) cell technology.

The NU-JC440 and NU-JC430 modules both feature glass-backsheet architecture, 108 half-cut solar cells based on M10 wafers, and a 16-busbar design.

“The NU-JC440 TOPCcon n-type monocrystalline panel features a sleek black frame and white backsheet,” the manufacturer said in a statement. “The NU-JC430B module is an all-black n-type monocrystalline module featuring a black backsheet and black frame.”

The NU-JC440 panel has a power conversion efficiency of 22.53% and a power output of 440 W. The NU-JC430 module has an efficiency rating of 22.02% and an output of 430 W.

The IEC61215- and IEC61730-certified panels measure 1,722 mm x 1,134 mm x 30 mm and weigh 20.7 kg. They can be used in PV systems with a maximum voltage of 1,000 V and an operating temperature between -40 C and 85 C. They also feature an operating temperature coefficient is -0.30% per C.

The company offers a 30-year linear power output guarantee and a 25-year product guarantee. The 30-year end power output is guaranteed to be no less than 87.5% of the nominal output power.

From pv magazine Global

Thermophotovoltaics (TPV) is a power generation technology that uses thermal radiation to generate electricity in photovoltaic cells. A TPV system generally consists of a thermal emitter that can reach high temperatures, near or beyond 1,000 C, and a photovoltaic diode cell that can absorb photons coming from the heat source.

The technology has drawn the interest of scientists for decades, because it can capture sunlight in the entire solar spectrum and has the technical potential to beat the Shockley-Queisser limit of traditional photovoltaics. However, the efficiencies reported thus far have been too low to make it commercially viable, as TPV devices still suffer from optical and thermal losses.

With this in mind, a group of researchers at the University of Michigan in the United States have developed TPV cells that reportedly address these issues and achieve a power conversion efficiency of 44%.

“This level of efficiency could enable thermal battery systems to reach a price point needed to put most of the grid on wind and solar power,” said research’s lead author, Andrej Lenert, told pv magazine. “Such systems have to continuously draw energy from a hot storage material such as graphite as it cools from its maximum allowable temperature. Getting 40% efficiency at storage temperatures as low as 1300 C, versus requiring 2000 C as previously, means these batteries could possibly get twice as much energy per kg of graphite.”

According to Lenert, this result represents a major improvement in TPVs and solid-state heat-to-power generation at large. “It is a culmination of several years of intense research to understand how to minimize energy losses and mechanical issues in air-bridge TPV cells, which we originally reported in 2020,” he added. “Those cells were 32% efficient and relatively fragile, now we are closer to 44% and have a much more robust technology. Though still not at the kW or MW scale, this result demonstrates what is possible with single-junction TPV cells, fulfilling decades-old theoretical predictions made by the TPV community.”

In the study “High-efficiency air-bridge thermophotovoltaic cells,” which was recently published in Joule, Lenert and his colleagues described the cell as an air-bridge indium gallium arsenide (InGaAs) device that can absorb most of the in-band radiation to generate electricity. It can also serve as a nearly perfect mirror, with almost 99% reflectance.

The cell was built with a silicon substrate, an air bridge structure with a thickness of 570 nm, a rear contact made of gold (Au), titanium (Ti), an n-doped InGaAs layer, a membrane layer with a thickness of 1 µm, an InGaAs absorber, and a front contact made of Au, Ti, platinum (Pt), and p-doped InGaAs. Three different absorber layers were tested with energy bandgaps of 0.74 eV, 0.90 eV, and 1.1 eV, respectively. 

The air-bridge layer is embedded between the three active layers and the rear Au mirror to enhance backside reflectance and recovery of out-of-band photons. The membrane support layer is intended to minimize buckling of the free-standing semiconductor membrane and ensure a single cavity mode within the air layer.

“The combination of a nanoscale air layer and a relatively high coverage of conductive rear electrodes ensures that the air-bridge thermal resistance is small compared with that of the Si substrate,” the scientists emphasized. “Additionally, the design includes a membrane support layer to minimize buckling of the free-standing semiconductor membrane and ensure a single cavity mode within the air layer.”

The researchers found that the cell with an absorber bandgap of 0.90 eV achieved the best performance. It reached a power conversion efficiency of 43.8% at 1,435 C. “It surpasses the 37% achieved by previous designs within this range of temperatures,” Lenert stated. “We’re not yet at the efficiency limit of this technology. I am confident that we will get higher than 44% and be pushing 50% in the not-too-distant future,” added research co-author, Stephen R. Forrest.”

These results, according to the research group, also promise significant improvements in the device’s round-trip efficiency. “It’s a form of battery, but one that’s very passive. You don’t have to mine lithium as you do with electrochemical cells, which means you don’t have to compete with the electric vehicle market,” Forrest further explained. “Unlike pumped water for hydroelectric energy storage, you can put it anywhere and don’t need a water source nearby.”

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 research group at the University of Toledo in the United States has designed a four-terminal (4T) tandem solar cell with a top device relying on a perovskite absorber with a tunable wide-bandgap and a bottom cell using a commercially established narrow-bandgap absorber technology made of cadmium telluride (CdTe).

“While a lot of work has been done on perovskite-silicon, perovskite-CIGS, and perovskite-perovskite tandem cells, perovskite-cadmium telluride tandem solar cells are relatively unexplored,” the scientists said. “Although the efficiency potential of CdTe-based tandems is likely lower than CIGS-based tandems due to the higher bandgap of the CdTe bottom cell, the broader commercial success of CdTe solar cells makes them a point of interest in investigating thin-film tandem applications.”

The academics said a key element of the solar cell is the transparent back contact (TBC) technology used for the top tunable wide-bandgap perovskite cell. For the construction of these contacts, they used indium zinc oxide (IZO) as an alternative to well-established indium tin oxide (ITO).

They prepared the IZO films through the radio frequency (RF) magnetron sputtering technique, which is an approach involving alternating the electrical potential of the current in a vacuum environment at RFs.

They also explained that their efforts were aimed at identifying the ideal IZO thickness, as this plays a crucial role in improving the performance and optical transmittance of the semitransparent perovskite top cell by increasing the perovskite bandgap allowing more long-wavelength photons to transmit and enter the CdSeTe bottom cell. In turn, this compensates for a typical optical loss factor in a 4T tandem configuration.

The top cell was constructed with a substrate made of glass and indium tin oxide (ITO), a hole transport layer (HTL) made of nickel(II) oxide (NiOx), a layer made of a phosphonic acid called methyl-substituted carbazole (Me-4PACz), the perovskite absorber, an electron transport layer (ETL) relying on buckminsterfullerene (C60), a tin oxide (SnOx) buffer layer, and the IZO back contact.

The bottom cell was designed to have a substrate made of glass and ITO, an ETL made of tin oxide (SnO2), a cadmium telluride (CdTe) absorber, a cadmium selenium telluride (CdSeTe) layer, a copper thiocyanate (CuSCN) HTL, and a gold metal contact.

Both cells were covered with an anti-reflecting coating.

The best tandem cell configuration was achieved when the absorber of the top cell was tuned to have an energy bandgap of 1.76 eV. With this value, the device reached an overall power conversion efficiency of 25.1%.

The top cell was found to achieve an efficiency of 17.93%, an open-circuit voltage of 1.315 V, a short-circuit current of density of 17.11 mA cm², and a fill factor of 79.7%. The bottom cell showed an efficiency of 7.13%, an open-circuit voltage of 0.842 V, a short-circuit current of density of 11.15 mA cm², and a fill factor of 76.0%.

“The result proves the concept that 4T perovskite–CdSeTe tandem configuration can be used to improve the efficiency of commercial CdSeTe thin-film solar cells,” the researchers stated, adding they are currently outlining a roadmap to increase the device’s efficiency to 30%. “Our analysis reveals that high-efficiency 4T perovskite–CdSeTe tandem solar cells are feasible with the future advance of both PV cells.”

The details of the new cell design can be found in the study “Four-Terminal Perovskite–CdSeTe Tandem Solar Cells: From 25% toward 30% Power Conversion Efficiency and Beyond,” which was recently published in RRL Solar.

The University of Toledo developed several types of CdTe solar cells over the past years. The devices include, among others, a 20%-efficient cell based on a commercial tin(IV) oxide (SnO₂) buffer layer, a 17.4%-efficient device using a layer of copper-aluminum oxide to the rear side of the CdTe thin film, and a solar cell based on an indium gallium oxide (IGO) emitter layer and a cadmium stannate (CTO) transparent conductor as the front electrode.

From pv magazine Global

Quilt has launched its first product – a wall-mountable (or tabletop) heat pump for cooling and heating in residential applications.

“The Quilt system is anchored by our outdoor unit, which is sized to power up to two indoor units,” the US-based startup said in a statement. “This 2:1 ratio means our outdoor units are quieter, more compact, and more efficient than larger units, saving you more energy and money than higher ratio systems.”

The system measures 711 mm x 965 mm x 406 mm and uses R32 as a refrigerant. Its cooling capacity at 46.4 F (8 C) ranges from 2,500 BTU/hour to 20,500 BTU/hour, while its cooling capacity at 95 F (35 C) spans from 2,500 BTU/hour to 20,500 BTU/hour.

The heat pump features a COP of 4 for heating at 46.4 F and 2 at 5 F (-15 C). The COP for cooling is 4 at 95 F.

The new product has an input power of 208/230V and noise levels of 27 dBA to 47 dBA, which the manufacturer describes as “quieter than rainfall.” It is available in a real white oak veneer or a white option that is paintable or ready for wallpaper.

“Quilt is a full generation ahead of the best systems in the market today and priced competitively at $6,499 per room before point-of-sale rebates,” the manufacturer said. “This includes everything from the intuitive indoor unit, Dial for room-by-room control, design-forward outdoor unit, modern app, professional installation by Quilt, permitting support from a Quilt Advisor, and ongoing support.”

In mid-April, Quilt raised $33 million through a funding round co-led by Energy Impact Partners and Galvanize Climate Solutions, with participation from Lowercarbon Capital, Gradient Ventures, MCJ Collective, Garage Capital, Incite Ventures, and Drew Scott.

“Quilt will first launch in the Bay Area, followed by Los Angeles, and then expand to new markets in the U.S. to meet rising demand for a smart, intuitive, design-forward heat pump option,” the company said at the time.

China-based heating specialist Midea has developed a new outdoor, central ducted heat pump for residential applications.

“This latest generation of the Evox series, featuring the Evox G³ Heat Pump and Evox G³ Air Handling Unit (AHU), represents the future of electric, inverter-driven heat pump technology as the solution for home heating and cooling upgrades, designed to deliver unparalleled heating/cooling comfort, performance and ease of installation across North America,” the manufacturer said in statement.

It claimed that the new product is suitable for all climates and is designed “to defy harsh winter temperatures.”

The Evox G³ Heat Pump has a size of 1.5 tons to 5 tons and a coefficient of performance of 1.8. It is 36 cm to 53 cm wide, which the company said ensures easy deployment in challenging spaces such as attics and basements. It can reportedly provide up to 100% heating output down to -13 F (-25 C) and operate “effectively” down to -22 F (-30 C).

The heat pump also features an enhanced vapor injection (EVI) technology and a multi-layer heat exchanger. These components enable it to operate with auxiliary sources of heat and achieve high comfort levels also in extremely cold weather conditions.

“Evox G³ also has you covered in the summer, with a cooling efficiency of up to 19 SEER2 that can provide energy savings of up to 32.5% compared to the conventional 14.3 SEER systems currently popular on the market,” said the company.

The EVI technology combines a two-stage refrigerant compression process with an intermediary injection of additional refrigerant vapor, which reportedly increases overall performance and coefficient of performance.

“The injection of vapor refrigerant facilitates higher output temperatures while simultaneously expanding the operational range of the heat pump, thereby ensuring outstanding functionality even in sub-zero conditions,” said Midea. “Its multi-position installation configuration means contractors can stock one stock keeping unit and install it in six configurations.”

From pv magazine Global

The U.S. government decided to raise the tariff rates it applies to solar cells imported from China from 25% to 50%.

“The tariff increase will protect against China’s policy-driven overcapacity that depresses prices and inhibits the development of solar capacity outside of China,” the White House said in a statement. “China has used unfair practices to dominate upwards of 80 to 90% of certain parts of the global solar supply chain, and is trying to maintain that status quo. Chinese policies and non-market practices are flooding global markets with artificially cheap solar modules and panels, undermining investment in solar manufacturing outside of China.”

The Biden administration has also decided to raise tariff rates on aluminum and steel imported from China, from 0% to 7.5% up to 25%, as well as those applied to semiconductors, from 25% to 50%.

In addition, it has decided to raise tariffs imposed on electric vehicles from 25% to 100% and those on lithium-ion EV batteries from 7.5%% to 25%. The government has also increased the tariffs on ship-to-shore cranes and medical products.

“American workers and businesses can outcompete anyone—as long as they have fair competition. But for too long, China’s government has used unfair, non-market practices,” the US government said. “China’s forced technology transfers and intellectual property theft have contributed to its control of 70%, 80%, and even 90% of global production for the critical inputs necessary for our technologies, infrastructure, energy, and health care – creating unacceptable risks to America’s supply chains and economic security.”

From pv magazine Global

Chinese solar module manufacturer Longi has achieved a power conversion efficiency of 27.30% for an HBC solar cell. Germany’s Institute for Solar Energy Research (ISFH) has confirmed the result.

The new efficiency record beats the previous world record of 27.09%, which was also set by Longi at the end of last year.

At the time, Longi said the result was enabled through a new laser graphical process that costs less than conventional high-cost photolithography processes.

“This substitution has effectively reduced the cost of the BC cell,” the company said in a statement, noting that the HBC architecture also minimizes the reliance on traditional indium-based transparent conductive oxide (ITO). “This breakthrough has propelled the commercialization of HBC solar cells, featuring independent intellectual property and cost-effectiveness.”

In early November, Longi announced a power conversion efficiency of 33.9% for a perovskite-silicon tandem solar cell.

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.

From pv magazine Global

The global solar cell and module manufacturing industry is currently operating at a utilization rate of approximately 50%, according to the IEA’s Advancing Clean Technology Manufacturing report. It said that global investments in new solar factories amounted to $80 billion in 2023 alone, which is two times more than in 2022.

The Chinese solar industry accounted for approximately 95% of global investments in wafer production capacity last year, 96% of investment in polysilicon production facilities, and 83% of module factories. The IEA said that around 440 GW of 500 GW of total cell and module capacity was deployed throughout the world last year.

“Existing manufacturing capacity for solar PV modules and cells could today achieve what is necessary to meet demand under the NZE Scenario in 2030 – six years ahead of schedule, with only modest gaps remaining for the upstream steps of wafer and polysilicon manufacturing,” the report noted. “While the sharp increase in supply has driven down module prices, supporting wider consumer uptake, stockpiles of solar PV modules are growing and there are signs of downscaling and postponements of planned capacity expansions, particularly in China.”

The agency said that around 80% of the world’s PV manufacturing industry is currently concentrated in China, with India and the United States accounting for 5% each and Europe at just 1%.

“The high geographical concentration of the full solar PV supply chain is unlikely to change significantly on the basis of announced projects, with China’s share of capacity for modules, cells and wafers decreasing marginally and increasing for polysilicon, to reach close to 95% in 2030,” said the IEA.

It also presented data on levelized cost of manufacturing, upfront and operational costs, as well as national incentives for manufacturing. It said that a 56 GW solar module factory under construction by JinkoSolar in China’s Shanxi Comprehensive Reform Demonstration Zone is cheaper than national average values.

“While estimates are not outturn costs, the facility is projected to come in at $7.8 billion, or $140/kW for full-chain solar PV manufacturing, compared with our national average figure of $185/kW for China,” said the IEA.

The report also includes data on global wind energy, electrolyzer production, and heat pump manufacturing.

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.

From pv magazine Global

NREL has updated its Best Research-Cell Efficiency 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 US Department of Energy’s research institute told pv magazine, noting the chart also includes important results achieved in the first quarter of this year. “The format of the chart will soon change to include hybrid tandems.”

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 US-based thin-film module maker First Solar for a solar cell based on copper, indium, gallium and diselenide (CIGS) technology.

With the interactive version of the chart, users can pull up decades of research data and compare custom charts that focus on specific technologies or time periods. They can find data on a cell’s current, voltage output, and fill factor, in addition to efficiency. The availability of those details will depend on the information in NREL’s records.

The highest research cell efficiency recorded in the chart is 47.6%, for a four-junction cell developed by Germany’s Fraunhofer Institute for Solar Energy Systems (Fraunhofer ISE).

From pv magazine Global

Maxeon, a Singapore-based solar module manufacturer, has filed two separate patent infringement lawsuits against South Korea-based competitor Hanwha Qcells and Norway-headquartered REC Solar Holdings AS in the US District Court for the Eastern District of Texas. The alleged patent violations are related to an unspecified TOPCon solar cell technology.

“The company has a global patent portfolio of over 1,650 granted patents and more than 330 pending patent applications protecting the innovations underpinning its IBC, Shingled Hypercell, and TOPCon technologies,” Maxeon said, without providing further details.

In late March, Maxeon filed a similar lawsuit against Canadian Solar. Maxeon had previously sued Canadian Solar in Japan for patent infringement in 2020. In that lawsuit, Maxeon alleged that Canadian Solar Japan infringed upon its Japan Patent No. JP6642841B2, which is related to its shingled solar modules. The two companies reached a settlement agreement in April 2022.

In November 2023, Maxeon sued Chinese competitor Aiko Solar Energy, as well as wholesaler Memedo GmbH, for alleged patent infringement regarding a specific design related to the architecture of back contact solar cells.

And in June 2023, Maxeon had filed a lawsuit against Tongwei Solar in Germany for the alleged infringement of its European patent for shingled solar cell technology.

From pv magazine global

Johnson Controls has introduced a new heat pump series for residential applications.

“The York YH5 15.2 SEER2 2-Stage Heat Pumps are engineered for year-round comfort and energy efficiency,” a spokesperson from the company told pv magazine. “These heat pumps are specifically designed to be matched with a York residential gas furnace to create a hybrid comfort system that automatically switches between heat sources based on energy costs or capacity.”

The new heat pumps use R-454B as the refrigerant and have a size ranging from 1.5 tons to 5 tons. The heat pump’s number of tons doesn’t refer to its weight but to the tons of heat a home needs.

The systems have reportedly a seasonal energy efficiency ratio (SEER2) of up to 16 and a heating seasonal performance factor (HSPF2) of up to 8.1. Their coefficient of performance (COP) ranges between 3.24 and 3.40, according to the manufacturer.

They also feature a cooling capacity spanning from 22.2 MBtuh to 58.5 MBtuh. Sound levels are reportedly as low as 67  dBA.

“Designed to simplify serviceability, the YH5 heat pump features top or side compressor access, a swing-out control box, field-installed TXVs, removable fan guard and individually removable coil guards for fast and easy servicing,” the spokesperson said. “Additionally, equipment information, troubleshooting support and helpful tools – including an intelligent refrigeration detection system (RDS) – can be conveniently accessed via the DS Solutions App simply by scanning a QR code located on the heat pump.”

The new heat pump series is compatible with York humidifiers, dehumidifiers, air filters, ultraviolet air purifiers and energy recovery ventilators, as well as with most heat pump thermostats.

From pv magazine Global

A group of researchers in Germany has developed a comprehensive optoelectrical simulation model for triple-junction solar cells based on subcells relying on perovskite, perovskite, and crystalline silicon, respectively.

The model is intended to define an efficiency roadmap for improving the optical properties of these solar cells within realistic boundary conditions. “The roadmap includes the adaption of the perovskite absorber thicknesses, modifying bandgaps, employing a fully textured cell, and optimizing the thicknesses of the interlayers between the absorbers,” the scientists explained. “We calculate the respective photocurrent of each step and compare it against the theoretical limit.”

For their modeling, the academics chose the Sentaurus TCAD, which is a multidimensional simulator capable of simulating the electrical, thermal, and optical characteristics of silicon-based devices. It is also used to simulate the optoelectronic characteristics of semiconductor devices, such as image sensors and PV cells.

“This tool has already demonstrated its capability in accurately describing the optical properties of perovskite tandem solar cells,” they said, referring to previous, similar research they conducted on perovskite-silicon tandem cells. In this work, they concluded that the practical power conversion efficiency potential of perovskite-silicon tandem devices may reach up to 39.5%.

In their most recent work, the researchers initially assumed the triple junction cell to be based on a bottom silicon heterojunction cell with an indium tin oxide (ITO) layer and a silver (Ag) metal contact, a middle perovskite cell with an energy bandgap of 1.57 eV, and a top perovskite cell with a bandgap of 1.84 eV.

In the optimization process, their efforts were directed to increase the photocurrent of all three cells. They initially varied the thicknesses of the three absorbers and then they adjusted the perovskites bandgaps. Moreover, they applied a textured front side to mitigate reflection losses and used thinner interlayers. “Adapting the perovskite absorber thicknesses is rather simple but has the potential to achieve current matching between the top and middle cell,” the group emphasized. “This way the current can be improved significantly.”

The scientists also gauged the thickness of the anti-reflective coating based on magnesium fluoride (MgF2) by reducing its thickness from 130 nm to 90 nm. They also initially increased the thickness of the middle cell’s perovskite absorber, which they said reduces photon absorption in the silicon subcell, but offers improved absorption in the top and middle devices, thus increasing photocurrent at the triple-junction cell level.

The simulation showed that the best cell configuration may potentially achieve a power conversion efficiency of 44.3%, an open-circuit voltage of 3480 mV, a short-circuit density of 14.1 mA cm⁻², and a fill factor of 90.1%. This was achieved with a middle perovskite cell with an energy bandgap of 1.46 eV and a top perovskite cell with a bandgap of 1.97 eV.

“On the other hand, we showed that the range of the top-cell bandgap could be chosen between 1.8 and 2.0 eV, depending on the top cell thickness varying between 200 and 800 nm, respectively, for which each a bandgap/thickness tuple exists to achieve global current matching,” the scientists stressed. “Nevertheless, we raised awareness for choosing thicker perovskite layers with higher bandgap to unleash the full open-circuit voltage potential of the top cell.”

Their findings are available in the paper “Optoelectrical Modeling of Perovskite/Perovskite/Silicon Triple-Junction Solar Cells: Toward the Practical Efficiency Potential,” which was recently published in RRL Solar. The research team was formed by scientists from the University of Freiburg and Fraunhofer Institute for Solar Energy Systems (Fraunhofer ISE).

From pv magazine Global

Thornova Solar, the US unit of Chinese PV manufacturer Sunova Solar, has launched a new bifacial TOPCon PV module for applications in large scale solar projects.

The TS-BWT66-G12 dual-glass module has a size of 2,384 mm x 1,303 mm x 35 mm and weighs 38.5 kg. It features a power conversion efficiency spanning from 22.4% to 23.2% and a temperature coefficient of -0.29% per C.

Its power output ranges from 695 W to 720. The open-circuit voltage is between 47.23 V and 47.98 V and the short-circuit current is of 18.68 A to 18.79 A. It can operate with a system voltage of 1,500 V and temperatures ranging from -40 C to 85 C.

The new product also features a transparent white mesh backsheet, 2.0 mm heat-strengthened glass, and an anti-reflective coating. It comes with a 15-year product warranty and a 30-year performance warranty.

“Annual linear degradation over 30 years is 0.4%, with a maximum degradation in the first year of 1.0%,” the manufacturer said in a statement.

Thornova Solar is planning to build a solar cell and module factory at an unspecified location in the United States in 2025.

“We plan to produce both cells and modules in the United States in 2025, enabling buyers to take full advantage of US tax credits for solar modules with domestic content,” Thornova CEO, William Sheng, said. “With the rapid growth in solar power generation in the U.S., we aim to provide a strong, reliable U.S.-based supply of modules that are optimally designed for utility-scale projects.”

Sunova Solar currently operates three manufacturing factories in China and Vietnam. The company said that as of December 2023, it had shipped more than 4 GW of cumulative modules throughout the world.

From pv magazine Global

Singapore-based solar module manufacturer Maxeon has filed a patent infringement lawsuit against Chinese-Canadian competitor Canadian Solar in the US District Court for the Eastern District of Texas.

The alleged patent infringement is related to an unspecified TOPCon solar cell technology.

“Maxeon has a strong heritage in developing solar cell technology, leading the development and commercialization of tunnel oxide passivated contacts,” said Marc Robinson, associate general counsel for Maxeon. “Years before the moniker ‘TOPCon’ started to be used in the industry to describe a tunnel oxide passivated contact-based solar cell, our scientists and engineers had developed several ways to implement TOPCon technology into both back contact and front contact solar cells. Maxeon has many patents related to TOPCon technology, with inventions drawn to fundamental TOPCon solar cell architectures dating back to the 2000s. This is Maxeon’s first action to enforce its valuable patent rights in the United States, and Maxeon will continue to vigorously enforce its patent rights in the United States and its other markets.”

Maxeon previously sued Canadian Solar in Japan for patent infringement in 2020. In the lawsuit, Maxeon alleged that Canadian Solar Japan infringed upon its Japan Patent No. JP6642841B2, which is related to its shingled solar modules. The two companies reached a settlement agreement in April 2022.

Canadian Solar has faced similar patent claims in the United States. PV manufacturer Solaria filed three different patent infringement claims against the company, also related to the process of separating photovoltaic strips from solar cells for use in shingled modules.

In November 2023, Maxeon sued Chinese competitor Aiko Solar Energy, as well as wholesaler Memedo GmbH, for alleged patent infringement regarding a specific design related to the architecture of back contact solar cells.

And in June 2023, Maxeon had filed a lawsuit against Tongwei Solar in Germany for the alleged infringement of its European patent for shingled solar cell technology.

Singapore’s Maxeon has announced that it has achieved an aperture module conversion efficiency of 24.9% for a full-scale Maxeon 7 PV panel.

The US Department of Energy’s National Renewable Energy Laboratory (NREL) confirmed the result. The Maxeon 7 module is based on interdigitated back contact (IBC) technology.

For the same panel, Maxeon achieved a power conversion efficiency of 24.7% in June.

“Maxeon 7 cells feature a unique and patented design to mitigate hotspot risk from cell cracking and heat buildup under shaded conditions.” the manufacturer said in a statement. “This results in increased reliability and power output, as supported by the Company’s 40-year warranty.”

The manufacturer hosts a Maxeon 7 pilot assembly line in the Philippines.

From pv magazine Global

U.S.-based residential and commercial heating products manufacturer U.S. Boiler has launched a monobloc air-to-water heat pump for applications in residential buildings.

The manufacturer stated the new hydronic system is suitable for either new buildings or retrofits and said it can also be used as a stand-alone heat source or in dual-fuel applications. It has a 5-ton capacity rated at 60 thousand British thermal units (BTUs) per hour (MBH)

The Air-to-Water Hydronic Heat Pump reportedly features a coefficient of performance of up to 3.95 and is able to achieve supply temperatures of up to 60 C. It uses difluoromethane (R32) as the refrigerant, which has a global warming potential (GWP) of 675.

The system consists of a monobloc heat pump, a touchscreen controller, a buffer tank, a circulator, a flat plate heat exchanger, a pressure relief valve, a drain valve, relays, and a dual fuel controller.

The new product also relies on DC inverter enhanced vapor injection (EVI) technology that purportedly enables homeowners to have “reliable” heating at low temperatures down to -10 C. EVI is a technology used on our cold climate heat pumps to achieve higher performance at lower temperatures and to reduce the discharge temperature.

The manufacturer also describes the heat pump as “extremely quiet,” with operating sound levels as low as 39 decibels.

“The new system is available as a stand-alone unit, or as part of two different packages, depending on whether the heat pump will be the only source of hydronic heat in the home or in tandem with a boiler,” it also said.

From pv magazine Global

An international research team has investigated the effect of inverter clipping on mitigating soiling losses in PV systems and has found that this strategy may not be as effective as commonly thought.

Inverter clipping occurs when a PV system’s DC energy is larger than the maximum input size of the inverter. This saturates the inverter and the excess DC energy is not converted into AC.

“Because of this masking effect, inverter undersizing has often been suggested as a practical soiling mitigation strategy,” the research group stated. “Indeed, the soiling losses are not visible from the AC side during clipping if they are not bigger than the difference between the energy rating of the modules and the capacity of the inverter.”

In the paper “Quantifying the impact of inverter clipping on photovoltaic performance and soiling losses,” published in Renewable Energy, the scientists explained that their theoretical work aimed at answering the typical question that PV modelers and soiling experts are often asked: “Isn’t inverter clipping enough to mitigate the effects of soiling on photovoltaic systems?”

From pv magazine Global

China’s JinkoSolar was the world’s largest PV module supplier in 2023, with 78.5 GW of global shipments.

In its financial results for 2023, the company said that its panel shipments increased by 76.4% year on year.

“At the end of the fourth quarter, we became the first module manufacturer in the world to have delivered a total of 210 GW solar modules, covering over 190 countries and regions,” it said, in reference to its cumulative shipments.

JinkoSolar recorded a turnover of CNY 118.68 billion ($16.72 billion), up 42.8% from 2022. It also posted a net profit of CNY 3.45 billion.

“Benefiting from our efforts in cost optimization, our profitability for the full year significantly improved year-over-year, with gross margin at 16.0%, compared to 14.8% in 2022,” said Jinko CEO Xiande Li. “Module shipment in the fourth quarter was 26.3 GW, exceeding our guidance.”

Li said that around half of the modules shipped in the fourth quarter went to the Chinese market, where they were sold at lower prices.

In its outlook for 2024, JinkoSolar said it hopes to ship between 100 GW and 110 GW.

“We expect our annual production capacity for mono wafers, solar cells and solar modules to reach 120 GW, 110 GW and 130 GW, respectively, by the end of 2024, with N-type capacity accounting for over 90% of total capacity,” it stated. “By then, we believe mass-produced N-type cell efficiency will have reached 26.5%.”

IRENA has released a new report describing the future actions that should be taken to reach the renewable energy targets set by the COP28 conference held in Dubai in December.

“We need to deploy around 1.1 TW of renewable energy capacity per year by 2030. Every technology that provides a reduction in CO2 emissions is good, but technology neutrality may not be the solution, as only renewables ensure the necessary speed and scale to achieve the proposed targets,” said IRENA President Francesco La Camera, in reference to the slow pace at which nuclear energy is currently driving the global energy transition.

According to the official documents, 123 national governments and supranational blocs, including the European Union, have signed up to triple the world’s installed renewable energy generation capacity to at least 11 TW by 2030. The signatories also vowed to double the global average annual rate of energy efficiency improvements, from 2% to 4%, until the end of 2030.

La Camera noted the importance of creating a workforce for the energy transition. He also discussed the need to create incentives to foster the emergence of a green hydrogen market and to develop grid infrastructure and interconnection sea cables for global energy trade.

In the Tracking COP28 Outcomes report, IRENA said that annual investments in renewable power generation must surge from $570 billion in 2023 to $1,550 billion on average between 2024 and 2030. The report also said that the proposed COP28  target will not be reached without urgent policy intervention.

“G20 nations, for example, must grow their renewable capacity from under 3 TW in 2022 to 9.4 TW by 2030, accounting for over 80% of the global total,” said IRENA.

The organization also said that wider international cooperation, as well as the strategic use of public finances, will be key to achieving the COP28 goals.

“This requires structural reforms, including within multilateral finance mechanisms, to effectively support the energy transition in developing countries,” it stated.

From pv magazine Global

Researchers led by Dartmouth College in the United States have identified zintl-phosphide (BaCd2P2) as a potential new absorber material for thin-film solar cells after conducting a high-throughput (HT) computational screening among 40,000 promising inorganic materials.

“Based on its dopability, this material could be used as a p-type absorber layer for pn junction cells or as an intrinsic absorber layer for p-i-n cells,” the research’s corresponding author, Zhenkun Yuan, told pv magazine.

The group selected the inorganic materials from the Materials Project database, which is an open-access database describing material properties that can be used to accelerate the development of a given technology by predicting how new materials, both real and hypothetical, can be potentially utilized.

Through the screening, the scientists initially identified materials that offer a suitable band gap, small effective masses, and promising defect properties. “Among these promising candidates, we select the zintl-phosphide (BaCd₂P₂) and explicitly show that the computed nonradiative recombination rates in BaCd₂P₂ are better than or comparable with those in high-efficiency solar absorbers such as the halide perovskites,” they explained.

After identifying the material, the group found that zintl-phosphide can be very stable both in air and water. “You can put it out for six months and it will stay the same,” added co-author Geoffroy Hautier. “When you don’t have to worry about moisture and air contamination, that significantly reduces your costs.”

By conducting bright photoluminescence (PL) and time-resolved microwave conductivity (TRMC), it also found the material has a potential energy bandgap of 1.45 eV and a carrier lifetime of up to 30 ns.

“All of these results indicate that BaCd₂P₂ is a promising high-performance solar cell absorber with the potential to open a new avenue in PV for an entire family of Zintl AM₂X₂ solar absorbers, where A and M are +2 ions and X is a pnictogen,” the researchers said.

“We won’t have it as a solar panel tomorrow,” added Hautier, “but we think this family of materials is exceptional and worth looking at.”

Their findings were presented in the paper “Discovery of the Zintl-phosphide BaCd₂P₂ as a long carrier lifetime and stable solar absorber,” published in Joule.

From pv magazine Global

Researchers at Penn State University in the United States have fabricated a prototype of a hybrid energy system integrating solar cells for power production and radiative cooling for external cooling purposes.

Radiative cooling occurs when the surface of an object absorbs less radiation from the atmosphere and emits more. As a result, the surface loses heat and a cooling effect can be achieved without the need for power.

“The photovoltaic electricity generated in the dual system can be used for energy storage or be converted to alternating current by using an inverter,” the scientists said. “The coldness achieved on the transparent radiative cooler can be used to cool air or liquid, which can be driven by fan or pump, respectively, to interface with thermal systems for energy savings.”

The proposed system achieves simultaneous subambient daytime radiative cooling and photovoltaic electricity generation from the same area. “At night and during the day, the radiative cooler works as a 24/7 natural air conditioner,” said the research’s lead author Pramit Ghosh. “Even on a hot day, the radiative cooler is cold to the touch.”

The system consists of a transparent low-iron glass radiative cooler that is able to transmit 91% of sunlight, a visibly transparent infrared-opaque layer, and a 125 mm × 125 mm interdigitated back-contact (IBC) photovoltaic cell provided by US-based manufacturer Maxeon. The radiative cooler has no direct radiative heat exchange with the PV device.

The scientists tested the system in an outdoor environment at Penn State Sustainability Institute’s Sustainability Experience Center and found it could surpass the electricity saving of a bare solar cell by as much as 30%. “We demonstrated simultaneous subambient daytime radiative cooling at 5.1 C temperature reduction under solar irradiance of about 1,000 W/m² and solar power generation up to 159.9 W/m² from the same area,” they explained. “We experimentally achieved ambient cooling power of 63.8 W/m² under peak sunlight and ambient cooling power of 87.0 W/m² at night.”

The research group also assumed the power generated by the solar cell to be utilized to power a cooling system with a coefficient of performance (COP) 2.8, and found the cooling power of the hybrid system would be five times more than the daytime cooling power achieved in conventional solar-reflective radiative coolers.

“Our work highlights the significant opportunity of simultaneously harvesting both the sun and the cold universe for renewable energy at a level that can exceed the performance of using either resource alone,” it concluded.

The system was described in the study “Simultaneous subambient daytime radiative cooling and photovoltaic power generation from the same area,” which was recently published in Cell Reports Physical Science.

Radiative cooling was recently applied to solar panel cooling by researchers from Saudi Arabia’s King Abdullah University of Science and Technology (KAUST), Shanghai Jiao Tong University in China, Purdue University in the United States, the Catalan Institute of Nanoscience and Nanotechnology and the Instituto de Ciencia de Materiales in Spain, and the Jordan University of Science and Technology and the Australian College of Kuwait, among others.

From pv magazine global

Researchers at the University of Rajshahi in Bangladesh have simulated a dual-junction tandem solar cell based on two PV devices reyling on absorbers made of cadmium telluride (CdTe) and iron disilicide (FeSi2).

Inorganic FeSi2-based solar cells have recently drawn a lot of attention from the scientific community as these devices offer superior thermal stability and good optoelectronic properties compared to conventional solar cells. Furthermore, Fe and Si used to form FeSi₂ are abundant in nature.

The scientists explained that their tandem cell takes advantage of combining the larger bandgap of the top CdTe cell and the smaller bandgap of the bottom FeSi2 cell. “The top cell transforms photons with elevated energy efficiently while minimizing thermalization losses and transmitting the solar spectrum in the close-infrared region light to the lower cell,” they highlighted. “In order to improve light absorption, it is crucial to reduce the undesired losses at the junction resulting from Fresnel surface reflection.”

The scientists used the SCAPS-1D solar cell capacitance software, developed by the University of Ghent, to simulate the novel cell configuration. They assumed the top cell to be built with an n-type cadmium sulfide (CdS) window layer, the CdTe absorber, and a back surface field (BSF) based on molybdenum disulfide (MoS₂). The bottom cell was designed with an n-type CdS window layer, the FeSi2 absorber, and a copper tin sulfide (Cu2SnS3) BSF.

In the simulation, the team considered parameters such as energy bandgap, diffusion length, and doping concentration. “CdTe has featured a 1.5 eV bandgap and a 4.28 eV electron affinity, while the bandgap and electron affinity of FeSi₂ are 0.87 eV and 4.16 eV, respectively,” it specified. “An optimal, slender tunnel junction connecting the upper and lower cells with monolithic architecture has been assumed for the electrical linkage.”

The numerical analysis showed that the top CdTe cell may potentially achieve a power conversion efficiency of 26.13%, while the FeSi₂ bottom cell may reach up to 35.25%. It also demonstrated that the tandem device may achieve an efficiency of 43.91%, an open-circuit voltage of 1.928 V, a short-circuit current of 25.338 mA/cm², and a fill factor of 88.88%.

“These results suggest the practical feasibility of fabricating high-performance CdTe–FeSi₂ double-junction tandem solar cells for efficient solar energy conversion,” the scientists affirmed.

The cell was described in the study “Design and optimization of a high efficiency CdTe–FeSi₂ based double-junction two-terminal tandem solar cell,” published in Heliyon.

From pv magazine global

An international research team led by Germany’s Friedrich-Alexander-Universität Erlangen-Nürnberg has built a large area organic photovoltaic (OPV) panel with a world record efficiency of 14.5%.

The result was certified by the Fraunhofer Institute for Solar Energy Systems (Fraunhofer ISE). For the same module type, the Friedrich-Alexander-Universität Erlangen-Nürnberg achieved an efficiency of 14.46% in December 2023. That result was a jump up from the previous record of 13.1 % recorded for a 57-cell encapsulated module by Taiwan-based OPV specialist, Ways Technical Corporation (Waystech) and Nanobit.

The module relies on 216 individual 4 mm² solar cells. The devices were built with a substrate based on glass and indium tin oxide (ITO), an electron transport layer (ETL) based on zinc oxide (ZnO), an absorber made of an organic material known as PM6:Y6-C12:PC61BM, a hole transport layer (HTL) relying on the polymer PEDOT-F, and a silver (Ag) metal contact.

The group used P1, P2, and P3 laser scribing for building the monolithic interconnections that add voltages between cells in modules. It constructed a module with a size of 143 mm × 143 mm and an active area of 204.11 cm².

The scientists said that, in the cell-to-module scaling up process, there were lower resistive losses thanks to an accelerated blade coating technique that reportedly enabled homogeneous coatings with a thickness deviation of less than 5%. The ETL, the absorber, and the HTL were all blade-coated from non-halogenated solvents in ambient air.

Tested under standard illumination conditions, the module achieved a maximum power conversion efficiency of 15.1% and a fill factor of 76.0%, which the scientists said is the same as that of the individual solar cells used in the panel.

These results should appear soon in the U.S. Department of Energy’s National Renewable Energy Laboratory (NREL) champion PV module efficiency chart. “This work presents cutting-edge upscaling research on OPVs that aims at closing the efficiency gap between high-performance cells and modules,” the researchers said.

The new OPV module was presented in the paper “Large-area organic photovoltaic modules with 14.5% certified world record efficiency,” published in Joule. The research team comprised academics from Germany’s Nuremberg Institute of Technology, Canada-based OPV material supplier Brilliant Matters, and China’s Huazhong University of Science and Technology.

From pv magazine Global

Swedish PV manufacturer First Solar European Technology Center AB, a unit of US-based thin-film solar module producer First Solar, and Uppsala University have presented a new solar cell based on copper, indium, gallium and diselenide (CIGS) technology.

The First Solar European Technology Center was formerly known as Evolar, a company founded in 2019 from now-insolvent CIGS thin-film manufacturer Solibro. It was then acquired by First Solar in May 2023. The company focuses on developing solutions, including manufacturing equipment, to commercialize tandem solar technology with perovskite thin films.

The new solar cell achieved a maximum power conversion efficiency of 23.75% and a certified efficiency of 23.64%, thus beating the previous world record of 23.35% achieved in 2019 by Japan’s Solar Frontier. Germany’s Fraunhofer Institute for Solar Energy Systems (Fraunhofer ISE) confirmed the result.

“We achieved this by combining four different approaches,” the research’s lead author, Jan Keller, told pv magazine. “We added a relatively high concentration of silver to the absorber and implemented a ‘hockey stick’-like gallium (Ga) depth profile. Furthermore, we tailored a rubidium fluoride (RbF) post-deposition treatment (PDT) to the absorber composition and subjected the absorber to extended illumination.”

These processes, according to the research team, were able to improve the microstructure, reduce the defect density and mitigate band gap fluctuations, passivate the absorber surface and increase the doping density. “Overall, this led to a reduced open-circuit voltage deficit, resulting in a high external radiative efficiency of 1.6%,” Keller added.

Presented in the study “High-concentration silver alloying and steep back-contact gallium grading enabling copper indium gallium selenide solar cell with 23.6% efficiency,” which was recently published in nature Energy, the cell was built with a glass substrate coated with molybdenum (Mo), sodium fluoride (NaF) layer, the CIGS absorber, the RbF layer, a cadmium sulfide (CdS) buffer layer, a window layer of zinc oxide (i-ZnO), an aluminum doped zinc oxide (ZnO:Al) film, and an anti-reflective coating based on magnesium fluoride (MgF2).

The scientists explained that they used a relatively high amount of silver in the absorber and placed a ‘hockey stick ’-like gallium profile with a high Ga concentration close to the Mo back contact and a lower, constant concentration in the region closer to the CdS buffer layer. They also applied a standard RbF post-deposition treatment (PDT), which they said allowed to reduce the thickness of the CdS buffer layer to 25 nm.

“Our study demonstrates that CIGS thin-film technology is a competitive alternative as a stand-alone solar cell. The technology also has properties that can function in other contexts, such as the bottom cell of a tandem solar cell,” the research team said.

Looking forward, the scientists said they could raise the cell efficiency to over 25%. This should be achieved by avoiding parasitic absorption in the window and buffer layers, while maintaining the same open-circuit voltage and fill factor levels.  “To go beyond this level, the absorber quality has to be further improved and external radiative efficiency (ERE) values much higher than 1.6% need to be realized to further reduce the open-circuit voltage deficit and the ideality factor,” they concluded.

From pv magazine Global

Researchers from the University of Toledo in the United States have developed a flexible cadmium telluride (CdTe) solar cell based on an indium gallium oxide (IGO) emitter layer and a cadmium stannate (CTO) transparent conductor as the front electrode.

“A sputtered cadmium selenide (CdSe) layer was employed to incorporate Se into a CdTe absorber that was deposited by close-space sublimation, and copper(I) thiocyanate (CuSCN) was used as a hole transport layer between the CdTe and the back metal electrode,” the research’s corresponding author, Manoj Kumar Jamarkattel, told pv magazine. “This device configuration offers great promise for building integrated photovoltaics, space applications, and higher-rate manufacturing.”

The scientists built the cell with a superstrate based on Corning Willow Glass, which is a flexible, ultra-thin glass manufactured by multinational technology company Corning with its own proprietary fusion draw process. They produced the CTO transparent conductor by sputtering in conjunction with a proximity anneal with CdS. The front buffer layer was comprised of an IGO alloy, prepared by co-sputtering.

Furthermore, they prepared the cell absorber by first depositing CdSe by sputtering followed by CdTe deposited by close-space sublimation. CuSCN was used as a Cu doping source and a hole-transporting back-buffer layer. The cell also relies and a gold (Au) metal contact and an anti-reflecting (AR) coating.

Tested under standard illumination conditions, the cell achieved a power conversion efficiency of 17.2%, an open-circuit voltage of 861 mV, a short-circuit density of 27.8 mA/cm2, and a fill factor of 71.7%. Under air mass zero (AM0) illumination for space applications, these values dropped to 14.6%, 861 mV, 32.3 mA/cm2, and 71.2% respectively.

“We used IGO and CuSCN as front emitter and back contact buffer, respectively,” the scientists explained. “This helped to further improve the open-circuit voltage. IGO has favorable band alignment with the absorber, which minimizes carrier recombination at the front, and CuSCN helps to minimize recombination at the back interface.”

The research group added the cell achieved the highest reported device efficiency for flexible CdTe solar cells to date.

The device was presented in the paper “17.2% Efficient CdSe_xTe_1−x solar cell with (In_xGa_1−x)₂O₃ emitter on lightweight and flexible glass,” published in Applied Physics Letters.

The University of Toledo developed several types of CdTe solar cells over the past years. The devices include, among others, a 20%-efficient cell based on a commercial tin(IV) oxide (SnO₂) buffer layer and a 17.4%-efficient device using a layer of copper-aluminum oxide to the rear side of the CdTe thin film.

From pv magazine Global

Researchers at the University of Victoria in Canada have built a flexible perovskite solar cell based on a polyethylene terephthalate (PET) substrate in ambient air fabrication.

They explained that PET is cheaper than commonly utilized polyethylene naphthalate (PEN) in substrates for flexible solar cells, with the latter having however the advantage of being more thermally stable during the production process. PET, by contrast, has a maximum temperature tolerance of 100 C and can tolerate deposition procedures under this threshold.

For this reason, the research group chose a cell architecture with a substrate made of PET and indium tin oxide (ITO), an electron transport layer (ETL) based on tin oxide (SnO2), a methylammonium lead iodide (MAPbI3) perovskite absorber, a Spiro-OMeTAD hole-transporting layer (HTL), and a gold (Au) metal contact.

They deposited the SnO₂  layer by annealing at 100 C, the Spiro-OMeTAD at 50 C, and the perovskite absorber at 100 C by a slot-die coating of acetate/chloride salts. “The acetate component of this ink converts to gas during perovskite deposition process, creating local positive pressure and pushing dust away from deposition area,” they explained. “Deposition of perovskite from this ink requires neither clean rooms nor inert atmosphere. The chloride component, in contrast, improves crystallization dynamics of the film.”

The group built a cell with an active area of 0.049 cm² active area and a reactant known as phenyltrimethylammonium chloride (PTACl). “When adding PTACl into the colloidal solution of SnO₂, we observed doubling the size of agglomerates, which indicates that the phase-transfer agent indeed increased the particle-to-particle interaction in the colloidal solution,” it stated.

Tested under standard illumination conditions, the flexible perovskite device achieved a power conversion efficiency of 17.6%, an open-circuit voltage of 0.95 V, a short-circuit current density of 23 mA cm⁻², and a fill factor of 80%.

The scientists also built a 1 cm² device with the same configuration showing an efficiency of 12.7%, an open-circuit voltage of 0.97 V, a short-circuit current density of 21.7 mA cm⁻², and a fill factor of 60.2%. They said the fill factor loss compared to the smaller device is due to increased resistance of the ITO substrate, which they ensure can be further improved through improved electrode design.

“The incorporation of phase-transfer catalyst, PTACl, into the SnO₂ colloidal solution improved particle-to-particle interaction, enhancing SnO₂ coverage and strengthening the binding to the perovskite layer,” they emphasized, adding that future research should focus on replacing MAPbI₃ with more stable perovskite materials.

The device was introduced in the study “Enhanced Particle-to-Particle Interaction of Tin Oxide Electron Transporter Layer for Scalable Flexible Perovskite Solar Cells,” published in RRL Solar.

From pv magazine global

Heating, ventilation, air conditioning, and refrigeration (HVACR) and water heating products provider Rheem recently launched a new heat pump for residential applications.

“The RD17AZ is ideal for when installation locations are constrained,” the manufacturer said. “But is also perfect for any system or replacement option where an efficient, streamlined look is desired.”

The heat pump uses R-410a as a refrigerant and has a size ranging from 2 tons to 5 tons. The heat pump’s number of tons doesn’t refer to its weight but to the tons of heat a home needs.

The new product measures 1,020 mm x 92 mm x 42 mm. It has reportedly a seasonal energy efficiency ratio (SEER2) of up to 19 and a heating seasonal performance factor (HSPF2) of up to 8.5. It features a rated power of 7.0 kW to 17.6 kW and a cooling capacity spanning from 6.7 kW to 15.5 kW.

The manufacturer also said the heat pump uses a 7 mm condenser coil that reduces refrigerant requirements up to 15%. Sound levels are indicated at 58 dB. “Inverter driven, variable speed, twin rotary compressor technology features fully variable cooling and heating operation between 45% to 100% of capacity,” it further explained.

The system also relies on built-in Bluetooth connectivity through which users can receive alerts on their smartphones with the EcoNet app developed by Rheem itself.

“RD17AZ was rated as 2024’s most efficient, even in cold climates, and works with nearly any HVAC system option or as a universal replacement with minimal alterations required,” the company said.

From pv magazine Global

The world could install up to 574 GW of new PV capacity this year, according to a new global PV outlook report from BloombergNEF. It said that new solar installations hit 444 GW in 2023, significantly surpassing its previous forecast of around 413 GW.

The research firm said it also expects new global PV installations to reach 627 GW in 2025 and 672 GW in 2026, and then grow further to 718 GW in 2027 and 722 GW in 2028. For 2029 and 2030, it predicts annual PV growth of 820 GW and 880 GW, respectively.

These figures diverge substantially from those released by Wood Mackenzie in January. It predicted flat annual average growth over the next eight years, bucking the trend of rapid growth over the last decade.

“The challenge in making forecasts is that if you keep predicting growth at current rates, you end up forecasting the entire world being covered with solar panels,” Jenny Chase, a solar analyst at BloombergNEF, told pv magazine. “Our 2030 forecast is already over 6.7 TW, well above BNEF’s Net Zero Scenario and relatively comparable with global power generation capacity of 8.5 TW at the end of 2022.”

Chase said that Portugal and Greece could generate 50% more electricity from solar by 2030 than they did in 2022.

“At those levels, we will have negative feedback mechanisms, and those are what is really hard to predict,” she added. “Power will already be priced very low when the sun’s out, and storage isn’t free – so why would anyone build more solar, at least at historical rates of growth? That’s what BNEF’s regional analysts have to grapple with now that solar is not small anymore, and it’s no wonder that they can seem like cowards. Forecasting that the future will be dramatically unlike the past is always difficult.”

From pv magazine global

South Korean conglomerate LG has unveiled a new storage system for residential applications. The enblock E system is available in two versions, with usable energy capacities of 12.4 kWh and 15.5 kW.

“With just a few millimeters required on each side, the storage cabinet is not limited in any way when it comes to installation,” the company said in a statement. “Thanks to the IP55 protection class, enblock E can be operated in the cellar as well as in the garage without any problems.”

The system features lithium iron phosphate battery (LFP) cells manufactured by the group’s LG Energy Solutions unit. It is also compatible with inverters from major producers such as Fronius, Kostal, GoodWe and SMA.

The smaller model has a usable energy capacity of 12.4 kWh and a battery capacity of 56.6 Ah. The voltage range is between 180.0 V and 262.8 V, while the nominal voltage is 231.8 V.

The system’s maximum charge-discharge current is 36.5 A and the maximum charge-discharge power is 6.2 kW. The battery pack’s roundtrip efficiency is more than 95%.

The larger product offers a usable energy capacity of 15.5 kWh and the same battery capacity as the smaller product. The voltage range is between 225.0 V and 328.5 V, while the nominal voltage is 289.8 V.

The system’s maximum charge-discharge current is 36.5 A and the maximum charge-discharge power is 7.7 kW. The battery pack’s roundtrip efficiency is more than 96%.

The two different models measure 451 mm x 330 mm, which enables easy deployment in the “furthest” corners, said the manufacturer.

“Owners of a PV system can integrate enblock E on the DC side with a new solar system or retrofit an existing solar system on the AC side,” said LG. “If the originally installed storage capacity is not sufficient, enblock E allows an additional storage module to be retrofitted up to two years after commissioning.”

From pv magazine Global

Scientists at Belgium’s Hasselt University have discovered that climate-based solar module degradation rates could have a significant impact on power electronics in PV systems.

In the study “Assessing the impact of PV panel climate-based degradation rates on inverter reliability in grid-connected solar energy systems,” which was recently published in Heliyon, the academics warned that using similar climate-based degradation rates for PV systems in all climate zones worldwide represents an “unrealistic approximation” that can lead to misleading results. “This can result in the over- or underestimation of PV lifetime and subsequently impact the power electronics reliability estimations,” they added.

The research group evaluated the panel degradation rates based on climatic stresses in three distinct geographical locations: Genk in Belgium, Accra in Ghana, and Kabd in Kuwait. These locations represent moderate, hot and humid, and hot and dry climates, respectively.

It used a physics-based approach that considered meteorological data such as ambient temperature, irradiance, wind speed, and direction, as well as material properties like optical, thermal, and electrical constants, and thicknesses of each layer in the module. It also took into account panel parameters such as temperature coefficients, external quantum efficiency, and interconnect layout.

The researchers explained that insulated-gate bipolar transistors (IGBTs), which are the switching devices in the PV inverter, are extremely sensitive to high temperatures and, without proper management, can lead to failures or reduced lifespan.

“Every time that an IGBT is turned on, there will be power losses generated inside the material layers, and these power losses can generate heat inside the IGBT,” they explained. “Consequently, each activation induces a thermal cycle attributed to these power losses.”

The team analyzed the potential degradation rates in a standard 4 kW PV system including a DC-DC boost converter and a single-phase inverter using four IGBTs with a voltage rating of 700 V and a current rating of 40 A. It considered a scenario without solar module intrinsic degradation rate and a scenario taking into account intrinsic PV degradation rate.

Through a series of simulations, the researchers found that the inverter in the PV system located in Kabd has a much shorter lifespan than inverters located in Genk and Accra.

“The PV inverter in Kabd experiences substantial thermal stresses without the effects of PV degradation, and the IGBT may fail in just 5 years, leading to PV inverter failure in just 3.8 years,” they stressed. “With the introduction of linear PV degradation, the PV inverter’s lifespan in Kabd will increase to 5.8 years, but still falls short of the other two locations. The physics-based PV degradation model will raise Kabd’s lifespan to around 6.5 years.”

The group concluded that deploying PV systems in hot and arid climates could require different parameters for inverter design. “These results demonstrate the importance of incorporating various factors and parameters when assessing the reliability of a PV inverter and its switching device,” it stated.