This light bulb is suspended in a magical crystal which causes it to light up without so much as a battery! Well, actually, it is the photoluminescent "filament" that makes the magic happen, but the effect is basically the same... it is the effect of the mutagen filled bulbs that illuminate Shredder's lair.
But seriously, I like to think of it as a solar light that looks cool enough to keep on your nightstand. Actually, you might want to to keep a traditional solar light on my nightstand to charge this one for better energy recovery. That's what I would do.