Further development of temperature system... Geothermal Energy!
Since we are getting more non-conventional energy sources (Wind turbines) and a temperature system I think it is a great opportunity to combine both and add Geothermal Energy into the game with the "Major Overhaul of Survival" update. It would be a very good alternative to both solar and wind power. (Correct me if I'am wrong) Since you can't find uranium on Earth-like planet anymore, geothermal energy would make a great addition to the game, allowing players to power their underground bunkers without relying on uranium.
I think it could work on two parts:
1. Main part being the generator that would work on steam turbine. I think that a block that is 1x1x2 or 2x2x4 would be ideal. There is not a lot I can talk about here since balancing it is up to Keen.
2. A block similar to conveyor, 1x1x1 size but instead of 1 large tube it would be made of 2 straight pipes that go verticaly (You can't rotate them horizontaly) and an additional 2 variants of this block: One that would connect both pipes at the bottom for the whole installation to work. 2nd a version of the vertical block that is airtight so you don't have any ugly holes in your base.
The generator block would have a slot at the bottom (Similar slot to the module slot, that doesn't allow conveyor attachment) to allow pipe connection. To make it simple: the longer and deeper the pipes are, the more power you can generate untill you hit the maximum output of the generator.
All components needed to make it happen are already in the game and the new temperature system already works so the closer to the planet core you are the hotter it is. The only thing that is left is to make it only work on static grids in natural gravity fields. (Allow building of these blocks on large grids for decoration purposes)
Please tell me what you think about this idea, if it fits SE or not really. I think if we could get Concrete (Already suggested by few people) and geothermal energy in this update the would be a godsend! It would make the survival update more interesting as most of engineers tend to start with a static base when landing on planets and some of them are concealed underground.