A Sterling Engine is a closed system. The "hot" side oscillates between higher temperature with higher pressure and lower temperature with lower pressure. Does Nature switch back and forth between one temperature/pressure combination and another temperature/pressure combination without loss of energy within the closed system?
The International Sterling Engine Society says they can get 60 Watts from a 50 degree temperature differential. Is there the equivalent of 60 Watts of power pulled from the hot tank? If not, where does the 60 Watts come from?