An overview of advanced space/terrestrial power generation device: AMTEC

Alkali metal thermal electric converter (AMTEC) technology offers several advantages over conventional forms of electric generation. Some of these advantages are high efficiency, high density, reliability, absence of moving parts, and competitive manufacturing costs. These and other advantages make AMTECs ideally suited for several space, aerospace, military and domestic applications. Current AMTEC designs suffer from some drawbacks that need to be rectified if the full potential of the technology is to be realized. These are current cell efficiencies that are still at values below the theoretically possible, and the adverse power–time characteristic of the cell. The PX-3A AMTEC cell, for instance, shows decreasing values of the maximum power output with time. Maximum power decreases from 2.54 W at the end of 172 h to 1.27 W at 18,000 h of cell operation. This latter problem, called power degradation, in particular, will preclude the use of the cell for applications that require operation of the cell for long periods of time. This paper discusses in detail the advantages of AMTEC technology and the problems with current designs. In particular, the problem of power degradation is dealt with in some detail and some measures are suggested that will help arrest this loss of power with time.