I had a lot of transit tubes in my colonies.
With 110 dupes using the transit tube system it became a huge energy consumer, especially with dupes using stations to jump just a few tiles far. From my experience I would only use transit tubes to create point to point connections at the 4 corners of a map - For very long distances.
I decided to destroy all transit tubes, with the released 100 tons of plastic I am changing my internal colony to now consist of plastic ladders.
I can now also get rid of most heat generating transformers inside my colony, I am implementing a 50kW power line entry/exit at the lowest and coldest point of my big steam room - Insulated in a room filled with oil. Most stuff which produces heat will be move to the inside of the steam room.
The colony nearly went extinct again, so I am using the opportunity to change the entire colony to the better. This time I am building a new farm from scratch
Filling the exit/entry 50kW line connection module with oil