Thermodynamic optimization of non-concentrating hybrid solar converters

A model of a hybrid solar converter proposed by Goetzberger et al was used to optimize the overall efficiency of the combined system in two different situations. Firstly, the original semi-empirical models for the solar cell and the thermal engine were used. Secondly, more general theoretical models were proposed for each of the two components of the combined converter. The theoretical model of the solar cell produces results in good agreement with the simple empirical model when the ideal cell with no reflection losses is considered. Both the theoretical model and the empirical model of the thermal engine give similar results in the range of temperatures allowed for the proper usage of a solar cell. Reasonable low optimum temperatures could be reached by using materials with a band gap of less than 2 eV. Some ways of improving the hybrid solar converter model proposed by Goetzberger et al are discussed at the end of the paper.