If you really want to be energy efficient, you could put a LED bulb in it. The good news is they use far less power than even compact fluorescent bulbs, and last far longer. The bad news is they cost a fortune, a quick search showed $40 for a 60-watt equivalent bulb (that actually uses 7 watts). They claim a lifespan of > 50,000 hours, I'm not sure if that's true, but if it is that's about 10 times better than a compact fluorescent and 50 times better than an incandescent bulb.