Thermodynamic theory of thermophotovoltaic solar energy conversion

The thermophotovoltaic (TPV) efficiency is maximized by using three optimization parameters, namely, the absorber and PV solar cell temperatures and the voltage across the cell. Various combinations of spherical and (disk) plane absorbers and solar cells are analyzed. The best performance is associated with a combination plane absorber–plane solar cell. The thermal design has a significant influence on the optimum PV cell band gap. In the case of a normal thermal design, the cell temperature is usually high and depends strongly on the band gap. When a very good thermal design is considered, the optimum cell temperature is less than 30 degrees higher than the ambient temperature and decreases with an increase in the band gap. Increasing the ratio rA/rc between the absorber and PV cell radii leads to increased TPV efficiency. The optimum absorber temperature (practically) does not depend on rA/rc.