when using Power Plants it feels to me like cheating because it reduces the cost for electricity to 0.
So at this point I would feel much better if fuel is needed to generate the electricity.
Because a Power Plant costs money and occupies some space it should be cheaper to buy the fuel than to purchase electricity. At all there must be some attraction to do the research and build this slot so there should be a benefit for producing the electricity in-house.
An improvement of this suggestion could be to add new slots for fuel tank and fuel receiving. A new fuel pipeline with resticted placeability could make the layouting of a production line and it’s supply chain a bit more challenging.
Would be great to know how others thinks about this.