If you place a coal power plant on a deposit it will have a productivity bonus and the deposit will run out over time, reducing the bonus.

(v1.6.9 build 4890)
But if the coal power plant is placed on a field with no deposit at all it will work just fine (without the bonus of course) and is going to produce coal out of nothing, forever. Even on a custom planet with absolutely zero fossil fuels ...

This is also the case in "hard" mode.

I see global warming is the short term driving force in the gameplay, but at its core the game should be about unlimited growth vs.limited ressources. And it misses this one completely.
It's a big missed opportunity for conflict, too.

You're basically right. this is poorly handelt and should be a core topic of the game we're looking into it. Maybe we'll find a way to make coal tradable or stuff like that... at least we should come out with a negative production indication of a certain percentage to show, that underproductive from a certain point on.

Oh, thanks for the reply!

Letting players buy coal, gas and so on sounds like a good solution. It will allow to finish e.g. a mission in time before money runs out and without deviating from the mission goal to transform the energy sector.

It would be interesting to have the prices for imported energy linked to how much is imported, cause the galactic prices for energy would heavily impact the profts of the importing colony.

All in all players would be required to think more ahead. Making fossils limited seems like a ticking clock, but with galactic imports (even from your own colonized planets, where do all these rockets go?) there's a measure to prolong the current energy mix and even find a balance without running into debt.

Maybe you could also tie the prices and amount of underproductivity to the difficulty level, with 'hard' or 'very hard' having zero rest productivity of fossil power stations.