The image of 24 inefficient electrical engines with a solar backend makes my teeth itch. It would seem the 'fire and forget' quarry is about to be upgraded to 3 bluetricity engines with sufficient wind gen, whatever that turns out to be.
Edit: and as much as I like that idea, I think I will still prefer the mobility of a redstone energy cell powered quarry, at least in SSP worlds.
This is why I think solar arrays should be removed from the pack, and the advanced solars to produce 2 eu/t, 4 eu/t, and 32 eu/t, respectively, while producing 0 eu/t at night (if they are to be kept in the pack).
The windmills aren't so OP because they break over time, and you'd need a couple to power a quarry.
For now, though, I have a lava pump in the nether pumping lava into a liquid transposer which fills lava cans and sends them to an enderchest, then to my system. Then the empty cans in the Overworld are piped to another enderchest to be transported to the nether and refilled.
One lava pump is enough to power my 6 geothermals and a couple of magmatic engines. I do have 5 electrical engines as backup, however.