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.

From pv magazine global

Fraunhofer ISE researchers have studied how residential rooftop PV systems could be combined with heat pumps and battery storage.

They assessed the performance of a PV-heat pump-battery system based on a smart-grid (SG) ready control in a single-family house built in 1960 in Freiburg, Germany.

“It was found that the smart control increased the heat pump operation by boosting the set temperatures,” researcher Shubham Baraskar told pv magazine. “The SG-Ready control increased the supply temperature by 4.1 Kelvin for hot water preparation, which then decreased the seasonal performance factor (SPF) by 5.7% from 3.5 to 3.3. Furthermore, for space heating mode the smart control decreased the SPF by 4% from 5.0 to 4.8.”

The SPF is a value similar to the coefficient of performance (COP), with the difference it is calculated over a longer period with varying boundary conditions.

Baraskar and his colleagues explained their findings in “Analysis of the performance and operation of a photovoltaic-battery heat pump system based on field measurement data,” which was recently published in Solar Energy Advances. They said the main advantage of PV-heat pump systems consists of their reduced grid consumption and lower electricity costs.

The heat pump system is a 13.9 kW ground-source heat pump designed with a buffer storage for space heating. It also relies on a storage tank and a freshwater station for producing domestic hot water (DHW). Both storage units are equipped with electric auxiliary heaters.

The PV system is south-oriented and has a tilt angle of 30 degrees. It has a power ouput of 12.3 kW and a module area of 60 square meters. The battery is DC-coupled and has a capacity of 11.7 kWh. The selected house has a heated living space of 256 m2 and an annual heating demand of 84.3 kWh/m²a.

“The DC power from PV and battery units is converted to AC via an inverter which has a maximum AC power of 12 kW and a European efficiency of 95 %,” the researchers explained, noting that the SG-ready control is able to interact with the electricity grid and adjust the system’s operation correspondingly. “During the periods of high grid load, the grid operator can turn off the heat pump operation to reduce the grid strain or can also undergo a forced turn on in the opposite case.”

Under the proposed system configuration, PV power must be initially used for the house loads, with surplus being supplied to the battery. Excess power could only be exported to the grid, if no electricity is required by the household and the battery is completely charged. If both the PV system and the battery are not able to cover the house’s energy demand, the electricity grid can be used.

“The SG-Ready mode is activated when the battery is fully charged or is charging at its maximum power and there is still PV surplus available,” the academics said. “Conversely, the trigger-off condition is met when the instantaneous PV power remains lower than the total building demand for at least 10 minutes.”

Their analysis considered self-consumption levels, solar fraction, heat pump efficiency, and the impact of the PV system and the battery on the heat pump performance efficiency. They used high-resolution 1-minute data from January to December 2022 and found that the SG-Ready control increased the heat pump supply temperatures by 4.1 K for DHW. They also ascertained that system achieved an overall self-consumption of 42.9% during the year, which translates into financial benefits for the homeowners.

“The electricity demand for the [heat pump] was covered by 36% with the PV/battery system, through 51% in domestic hot water mode and 28% in space heating mode,” the research team explained, adding that higher sink temperatures reduced heat pump efficiency by 5.7% in DHW mode and by 4.0% in space heating mode.

“For space heating, a negative effect of the smart control was also found,” Baraskar said. “Due to the SG-Ready control the heat pump operated in space heating above the heating set point temperatures. This was because the control probably increased the storage set temperature and operated the heat pump even though the heat was not needed for space heating. It should also be considered that excessive high storage temperatures can lead to higher storage heat losses.”

The scientists said they will investigate additional PV/heat pump combinations with different system and control concepts in the future.

“It must be noted that these findings are specific for the individual evaluated systems and can vary greatly depending on the building and energy system specifications,” they concluded.

From pv magazine global

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

The NB-JD580 double-glass module features 144 half-cut solar cells based on M10 wafers and a 16-busbar design. It features a power conversion efficiency of 22.45% and a power output of 580 W.

The new panels measure 2,278 mm x 1,134 mm x 30 mm and weigh 32.5 kg. They can be used in PV systems with a maximum voltage of 1,500 V and an operating temperature between -40 C and 85 C.

“The panel’s mechanical characteristics make it suitable for different applications, including commercial, industrial and utility-scale installations,” the company said in a statement.

The IEC61215- and IEC61730-certified product has an operating temperature coefficient of -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

Researchers at Switzerland’s ETH Zürich have conducted an extensive analysis on the commissioning timelines of a set of renewable energy projects deployed worldwide between 2005 and 2022 and have found, surprisingly, that completion times increased on average over the past two decades.

The academics investigated, in particular, the timelines of 12,475 projects using PV, wind onshore, wind offshore, biomass, and run-off-river hydropower spread across 48 countries. “The regions are defined as per World Bank country and lending group classification and sorted continently into Organisation for Economic Co-operation and Development (OECD) and non-OECD groups, as those in the OECD group tend to be wealthier countries,” they explained.

Their analysis considered project size, technology, project and developer characteristics, project site, and a project’s related market. They utilized project-level data sourced from Bloomberg New Energy Finance (BloombergNEF) and other country-level data and environmental data from the World Bank, the International Monetary Fund, and the Worldwide Governance Indicators, among others.

“We only considered projects where permitting and commissioning dates are recorded in the data and where a country has at least five transactions for any given technology,” the group specified. “The sourced data include details on installed capacity, names of actors developing the projects, project geocoordinates, permitting dates, and commissioning dates.”

One of the first conclusions drawn by the scientists is that, although PV is the technology that requires the least time to commission, the completion times for the deployment of utility scale solar plants in many countries increased from 2015 to 2022. “The findings further indicate that the mean time for deployment has increased for all technologies in the OECD and non-OECD groupings, except for biomass electricity in non-OECD countries,” they stated.

Referring to the critical factors that may delay projects, the academics said size has an “insignificant” impact and added that developers’ experience is, instead, a significant predictor of commissioning times, although only for PV and wind onshore. “This is likely due to low experience build-up in the other technologies due to relatively low deployment compared to solar PV and wind onshore,” they emphasized, noting that the presence of a domestic developer or a state-owned company may speed up deployment.

The analysis showed that completion times for PV and wind onshore increased by 0.5 years and 0.9–1.2 years respectively for OECD and non-OECD countries. “The upward trend also holds for different regions within the OECD and non-OECD groupings, with only Europe and Asia-Pacific showing a reduction in commissioning times for small hydro RoR and biomass electricity respectively,” the researchers noted.

The analysis also showed that factors such as currency devaluation and GDP contraction, as well as the COVID-19 crisis, had a significant impact on project timelines. It also showed that the average project size for solar PV during the 2005-2022 period is 17.3 MW in OECD countries and 34.4 MW in non-OECD countries.

The research group presented its findings in the study “A global analysis of renewable energy project commissioning timelines,” published in Applied Energy. “Future research could strengthen the econometric analysis with other potential factors and variables, and potentially apply them to energy technologies beyond renewables, such as electricity storage or grid assets, which might shed light on the robustness of our framework,” the scientists concluded.

From pv magazine global

Industrial conglomerate Johnson Controls introduced a water-to-water screw heat pump intended for use in small commercial buildings and district heating.

The company said its new York YVWH Water-to-Water Dual Variable Speed Screw Heat Pump is the first of its kind using the R-1234ze refrigerant in North America.

“R-1234ze is a refrigerant with an ultra-low global warming potential (GWP) of 1, enabling the YVWH to go considerably beyond the refrigerant regulations that go into effect starting January 1, 2025, as currently proposed by the U.S. Environmental Protection Agency,” the company said in a statement.

The new product is currently available in a version with a 200-ton cooling capacity. It offers 703 output for cooling and 1,186 kW for heating.

The company said the system has a combined coefficient of performance of 4.1. It may also use the R-515b refrigerants and can reportedly provide a water temperature of up to 176 F or 80 C, which the manufacturer is the highest ever reached for screw heat pumps.

“At that temperature, the unit can provide 4,050 thousand British thermal units (BTUs) per hour of heating while simultaneously providing 200 tons of chilled water cooling at 5 C,” the manufacturer said. “The YVWH also features variable-speed drive and has excellent turndown that allows it to run with as low as 25% of the design-heating load.”

The heat pump can be operated for heating or cooling separately or for simultaneous heating and cooling.

Switzerland’s Meyer Burger Technology has announced that it is preparing to shut down its solar module manufacturing facilities in Germany.

“With a deteriorating market environment in Europe, continuing with full-scale European solar manufacturing is not sustainable for the time being,” the company said in a statement. “Part of the plan would unfortunately be the closure of one of Europe’s largest operational solar module production sites in Freiberg, Germany, as early as beginning of April 2024, affecting approximately 500 people.”

The company said that it will make a final decision by the end of February, leaving the door open to rethink its plan if “sufficient measures to create a level playing field in Europe, such as a resilience-reward scheme,” are put into place.

Meyer Burger said that cell production at its factory in Talheim, Germany, will support module production at its 2 GW factory currently under construction in the United States.

“The R&D sites in Switzerland and Germany would not be affected by these measures and continue to develop and produce technology and equipment to support Meyer Burger’s business outside Europe,” it said.

“In the US, we can take full advantage of our leading technology position, resulting in substantial interest by partners and supported by favorable industry policies,” said Meyer Burger CEO Gunter Erfurt. “The expansion of the U.S. business is currently proceeding as planned with the ramp-up of our solar module production site in Goodyear, expected to start in the second quarter of 2024.”

By combining US module and cell manufacturing, Meyer Burger will benefit from the Advanced Manufacturing Tax Credit 45X system, which is a component of the US Inflation Reduction Act (IRA).

Prior to this announcement, Meyer Burger was targeting around 3 GW of new annual production capacity in Germany by the end of 2024, including 1.4 GW of module production capacity in Freiberg. It also currently plans to build a 3.5 GW solar cell and module factory at an unspecified location in Spain.

From pv magazine Global

A group of scientists from the Hungarian University of Agriculture and Life Sciences designed a prototype of a solar photovoltaic tree that purportedly offers an optimal balance between energy production and thermal management.

The key feature of the system is a larger distance between the solar modules compared to conventional solar tree designs. This approach is intended to reduce shading losses between the panels while improving cooling and heat dissipation.

The prototype has a total diameter of 660 mm and relies on solar modules based on cells provided by Shenzhen Xiangxinrui Solar Energy Co., Ltd. China. Each panel has a size of 180 mm x 60 mm x 3 mm and an efficiency of 22%.  The solar tree also relies on a stem measuring 1800 mm in height and a flat wooden sheet segmented into fifteen branches.

In order to validate the proposed design, the scientists compared its performance with that of a flat PV system with the same characteristics. “Both the solar tree and the flat module were integrated and configured within the same electrical circuit, featuring six rings connected in parallel,” the scientists explained. “Each ring consisted of three modules connected in series, resulting in a total of eighteen PV modules.”

Both the solar tree and the flat PV system were tested with a south orientation and tilt angles of 20, 30 and 45 degrees.

The tests revealed that with the 45-degree angle the solar tree recorded a maximum temperature of 49.8 C and the flat system had 38.05 C. As a result, the solar tree configuration yielded a maximum power output of 14.54 W, while the flat system produced 11.8 W.

Under the 30-degree tilt angle configuration, the flat system reached a temperature of 51.3 C and the solar tree reached 40.75 C. The latter achieved a maximum power output of 13.84 W, compared to 11.05 W for the flat system. With the 20-degree tilt angle, the solar tree reached a maximum temperature of 33.95 C and the flat system of 43.86 C. The former produced 14.05 W and the latter 11.4 W.

“Empirical results indicate that the flat PV module’s temperature exceeds the solar tree’s by over 10 C, owing to the less efficient convective heat transfer,” the academics stated, adding that the temperatures of the ground shaded by the solar tree were reduced by 3–7 C compared to the unshaded ground. “The efficiency of the solar module configuration proposed herein witnessed an increment of 16–23 % relative to the flat module.”

The researchers also observed that the solar tree offers a land footprint reduction of 96 % compared with the conventional PV systems.

“An examination of the ground footprint revealed that the sunflower PV module afforded 85 % land savings relative to the flat PV module,” they stated. “The area under the solar PV tree can be used for parking and agriculture purposes.”

Their findings were presented in the study “Sunflower solar tree vs. flat PV module: A comprehensive analysis of performance, efficiency, and land savings in urban solar integration,” published in Results in Engineering.

Researchers from the Korea Maritime Institute recently proposed the use of solar trees to build photovoltaic plants in mountainous forest areas in land-scarce South Korea. They defined the new concept as forest-photovoltaic and explained that it would both maintain carbon absorption activities under the solar trees and produce solar power on the upper part of forest land.

Other researchers from Amity University, Noida, in the Indian state of Uttar Pradesh, recently developed four different designs for solar photovoltaic trees that purportedly require less physical space than conventional PV systems in urban environments.

From pv magazine global

The U.S.-based industrial conglomerate Johnson Controls introduced a water-to-water compound centrifugal heat pump intended for use in commercial buildings.

The York Cyk heat pump is designed for high-head conditions and can reportedly deliver high-temperature hot water as high as 170.6 F (77 C).

“The York Cyk can reduce water and operational costs by as much as 50% when compared to traditional boiler and chiller applications,” the manufacturer said in a statement.

The new product is currently available in a small version with a 400-ton cooling capacity. It offers 1,406 kW if output for cooling and 2,051 kW for heating.

The company said the system has a combined coefficient of performance of 4.9. It may use either the R-1234ze or the R-515b refrigerants, which Johnson Controls said have ultra-low global warming potential (GWP).

The heat pump also features two electric motor-driven centrifugal compressors arranged in series and double bundle condenser technology that can cope with unbalanced load conditions, according to the company.

“The innovative design is compatible with existing high-temperature hot water heating systems, eliminating the need to replace air handlers and terminal heating devices, which is often required to accommodate the lower water temperatures associated with other heat pump products,” said the company.

Johnson Controls plans to launch a second version of the heat pump with a 2,000-ton cooling capacity and an output of 7,033 kW at an unspecified later stage.

“The York Cyk heat pump is ideal for medium to large commercial buildings, university campuses, hospitals, industrial processes and district energy applications and can be used in new building or retrofit applications,” it said. 

From pv magazine global

Researchers at the Multiphysics Interaction Lab (MiLab) in the Los Angeles have developed a new photovoltaic-thermal (PVT) system design that uses waste heat from PV panels to generate residential hot water systems.

The system is based on parallel water pipes that are attached to the backside of the solar panels and reduce their operating temperatures. “Our study introduces a simple and practical cooling approach that enhances the electrical efficiency of PV panels while simultaneously offering a sustainable solution to residential hot water needs,” the scientists said.

The experimental system relies on a south-oriented 250 W polycrystalline PV panel with a temperature coefficient of -0.45%/C and a tilt angle of 30 degrees. The copper cooling pipes are connected via upstream and downstream headers and are covered by an aluminum cover to secure them to the backside of the PV panel.

The experimental setup includes a hot water storage tank and an 11 W centrifugal pump that maintains a constant flow rate of 3 L/min.

“The water flow rate is monitored using a flowmeter,” the scientists explained. “To gather accurate data, a set of thermocouples is strategically placed to simultaneously measure various temperatures, including the inlet and outlet water temperatures of the PV/T system, the PV panel’s surface temperature, and the ambient air temperature.”

The system also uses a multimeter to measure the PV module’s output power and a pyranometer to assess solar radiation.

The academics compared the performance of the cooled PV panel to a reference panel without cooling during May at the Notre Dame University-Louaize campus, located in Zouk Mosbeh, Lebanon.

Their analysis showed that the PVT panel can generate 4% more power than the PV module, thanks to the cooling effect of the copper pipes. They also warned, however, that a saturation effect related to the hot water stored in the tank not being effectively utilized, may limit the ability to optimally cool the PV modules at a certain stage.

“This reduction is likely due to the absence of residential water demand in the waste heat recovery system,” the researchers further explained. “This absence causes the cooling water temperature in the hot water reservoir to gradually increase, reducing thus the rate of heat removal from the PVT system.”

The tests also showed that the PVT panel achieved an average electric efficiency of 11.5% while the PV panel without cooling reached an average efficiency of 10%. The scientists also revealed that the PVT system’s total efficiency reached around 75% and that of the reference PV system was only about 10%.

“The average thermal efficiency, representing the ratio of recovered waste heat to the solar energy absorbed by the PV panel, was approximately 60% in the cooled PV/T system,” they also stated. “The cooled PV/T system not only generated a higher fraction of electric power but also exhibited an approximately 40% higher rate of heat loss from the back side of the PV module, indicating the efficient waste heat recovery.”

The system was presented in the paper “An experimental analysis of a hybrid photovoltaic thermal system through parallel water pipe integration,” published in the International Journal of Thermofluids.

From pv magazine global

Terravis Energy, a subsidiary of Canadian technology company Worksport Ltd., has presented a prototype of a residential air source heat pump intended for use in heating and cooling applications.

“Our heat pump utilizes the phase change of a proprietary fluid to transfer heat,” the company’s CEO, Lorenzo Rossi, told pv magazine. “The prototype is currently undergoing testing in Worksport’s climate chamber in Toronto.”

The company conducted tests at its facility in Ontario to monitor the system performance across a range of 12 temperature points from -10 C to -35 C. It also tested refrigerant pressure zones, airflow, and the energy consumption of all heat pump components. Furthermore, it said conventional heat pumps on the market are not efficient at providing sufficient comfort levels at temperatures under -20 C.

“Our heat pump’s goal is to provide heat to homes in as low as -35 C, which we believe will make us the most effective heat pump technology in the market,” Rossi added.

The heat pump showed a coefficient of performance (COP) of around 1.8 and a seasonal coefficient of performance (SCOP) of approximately 3.0. “It’s essential to note that these values are influenced by our local climate conditions and might differ in other regions”, Rossi explained.

The prototype is currently using R32 refrigerant, which has a global warming potential (GWP) of 675, which the company said aligns with the new mandate for 2024 requiring refrigerants to have a GWP of 750 or less in Canada.

The company also said the heat pump system doesn’t utilize expensive electric resistance heating.

“The price of the Terravis Energy heat pump is expected to align with current market offerings, though it might be slightly higher, in the range of $1,000 to $2,000,” Rossi stressed. “This increase can be attributed to the advanced technology and AI software embedded in the motherboard, as well as the inclusion of new hardware components, which contribute to its advanced features and capabilities.

From pv magazine Global

The international research group led by Professor Martin Green from the University of New South Wales in Australia has published Version 63 of the “solar cell efficiency tables” in Progress in Photovoltaics.

The scientists said they have added six new results to the new tables since June.

One of the six results added to the tables is the 25.2% efficiency that researchers at Northwestern University in the United States achieved for a 1-cm² lead halide perovskite cell.

Furthermore, the tables now include the 22.4% efficiency that US-based First Solar achieved for a 0.45 cm² cadmium-telluride (CdTe) cell, the 26.1% efficiency that China’s University of Science and Technology of China (USTC) obtained for 0.05 cm² Pb-halide perovskite solar cell, and the 26.1% efficiency the Northwestern University and the University of Toronto in Canada achieved for a 0.05-cm2 Pb-halide perovskite solar cell.

The fifth result added to the tables is the 36.1% efficiency that Germany’s Fraunhofer Institute for Solar Energy Systems (Fraunhofer ISE) and Dutch research institute AMOLF achieved in September for a multijunction solar cell based on silicon and III-V semiconductors such as gallium indium phosphide (GaInP) and gallium arsenide (GaAs).

The sixth result is the 33.9% efficiency the Chinese module maker Longi announced for a perovskite-silicon tandem solar cell in early November.

In Version 62 of the tables, released in June the researchers added 21 new results, a record number for the Tables. 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, the US Department of Energy, and the US National Renewable Energy Laboratory.