Hello
I dig up the subject which is always interesting
thank you Gregory for this reminder of ownership
On the cogeneration side, and more generally on the energy side, things have changed.
Photovoltaics have become really affordable, and the routing of the surplus, to a hot water tank for example
Cogeneration from fuel oil or diesel or any other fossil fuel seems to me quite useless, especially given the state of the planet (see the conferences of arthur keller)
The idea that I had before all this was this
We start with a car diesel engine for its price and its availability and availability of parts over time
we use one, or two cylinders to make it run with renewable, free, (vegetable oil)
one or two cylinders are used to compress air, for storage, then use with a compressed air motor (basic tool or not)
The heat from the engine is used to heat with the air, and the water from the cooling system
management is done with an Arduino or similar
the inconvenients :
it takes constant maintenance, Madam will not know and will not want to make it work, teenagers either!
The noise, you have to be in the countryside
find free oil
lots of debugging time
Advantages :
Almost zero implementation cost because almost everything can be recovered, especially in the countryside (cars for engines and alternators, storage tanks for compressed air, wiring, ...)
should be considered as a back-up, in addition to other systems
you can use the excess power or electricity to lift a weight or water but you need slope and space ...
This should be planned either as a hobby DIY, or as a production tool in a permaculture farm, but viable, review the conferences of arthur Keller and on the subject.
Conference of April 12, 2019 "Permaculture in the face of collapse" led by Arthur KELLER, Vincent MIGNEROT and Joris DANTHON. The event was organized in Nantes by the Permaculture 44 and Adrastia associations.
There you go, it's a bit confusing, but it gives an idea.
Olivier