You might be interested to know that the mob who want to do battery replacement are also in the market to to supply peak power back to power companies using their batteries that they keep ready for customers to use.
Hadn't thought of that :) An interesting first step. It would be an improvement on my model.
With regard the voltage output of domestic generation systems, the solid state converters SHOULD be able to give an acceptably good o/put considering our mains varies quite a bit already. The generators monitor and control frequency, not voltage.
When the sun is shining and PV system is giving o/put, is your house isolated from the mains? That could be a problem.
