Oxygen and hydrogen storage. Oxygen’s used in the blast furnace, and to produce sodium persulfate for ore processing. Hydrogen mostly gets used in de-sulfinating petroleum, which yields H2S as a byproduct and then sulfuric acid.
Solar boilers on the roof, with water collection tanks. The solar boilers are largely outclassed by the steam boiler - they produce 72 watts at peak, vs. 400 for the main boiler. The nitro-diesel generators power stuff that draws over 1000 watts at peak.
Really obsolete High Pressure Coal Boilers. Altogether they produced about 120 watts. They have to be hand stoked, so I don’t use them anymore.
The workshop where I build stuff. The colorful tables are project tables provided by Forestry - they act like crafting tables, but they have a small inventory, and remember the last 9 things you crafted.