In good weather, you can use natural light to your advantage by opening windows and drawing back curtains, rather than lighting your house 24/7 with lamps and ceiling lights. In hot weather, use heavy curtains or shades to block out the heat and prevent your AC from working overtime.
For those times you do need artificial light, consider using compact fluorescent light (CFL) bulbs. CFLs use 50 to 80 percent less energy than incandescent bulbs and can last up to 10 times longer. Just as with rechargeable batteries, CFLs cost more upfront, but a single bulb could save you $40 to $50 in its lifetime.
