Researchers in Iraq have developed biomimetic leaf vein–inspired fins for photovoltaic panels, with reticulate (RET) venation reducing panel temperature by 33.6 C and boosting efficiency by 18% using passive cooling. Their study combines 3D CFD simulations and electrical evaluations to optimize fin geometry, offering a sustainable alternative to conventional cooling methods.

A research group from Iraq’s Al-Furat Al-Awsat Technical University has numerically investigated the thermal and electrical performance of PV panels integrated with leaf vein–inspired fins. They have simulated four types of venation used by plants, namely pinnate venation (PIN), reticulate venation (RET), parallel venation along the vertical axis (PAR-I), and parallel venation along the horizontal axis (PAR-II).

“The key novelty of our research lies in introducing and systematically optimizing biomimetic leaf vein–inspired fin geometries as passive heat sinks for photovoltaic panels,” corresponding author Yasser A. Jebbar told pv magazine. “While conventional cooling approaches rely on simple straight fins, fluids, or active systems, our study is among the first to directly translate natural leaf venation patterns—particularly RET structures—into manufacturable backside fins specifically tailored for PV thermal and electrical performance.”

The team combined detailed 3D computational fluid dynamics (CFD) modeling with electrical efficiency analysis to identify geometries that maximize heat dissipation without additional energy input or water consumption. Next steps include experimental validation of the leaf vein fin designs under real outdoor conditions, particularly in hot climates.

The simulated PV panel consisted of five layers: glass, two ethylene-vinyl acetate (EVA) layers, a solar cell layer, and a Tedlar layer, with a copper heat sink and fins attached. All fin configurations were initially 0.002 m thick, 0.03 m high, and spaced 0.05 m apart. Panels measured 0.5 m × 0.5 m, with a surrounding air velocity of 1.5 m/s and incident irradiance of 1,000 W/m².

RET fins outperformed all other designs, reducing operating temperature by 33.6 C and increasing electrical efficiency from 12.0% to 14.19% —an 18 % relative improvement—compared to uncooled panels.

“This temperature reduction rivals, and in some cases exceeds, water-based or hybrid cooling methods, despite relying solely on passive air cooling,” Jebbar noted. The study also highlighted the significant impact of fin height, more than spacing or thickness, on cooling performance.

The team further optimized the RET fins, varying spacing from 0.02–0.07 m, height from 0.02–0.07 m, and thickness from 0.002–0.007 m. The optimal geometry—0.03 m spacing, 0.05 m height, and 0.006 m thickness—achieved the maximum 33.6 C temperature reduction and 18% efficiency gain.

The novel cooling technique was described in “Improving Thermal and Electrical Performance of PV Panels Using Leaf Vein Fins,” published in Solar Energy. Researchers from Iraq’s Al-Furat Al-Awsat Technical University, University of Kerbala, and Sweden’s University of Gävle have participated in the study.

Scientists have grown organic romaine lettuce under 13 different types of PV modules, in an unusual hot Canadian summer. Their analysis showed lettuce yields increased by over 400% compared to unshaded control plants.

A research group from Canada’s Western University has investigated the performance of organic romaine lettuce, a heat-sensitive crop, under a broad range of agrivoltaic conditions. The test was conducted in London, Ontario, in the summer of 2025, during which 18 days had temperatures over 30 C.

“Our study explores how agrivoltaic systems can be tailored to optimize crop growth, especially under extreme heat conditions, while contributing to sustainable energy generation,” corresponding researcher Uzair Jamil told pv magazine.

“This becomes especially relevant in the context of climate change, where we are experiencing temperature extremes across the world,” Jamil added. “We examined the performance of organic romaine lettuce under thirteen different agrivoltaic configurations – ranging from crystalline silicon PV to thin-film-colored modules (red, blue, green) – in outdoor, high-temperature stress conditions.”

More specifically, the experiment included c-Si modules with 8%, 44% and 69% transparency rate; blue c-Si modules with transparency of 60%, 70%, and 80%; green c-Si modules with transparency of 60%, 70%, and 80%; and red c-Si modules with transparency of of 40%, 50%, 70%, and 80%.

All agrivoltaics installations had a leading-edge height of 2.0 m and a trailing-edge height of 2.8 m, and the modules were oriented southwards at 34◦. Pots with organic romaine lettuce were placed under all configurations, along with three pots fully exposed to ambient sunlight without shading, used as controls.

In addition to measurements against the control, the scientific group has compared the results to the national average per-pot yield for 2022, which included less high-temperature days and was therefore considered typical. Those data points were taken from agricultural census data, which later enabled the researcher also to create nationwide projections of their results.

“Lettuce yields increased by over 400% compared to unshaded control plants, and 200% relative to national average yields,” Jamil said about the results. “60% transparent blue Cd-Te and 44% transparent crystalline silicon PV modules delivered the highest productivity gains, demonstrating the importance of both shading intensity and spectral quality in boosting plant growth.”

Jamil further added that if agrivoltaic were to scale up to protect Canada’s entire lettuce crop, they could add 392,000 tonnes of lettuce.

“That translates into CAD $62.9 billion (USD $46.6 billion) in revenue over 25 years,” he said. “If scaled across Canada, agrivoltaics could also reduce 6.4 million tonnes of CO2 emissions over 25 years, making it a key player in reducing the agricultural sector’s environmental footprint.”

The results of the research work were presented in “Enhancing heat stress tolerance in organic romaine lettuce using crystalline silicon and red, blue & green-colored thin film agrivoltaic systems,” published in Solar Energy.

Cubenergy has launched FlexCombo 2.0, a scalable battery energy storage system for utility, commercial, and industrial applications, offering up to 16 MWh capacity with LFP batteries. Its modular design, advanced BMS, and cloud-based operations enable easy installation, seamless expansion, and efficient grid integration, according to the manufacturer.

Cubenergy, a Chinese manufacturer of battery energy storage systems (BESS), has introduced a new energy block designed for utility, commercial, and industrial (C&I) applications.

The product, named FlexCombo 2.0, uses the company’s 835 kWh FlexCombo D2 batteries. It is available in three configurations: 10, 12, or 12 batteries, providing a total capacity of 8 MWh, 10 MWh, or 16 MWh, respectively.

“With the FlexCombo D2 modular design and parallel architecture, FlexCombo’s core advantage lies in its long-term scalability,” the company said in a statement. “It enables seamless capacity growth and effortless integration with power generation systems (PGS), simplifying deployment and accelerating delivery for ultimate flexibility.”

The FlexCombo D2 batteries feature lithium iron phosphate (LFP) chemistry, offering a lifespan of 8,000 cycles at 70% capacity retention, according to the manufacturer.

Each battery measures 2 m x 1.68 m x 2.55 m and has a weight of up to eight tons. They carry an IP55 protection rating. Each block also comes with a power conversion system (PCS) rated at 430 kW AC with an IP66 protection grade. Optional medium-voltage (MV) transformers are available, with AC power ratings of either 8,800 kVA or 5,250 kVA.

“The FlexCombo 2.0 is designed primarily for utility and C&I applications, including renewable energy arbitrage, stand-alone grid stabilization, factories, and commercial buildings,” the company stated. “This integrated, easy-to-install BESS can be quickly connected and aligned with project requirements, while the advanced Active Balancing battery management system (BMS) and cloud-based operations provide a superior user experience.”

The South Korean giant said its new EHS All-in-One provides air heating and cooling, floor heating, and hot water from a single outdoor unit. It can supply hot water up to 65 C in below-zero weather.

South Korean tech giant Samsung has launched a new all-in-one heat pump for residential and commercial use.

Dubbed EHS All-in-One, the system provides air heating and cooling, floor heating, and hot water from a single outdoor unit. It is initially released for the European market, with a Korean rollout expected within a year.

“It delivers stable performance across diverse weather conditions. It can supply hot water up to 65 C even in below-zero weather and is designed to operate heating even in severe cold down to -25 C,” the company said in a statement. “The system also uses the R32 refrigerant, which has a substantially lower impact on global warming compared with the older R410A refrigerant.”

The product is an upgrade to the EHS Mono R290 monobloc heat pump that the company released in 2023. The company has enlarged the propeller fan and used a high-capacity motor in the novel model, reducing the number of fans from two to one. That results in a design with a height of about 850 mm, approximately 40% lower than before.

“The system also introduces a new Heat Recovery feature, which does not release waste heat from the cooling process to the outside but recycles it. Using this feature can boost the energy efficiency of water heating by more than twice under certain conditions,” Samsung added. “It also includes an ‘AI Saving Mode’ that can reduce energy consumption by up to 17%.”

With silver prices rising, more large solar manufacturers are expected to switch to copper for cell metallization. Radovan Kopecek of ISC Konstanz tells pv magazine that he expects the entire industry to follow. Ning Song of the University of New South Wales says a small efficiency tradeoff may be acceptable if the cost savings are significant and do not introduce new reliability risks.

The recent surge in silver prices has eased slightly, with prices per troy ounce now just below the all-time high of over $94 per troy ounce reached earlier this week. Following announcements by Chinese module manufacturer Longi announced that it is moving toward copper-based metallization, and by China-based metallization paste supplier DK Electronic Materials that a gigawatt-scale customer will adopt its high-copper paste for commercial production, 2026 could mark a key milestone in the PV industry’s phase-down of the costly metal.

“I do think that the industry will follow in those footsteps, as the PV industry is a ‘follower industry.” When the big players start with something, the others follow,” Radovan Kopecek, the co-founder and director of German research institute the International Solar Energy Research Center Konstanz (ISC Konstanz), told pv magazine. “An immediate transition to copper is technically and economically feasible. Copper screen printing can be implemented quickly, and we have received many inquiries about it.”

According to Kopecek, project developers are “absolutely” ready to embrace copper-metallized products, adding that when the technology is properly implemented, performance does not differ from that of silver-metallized modules. “However, I do not expect the industry to abandon silver completely,” he said. “Silver will remain at around 2 mg to 3 mg per watt, as it is still needed for firing through, as a diffusion barrier, and to establish contact with the emitter.”

Ning Song, from the University of New South Wales (UNSW) in Australia, explained that even if adopting a high-copper paste results in a small efficiency drop, the price trade-off should be acceptable to manufacturers. “That trade-off is acceptable if it does not introduce new reliability risks. Ultimately, the decision depends on how well the efficiency loss can be offset at the module and system level,” she told pv magazine.

Song's team is currently working to identify practical pathways to reduce silver usage in PV cells, both through incremental improvements to existing screen-printed metallization and longer-term exploration of alternative paste systems. “In the short term, aggressive silver thrifting within existing screen-printing processes is the most commercially ready option, as it minimizes disruption to current manufacturing lines,” she stated.

“From a purely technical perspective, the most promising long-term solution is the one that delivers the best combination of low contact resistance, minimal recombination losses at the contacts, high conductivity, sufficient ductility to enable narrow, well-shaped gridlines with reduced optical shading, and robust long-term reliability,” she said. “That is regardless of the specific metal used.”