Give petroleum generator energy thresholds (like the wheel)

[Coolthulhu]

Petroleum generator, with its 2kW and tons of waste, is very unwieldy and relatively hard to use well. It is just plain less efficient (in power to waste ratio) than natgas, which requires no duplicant work and is available in huge amounts.

While load following power plants IRL are usually gas turbines, not all natgas power plants are load following, while pretty much all petroleum ones are. Load following in the game could be as simple as making the generator turn itself off when "all batteries full" event is fired, then turn itself on when "batteries below x%" event is fired.

By giving the petroleum generator ability to shut itself off when it is not needed, then automatically start itself up again when it is, its high energy generation would not be wasted and it could serve as an emergency generator when everything fails for some reason. This would make it more useful for the midgame colonies which do not need giant generators and would need to feed the petroleum generator through a valve, don't have a full cooling system up yet, and have more important things to waste dupe time on than turning the wheel (but could still use extra power in an emergency).