Since most suggestion threads are as ancient as the beta days of MC, I decided to make this freshly pinned thread for new suggestions.
I'll start:
Hotspring Water
- Ability to use hotspring water in the steam boiler (with calcification rates between water and distilled water).
- Less heating required to boil hotspring water to steam, since it's warmer than (distilled) water.
Oxygen
- Instead of metal uranium and plutonium fuel pellets, you have to oxidize them (in the fluid canning machine). This would make sense, since MOX stands for Mixed Oxide fuel.
- Usage of oxygen in blast furnaces: the higher oxygen content could help to speed up the production of steel.
Hydrogen
- Possibly as an alternative form of energy storage. Of course it is not 100% efficient unlike storing it in a batbox/CESU/MFE/MFSU, but it can be used in a fuel cell to generate electricity or burned in a (semifluid) generator for heat.
Pahoehoe Lava
- Convert it into a block resource (Basalt/Obsidian) or infuse it into Lava using magma (from the addon IC2Magma) in a fluid canning machine.
Steam Turbine (item)
- Rename the Steam Turbine (item) to Turbine rotor, as it seems illogical to put a Steam Turbine (item) in a Steam Turbine (block). This was suggested by Su5eD, but due to a small mishap with threads merging, I write it down here instead.
Steam Repressurizer
- Add a heat texture to the steam repressurizer block to make it clear that this block requires heat to work. (Su5eD).
Metal Armors/Tools Recycling
- Recycle/salvage basic armor and tools (non-electric, vanilla-style) into their base components: i.e. melt golden gear into gold ingots/nuggets. Non-metal materials would have to be cut (leather) or pulverized (diamonds). What use do you have for these loot items anyway when you have nanosuit/quantum?
Condenser
- Allow the usage of higher tier vents to speed up the condensation rate. Sometimes 3 condensors on 1 steam turbine won't cut it.
- OR: allow the piping in of water or ice to cool down the steam like a surface condenser.