Geothermal

Geothermal is a Tier-2 module, and an Unimplemented module. It was originally intended to provide a passive stream of power via underground geothermal vents. It has been since removed from the game, but it can still be brought back to the game via cheat engine.

It costs 2 stacks of copper to build when unlocked.

Trivia
It was removed from the game due to the fact that geothermal vents were buggy and the generator didn't work properly.

Placing something in a geothermal vent will make it larger, possibly meaning the Geothermal generator was supposed to be bigger when placed on it.