> I do not belive the 90 percent efficiency claimed by them. It cannot be
that good, due to the fact that there has to be major leakage (heat)
between the hot side and the cold side of the piston. Even if the 'block'
is plastic, there will still be a major heat loss. A burner (heat source)
can be 90 percent efficient, but any moving parts are going to shoot their
claimed efficiency specs down. If the efficiency was that good, they would
be all over the place, especially in off the grid and isolated locations.

Heat (as a byproduct) can be used to make cold air as well-so the unit
could heat in winter and cool in summer.

Flame suit on, fire away.

>>>>>>>>>>

I suspect that Whispergen NEVER claimed 90% efficiency for electrical
output.
What you MAY have seen is a claim for overall available energy output in any
form (electrical plus thermal) compared to max theoretical calorific value
in the fuel.

The Stirling is strictly limited by the laws of Physics as codified in
carnot's cycle to Efficiency max ever = (Tin-Tout)/Tin. To get to 90%
theoretical and with Tout = 300k (room temperature) you'd need Tin = 2700
degrees Celsius.  Nobody runs their Stirlings quite that hot :-). And even
then the ACUAL efficiency would be rather lower. Some utter loonies run at
around 1000 C and 3000 plus psi which places extreme demands on everything.
Working gas is usually Helium. Hydrogen is better but approximately
impossible to tame.


        RM

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