So I JUST installed the mod and in this K2SE playthrough, my base was capable of outputting 9Gw of power. After I installed it, my base's power limit jumped to 15+Gw and the Flat Solar Panels 2 (red ones that give 800kw by default) were now outputting 2.1Mw each, without a single research into productivity yet. What's worse, is that researching any more does not actually increase the solar panel's actual capability at all. Could this be some conflict with another mod?

It's really weird. I might have to take a look at the save before/after to better understand this

Yes i have the same issue, i am using - Advanced Solar and Accumulator. Also when i research the actual technology no bonus is applied either to the solar panels or the accumulators. So far at least, i have researched the first two techs.
Edit: The solar panels themselves and the accumulators do state they are affected by this mod.
Edit 2: After 3 or 4 researches (not sure) they started to take effect normally.

Fixed with the latest release v0.3.5