Three-can "strange engine".

I found this last night.  There's this guy Robert Murray-Smith who does these tinkering videos, and in one set of them he shows off this design for a super-simple Stirling engine (or maybe thermoacoustic?) made from three food cans, a bit of balloon rubber, and some gravel.  This could be the simplest engine?

As a bonus he also shows a two-can micro-gasifier stove (a rocket stove that makes charcoal).

So with five cans and some magnets and wire you can make a simple wood-burning electric generator, or you can power it from a solar collector or a sand battery.

He makes one with methanol as the working fluid and runs it off the difference between some hot water and the air.

"1771 A Strange Steam Engine For Home Generation That Anyone Can Build"


"1772 The Secrets Of The Strange Engine - In Detail"


"1775 Running A Strange Engine From Hot Water"


"1779 The Strange Engine As A Generator"


"1703 Mini Gasifier Or Mini Rocket Stove With Mantle"


Should I spend ~$1000 on a solar system or just bang some cans together?

Buy the solar system.
Then build a full size RMH.

Oh I'm going to get some PV panels, no doubt, that was sort of a joke.

As far as I can tell the only difference between a rocket stove and a micro-gasifier stove is that in the latter the chamber that holds the wood is vertical and directly under the gas combustion chamber.  The pyrolysis fire burns down through the wood like a candle leaving behind charcoal (for biochar or whatever) instead of ash.