We can't break the laws of entropy but we sure can cheat them a little bit! I don't understand why a solar panel taking light from a light bulb to power the same lightbulb is a bad idea. Sure, it's not a perpetual energy device, but it's more efficient than without the solar cell. And we're all about efficiency nowadays, aren't we? I'm setting up a proof-of-concept solar capacitor charger right now and I'll make a blag post with photos later.