It is possible that this already exists, but I was thinking that it would be fun to have an EM weapon dedicated to destroying power sources.
I imagine it would appear in Zion as one of the various experimental items that the Zionites sometimes give you.
It would be something like:
2 weapon slots
6 shots
5-7 damage each
very narrow spectrum (70% chance to cause explosions in power sources)
There are definitely some weapons you can already to this with, yes. In fact, some early-game weapons are quite good at it, for example using multiple EM Shotguns will have that effect quite frequently, thus it's not too good an idea to use doorway bottleneck strategies with this kind of armament!
There could be additional unique weapons with this ability, though like other uniques they'd have to be rare/non-guaranteed (because the effects are devastating :P), and those are situationally added as available spaces open up in the world.