1. Tier 2 Steam Engines and Solar Panels - simple enough. Space is at a premium, especially in mid-late game where digging up and moving your entire power supply just won't do. A second level of power production would be nice, say a steam engine that produces 100% energy and consumes 50% more heat than default or solar panels that produce 20% more energy.
2. Tier 2 Accumulators - Having a second level of accumulators that can hold more juice would be nice. They're already very space intensive, so being able to cram 50% more power into the same space would be oh-so-helpful.
3. Chargable Power Armor - It would be nice to have an upgrade for power armor that allowed a play to stand near a roboport to charge its batteries without installing actual power production. Solar panels are just too slow and the fusion reactor is way to big.
4. Tier 2 Armor Solar Panels - Lets face it, the standard panels suck. 1kw per slot is nothing, and yet it is the only armor module that occupies a 1x1 space. A tier 2 panel that costs 10 tier 1's that produces 5kw would be a godsend for those who want to squeeze every last square out of their armor.
5. Discharge Defense Remote - Let us put it in the weapon's bar so we can use it like a weapon.
Well, that's all I got. I know many of these things can be fixed by mods, but my favorite flavor is vanilla

Any feedback would be greatly appreciated.