All our electrical power for the Antarctic base came from large diesel generators.
Cooling water for the diesels circulated through every building providing space heating.
When it was really cold, or if the electrical load was insufficient to provide enough heating, an electrical boiler in the water loop was switched on.
That both loaded up the diesels while also adding extra heat on top of that into the system.
That is pretty much the way everyone does it down there.
The Americans being the exception.
At Mc Murdo they run a small nuclear reactor.
If you want to focus on efficiency improvements first then you MAY consider as part of your outlay.. a thermal imaging camera of some sort! Cheaper ones are around $200 (except for some real low res stuff at ~$80