RT Journal Article ID 09fd46b355f8c528 A1 Zhao, Jiafei A1 Ni, Mingjiang A1 Shou, Chunhui A1 Zhang, Yanmei A1 Wei, Wei A1 Zhang, Jixiang A1 Luo, Zhongyang A1 Cen, Kefa T1 OPTIMUM OPTICAL PROPERTIES OF THE WORKING FLUID IN A DIRECT ABSORPTION COLLECTOR JF Journal of Enhanced Heat Transfer JO JEH(T) YR 2011 FD 2011-05-20 VO 18 IS 3 SP 239 OP 247 K1 photovoltaic/thermal K1 solar cell K1 direct absorption collector K1 inverse method K1 genetic algorithm AB This paper identifies the optimum optical properties of the working fluid used in a combined photovoltaic/thermal system. The system consists of a thermal unit placed in front of a photovoltaic solar cell module. The working fluid of the thermal unit absorbs the infrared solar radiation while the remaining visible light is transmitted and converted into electricity by the solar cell. This arrangement prevents excessive heating of the solar cell which would otherwise negatively affect its electrical efficiency. The optical properties of the working fluid were modeled based on the damped oscillator Lorentz-Drude model satisfying the Kramers-Kronig relations. The coefficients of the model were retrieved by the inverse method based on genetic algorithm, in order to (i) maximize transmission of solar radiation between 200 and 760 nm and (ii) maximize absorption in the infrared part ofthe spectrum from 760 to 2000 nm. The results indicate that the optimum system can effectively and separately use the visible and infrared parts of solar radiation. The thermal unit absorbs 88% of the infrared radiation for photothermal conversion and transmits 84% of visible light to the solar cell for photoelectric conversion. PB Begell House LK https://www.dl.begellhouse.com/journals/4c8f5faa331b09ea,2b8e6bd90598cf19,09fd46b355f8c528.html