I want to suggest that the solar panel recipe could use silicon and not coal dust. How about adding a recipe to the blast furnace to melt silicon dust into ingots or even plates. That would make more sense than trying to use a hammer.
Next is why would you use a generator to make a solar panel? you could use a machine block instead, As far as I know solar panels dont store power, so why worry about re-batterys. It would like pulling out the battery out of your laptop just to store your gum in there.
For an achievment, "Star power" or something equally like minecraft. diamond picks and such