It depends on what your power requirement is. For a 200C difference, you should be able to get around 500W to 600W with a properly built stirling engine.
Sounds nice for all the people running off-grid up here who get so little precious sunshine in the winter.
Can you provide more information on where I might be able to buy such a Sterling engine? Are there any companies actively making them?
Thats what we saw and why we started the project - just not enough solutions for real world requirements. The engine itself is somewhat simple, its the thermodynamics that are tricky - There are only a few moving parts, no spark plugs, no oil, no valves and works off of any kind of heat.
Unfortunately, there are not many companies building these engines commercially (at least at these power outputs). Most of the engines I have seen are built by hobbyists (either too tiny or crude :( ). That's changing in recent years with increased focus on solar power.
