Experimental and Systems Studies of the Alkali Metal Thermoelectric Converter for Aerospace Power

This is the authors' abstract. We don't add key points for this paper.

The alkali metal thermoelectric converter (AMTEC) is a thermally regenerative electrochemical device for the direct conversion of heat to electrical energy. It is characterized by high potential efficiencies and no moving parts, which makes it a candidate for space power applications. This paper presents a review of AMTEC operating principles and characteristics showing that device conversion efficiencies of 15-40% may be achievable. Experimental voltage vs current curves are presented where power densities of 0.7 W/cm are observed. Measured electrode efficiencies of up to 40% that confirm the high potential efficiencies of the AMTEC are presented. Also shown are the results of preliminary radiation heat-transfer measurements, data that can be utilized to study methods for reducing parasitic radiation losses in the AMTEC. Finally, the results of a preliminary design study are presented showing that by incorporating the AMTEC into existing space power system designs, conversion efficiencies of 15-20% may be achieved at specific powers of 14-17 We/kg in a small power system (800 W). Similar performance is also predicted for a much larger («360 kW) nuclear electric system.