International Journal of Energy Research, Vol.43, No.10, 5526-5534, 2019
Maximum efficiencies and parametric optimum designs of concentrating photovoltaic cell/heat engine systems with three-band spectrum split
The irreversible model of a concentrating photovoltaic cell/heat engine system with three-band spectrum splitting is established for the further prediction of the conversion efficiency of photovoltaic/thermal systems, in which the internal and external irreversible losses are considered. An update efficiency of the spectrum splitting system is derived, from which the maximum efficiency of the whole system is calculated. The influences of the area ratio of two subsystems on the systemic performance are analyzed in detail. The reasonable ranges of the area ratio are given. The maximum efficiency and the corresponding critical parameters are obtained under different operating conditions. It is found that the introduction of the area ratio is significant for accurate predictions of systemic performances and the maximum efficiency can attain 77.64%, which significantly exceeds that of an individual concentrating photovoltaic cell and solar-driven heat engine at the same concentration condition. The performance characteristics of the two-band spectrum splitting system including the photovoltaic cell and heat engine may be directly obtained from the present model. Moreover, the performances of three- and two-band spectrum splitting systems are compared, and consequently, the advantages of the three-band spectrum splitting system are revealed.