A detailed di cussion is presented f the two dynamic ther al converters which appear most useful in future power systems in the next decade, the Stirling engine and the Rankine cycle turbine. Empirical and theoretical equations are presented describing engine performance, and estimates are made of future performance possibilities with new working fluids, higher operating temperatures, etc. Also discussed are electrostatic and electromagnetic generators which are coupled wi h the dynamic thermoconverters. Anticipated weights, efficiencies and other performance characteristics are described. (Author).