Thermoelectronic conversion of solar energy and heat into electric power

Electric power may, in principle, be generated in an efficient manner from focused solar irradiation or chemical combustion by thermionic energy conversion. As the efficiency of this process is degraded by space charges, the efficiencies of thermionic generators have amounted to only a fraction of those fundamentally possible. We show that this space-charge problem can be resolved. Although the technical development of such thermoelectronic generators will require substantial efforts, we conclude that highly efficient transformation of heat into electric power may be achieved.