Like the concept and looking forward to maybe doing more with it now that you can shut off tiers (never had a need for that much power from a solar field the way I've been playing, but the first or second their could be good...and who knows, maybe I end up using the top tier after all.)
Something I have been looking for though and can't find is smaller panels and accumulators rather than higher power...instead of the 3x3 and 2x2 grid size, maybe a 2x2 (or even a 1x1) array and a 1x1 accumulator. Logically I could see these unlocking as higher tier full size panels are unlocked. (Tech gets smaller/more efficient to make more power from the normal size meaning you can also make the same power from a smaller panel.) I've been playing with some ideas unsuccessfully (not much of a graphic designer or Lua programmer) and it seems like something that could fit with your mod so putting it out there as an idea.
Thanks