So; Evacuated Tube water heating and Solar.
Use the Solar power during the day and store Hot water in an insulated tank for the Stirling Engine use to make electricity once the sun sets.
(And for home use any time)
I NB that the Stirling Engine relies on the delta T between its hot and cold sides.
The water is losing temperature at night, but the air cooled cold side of the engine will be cooler too as temperatures drop, so there should be no slowdown in the rate of electrical (and mechanical) energy generation.
Also NB that when you cut the heat to a Stirling Engine and turn it with say an electric motor, it becomes a 'Cooling Engine'.
That means that during the day you can use solar to turn a motor, to turn the Stirling, to aircon your house.
Also nice is that biogas from food waste and/or poop can be stored and used untreated to heat the Stirling Engine on cloudy days or to suppliment power at night.
You get around 100L of Methane from 1kg of waste biomas. (food leftovers)
IIRC there's around another 50 liters of gas from 1kg of (antibiotic free) poop if one chooses to add that to your bio-digester.
Most importantly is that you do get maintenance free biodigesters!!
It's all very clever and interesting, which I like.
But with the exception of the biomass thing; the system does nothing one cant do with Solar and batteries.
A small battery bank will still be required to handle electric spikes and peak loads.
The question is then:
How does it compare in price to an equivalent large Solar and Battery bank..?
Or a good CCHP system??