1. Forgo using your central heating system and opt for space heaters (this is especially effective if you have a larger house and are really only in a few rooms during the day anyway).
2. Use ceiling fans instead of the air conditioner.
3. Use cold water to wash your laundry.
4. Use a clothesline.
5. Use compact fluorescents in lieu of regular light bulbs. This is a quick fix and the payback is there.
6. Hibernate your computer when it’s not in use.
7. Replace your AC filters when required (or use a permanent filter and simply wash it monthly).
8. Close the AC vents in rooms you don’t use.
9. If you have an old AC unit (10+ years old), replace it! The newer models use up to 50% less electricity.
10. Use a programmable thermostat for a central air unit and turn the air off while you’re at work.
11. This main seem simple, but make sure your fans are all spinning the right way :) You want to be pushing the air DOWN.
12. Knock the thermostat up a few degrees and see if you notice a difference. If you don’t, you just saved yourself 2-3 percent.
13. I love plants and gardening, so I’m also down with planting shade trees strategically (this can knock temperatures down by 20 degrees in a now-shaded room!).
14. Insulate your attic. Poor insulation may mean you’re losing 30-40% of the cool air in your house.
15. Make sure your ducts aren’t leaking anywhere.
16. Keep an eye on windows and doors to ensure they’re sealed properly.
17. Block sunlight with window coverings (drapes, blinds, shutters, etc.).
18. Install reflective film on windows that take a lot of sun. Payback on this is three to five years (though that may vary based on your own energy costs in your area). It doesn’t block the light — just the heat. Very cool.
19. Use rugs on bare floors to keep a room warmer.
20. Throw on an extra layer and lower your thermostat during colder seasons.
21. Use a special tank blanket to wrap your water heater’s tank (if you don’t use tankless). It’s not a huge savings though — about $20/year. (From Anthony, a commenter below: “There’s a huge, huge, ‘it depends’ here. Newer water heaters (we replaced ours in 2007) are much more efficient and don’t need this. More importantly, check your warranty – many say that the warranty will be voided if you use one of these blankets.” — Thanks for the caveat Anthony!)
22. Fix any leaky faucets.
23. If you’re shopping for a new dryer, get one with a moisture sensor. You’ll never run it longer than you need to!
24. Consider a front-loading washer. They use less water and they leave less water in your clothes (which means less work for your dryer).
25. Clean your lint filter after each load.
26. When the dryer’s running in the summer, close the door (keep the heat out) and in the winter, open the door (let the heat in).
27. Use motion sensors for outside lighting (payback’s usually 3-5 months).
28. Use motion sensing lights for the interior as well!
29. Increase the temperature of your fridge/freezer to the highest recommendation. You’ll save 5-10% of electricity that way and won’t notice a difference.
These tips won’t make you rich, but I find it very fulfilling to not be wasteful. Your own mileage may vary.