Practical efficiency limits of solar cells for space applications

Abstract

Practical efficiency limits are established for solar cells for space applications. Starting from the detailed balance approach that has been implemented in the open source code “etaOpt” input parameters are adjusted in order to reproduce practical efficiencies of current record cells. It will be shown that for solar cells for space applications a natural limit under non-concentrated air mass zero conditions and 25°C lies around 40%. This value can be achieved with solar cells with more than four junctions and optimum bandgap combinations. An assessment of the current cell designs suggested for the next generation space solar cell is given showing that for all concepts efficiencies at beginning of life of above 35% are feasible.