Experimental performance of an ultra-low-cost solar photovoltaic-thermal (PVT) collector using aluminum minichannels and nonimaging optics. (15th June 2020)

• Record Type: Journal Article
• Authors: Widyolar, Bennett; Jiang, Lun; Brinkley, Jordyn; Hota, Sai Kiran; Ferry, Jonathan; Diaz, Gerardo; Winston, Roland
• Is Part Of: Applied energy. Volume 268(2020)
• Publication Date: 2020-06-15
• Subjects: Solar -- Photovoltaic -- Thermal -- Hybrid -- PVT -- Nonimaging -- Minichannel; Power (Mechanics) -- Periodicals; Energy conservation -- Periodicals; Energy conversion -- Periodicals; 621.042
• DOI: 10.1016/j.apenergy.2020.114894
• Languages: English
• ISSNs: 0306-2619

Abstract

Highlights: New low-cost PVT collector using nonimaging optics and aluminum minichannels. 1.2 m 2 prototype demonstrated 57.4% thermal, 12.3% electric efficiencies. Expected generation ~226 kWh electric + 603 kWh thermal/m 2 /year. Module costs $81/m 2 and avoids 1280 kWh natural gas and 183.8 kg CO2/m 2 /year. 85% capital cost and 70% roof space compared to side by side PV + T. Abstract: Electricity, space heating, and hot water are ubiquitous needs among modern buildings. Solar photovoltaic/thermal (PVT) technologies are well suited to provide all of these in a distributed and renewable manner, however, the high cost of current PVT technologies remains a major barrier to implementation as the technology competes for roof space with low cost standalone PV modules. In an effort to reduce costs, a new type of solar PVT collector has been developed which replaces the traditional packaging materials with a low cost nonimaging optic and replaces sheet-and-tube heat exchange materials with a low cost and thermally efficient aluminum minichannel. A 1.2 m 2 aperture prototype built using silicon SunPower solar cells has demonstrated 57.4% thermal efficiency and 12.3% electric efficiency at ambient temperature and a maximum (stagnation) temperature around 80 °C. Extrapolating this performance shows the PVT collector will to generate 226 kW-hours (kWh) of electricity and 603 kWh of heat per square meter each year for a solar resource of 5.5 kWh/m 2 /day, and by doing so avoid 1280 kWh of natural gas consumption and 183.8 kg of CO2 emissions. Technical performance is comparable with commercial PVT systems today, but with a much lower estimated module cost of $81/m 2 ($0.54/WDC ). A side-by-side analysis indicates the PVT collector can be installed for 85% of the capital cost of side-by-side PV + T with only 70% of the required roof space.