Two optical methods of passively reducing the operating temperature of photovoltaic (PV) modules could substantially reduce the total cost of solar installations by extending their lifetimes, according to researchers from Purdue University (West Lafayette, IN) and the National Renewable Energy Laboratory (NREL; Golden, CO).1
In the first method, subbandgap absorption in the semiconductor PV material is reduced by adding a nonabsorbing spectral filter to keep the offending spectral bands from being absorbed by the PV material. The second method consists of enhancing thermal radiation from the PV material to the surroundings by tailoring the spectral emissivity of the PV module.
These alterations can cool nonconcentrated (1-sun) and low-concentrated PV modules by up to 10°C and 20°C, respectively, say the researchers. The result is, respectively, up to a 0.5% and 1.8% efficiency increase and a very large 80% and 260% increase in PV module lifetime.
These results apply for a wide range of semiconductor PV materials, including silicon (Si), gallium arsenide (GaAs), cadmium telluride (CdTe) and copper indium gallium selenide (CIGS).
To come to these results, the researchers did a number of opto-electro-thermal simulations, in addition to accumulating data from previous research efforts.
REFERENCE:
1. Xingshu Sun et al., arXiv:1701.01678v1 [physics.optics]; 6 Jan. 2017.
John Wallace | Senior Technical Editor (1998-2022)
John Wallace was with Laser Focus World for nearly 25 years, retiring in late June 2022. He obtained a bachelor's degree in mechanical engineering and physics at Rutgers University and a master's in optical engineering at the University of Rochester. Before becoming an editor, John worked as an engineer at RCA, Exxon, Eastman Kodak, and GCA Corporation.