High temperature operation of two-junction photovoltaic converters

Multijunction solar cells can have important application in combined photovoltaic/thermal systems. Over one-third of industrial process heat is used at temperatures below 400° K. Optimized two-cell photovoltaic converters are predicted to have efficiencies up to 39 percent at 300° K and up to 29 percent at 450° K, thus maintaining high efficiencies at temperatures compatible with thermal applications. Operating the cells independently rather than in series provides no major gain in efficiency except where the cells would operate at different temperatures.