harry wrote:

If I bought a petrol generator,I would have to buy petrol forever more.

No you wouldn't. It will burn alcohol, which can be made easily from
plant material, or synthesised hydrocarbons made by using carbon
dioxide, water and nuclear energy.

If desperate, you could split water using solar energy, and perform the
minor conversion to let the engine run on hydrogen.

--
Tciao for Now!

John.