For example, in summer you dont need the heat, but you do still need electricity. And in winter you need a lot of heat, but not always the full generator capacity.

It sounds like you need solar panels with some power storage enough to charge during day and provide power through the night for summer, and then the generator for winter, but use it not just for its heat but also electricity (portion of heating would be provided with IR emitters powered with electricity). That's from layman perspective - I have no idea what I'm talking about :o)