Energy
New design improves photovoltaic-thermal efficiency
Researchers in Iran demonstrate that integrating wavy copper cooling tubes into photovoltaic-thermal systems significantly boosts electrical and thermal outputs.
Key points
- Scientists at Razi University tested different copper tube geometries in a water-cooled photovoltaic-thermal collector.
- The optimal configuration, featuring a 200 mm pitch wavy tube, reduced panel temperatures by about 15 degrees Celsius.
- Overall efficiency for the optimal setup exceeded 37 percent, outperforming conventional straight-tube designs.
What happened
Academic researchers at Razi University in Iran have completed an experimental study evaluating how different cooling channel geometries affect the performance of photovoltaic-thermal systems. According to reporting by pv magazine, the team investigated whether mechanically bent wavy copper tubes could extract heat more effectively than standard straight configurations.
The investigators constructed a water-cooled unit utilizing a commercially representative 180-watt photovoltaic module equipped with an aluminum absorber plate. Three distinct copper assemblies were tested: a straight-tube baseline and two wavy designs featuring pitches of 200 millimetres and 300 millimetres, respectively. Outdoor trials were conducted in Kermanshah during May 2025 across water flow rates ranging from 200 millilitres to 800 millilitres per minute.
Implementation of liquid cooling successfully lowered operating temperatures compared with an uncooled module. The configuration featuring the 200-millimetre pitch, designated as W-200, achieved a maximum electrical efficiency of 13.65 percent and a thermal efficiency of roughly 24 percent at the highest flow rate. This configuration delivered an overall system efficiency exceeding 37 percent, compared to approximately 31 percent for the straight-tube setup. The findings were detailed in the journal Energy Nexus.
Why it matters
Improving the efficiency of solar energy capture remains a priority for expanding clean generation capacity across global power markets. While fossil fuel benchmarks remain high, with Brent spot prices recorded at 115.22 US dollars per barrel and Henry Hub gas at 3.1 US dollars per MMBtu in October 2026 according to US Energy Information Administration figures, advancing renewable technology is crucial for long-term grid stability. Although World Bank data indicates that global electricity use per person reached 3,708.5 kilowatt-hours in 2024, many developing regions continue to face energy access challenges.
For energy investors and policymakers in Nigeria and across Africa, innovations in photovoltaic-thermal technology offer a pathway to maximise energy yields in high-temperature environments. High ambient temperatures typically degrade the electrical performance of standard solar panels. By deploying effective thermal management solutions that recover waste heat while boosting electrical output, project developers can improve project economics and accelerate the transition toward sustainable power generation.
Original reporting
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