Physical significance of thermodynamic restrictions on solar energy conversion efficiency

Widespread attempts are currently being made to find ways of directly converting solar energy into chemical energy. In order to assess the potential of such conversion, it is important to know the maximum values achievable for the solar energy conversion efficiency (CE), n = ..delta..G/E, i.e., the ratio of the stored free energy ..delta..G (or the useful work obtained) to the total solar energy E lost in the conversion.