Fossil fuel generators, can be hidden in trees or underground and vented.

Solar panels are easy to spot from a drone, and fragile, so it's easy to damage them.

My friends in Ukraine charge their ecoflows with a generator, because if you put a solar panel outside your drone team bunker, you invite incoming artillery.

Of course, I was talking about civilian use, not implying drone teams might spin up a nuclear reactor for a bit of warmth. Solar panels and heat pumps won't make a block of flats more of a target.