Ian S C wrote:Tom I have run my LTD motor on ice, the ambient temperature was 20*C, so there was a 20* (a little less) temperature differential. The but is the amount of energy required to make the ice.
You certainly make a valid point. Energy is required to make ice in the first place of course. As quoted above, Tesla's reasoning was:
"We would thus produce, by expending initially a certain amount of work to create a sink for the heat to flow in, a condition enabling us to get any amount of energy without further effort."
In otherwords, Yes it requires energy to make ice and ice is needed to get the engine started, but once started, the engine is then being powered by, not the ice, but the surrounding ambient heat.
A "Real" Stirling Engine has a regenerator, which apparently can be very efficient at preventing heat loss to the sink (the ice).
Most people, I mean YouTube videos I've seen, make no effort to insulate the ice from the surrounding ambient heat to prevent it from melting. I'm wondering what would be the result if the LTD Stirling (Preferably with a regenerator) were placed on top of a dewar type thermos full of ice. (As illustrated in the above experiment).
Ideally the engine should be running some kind of generator so as to be converting the ambient heat energy into some other form of energy, - electricity or mechanical output ("work").
Could that energy output then be used to actively remove heat from the ice as necessary so as to keep it cold and prevent it from melting and so allow the engine to keep running on the supplied ambient heat, which is really indirect solar energy.