Install energy efficient lighting. This LED lamp from Lighting Science can be used to replace a 75-watt incandescent bulb but it uses only 8 watts. LED lights are still much more expensive which is why they are mostly used for commercial applications at this point. Compact fluorescent bulbs, meanwhile, are far cheaper than they used to be and the quality is getting better. They contain small amounts of mercury so they should be disposed of with hazardous waste.