One of the simplest ways to green your home, save energy and cut utility bills is to install programmable thermostats. After all, half of your energy bill goes toward heating and cooling your home [source: Archer]. Most energy companies suggest you set your thermostat to 68 degrees in cold weather and 78 degrees in warm weather. You can easily program your thermostat to stay at these temps automatically. Your HVAC system will only kick on when it reaches the designated temperatures in your house. You won't have to think about adjusting the thermostat again; it does it all for you. Plus, you can shave and additional 3 to 5 percent off of your energy bill for every degree you set your thermostat below 68 in the winter and above 78 in the summer [source: Archer].
You can also program your temps around your schedule to save even more on your energy bill. It's simple with a 5-1-1 thermostat, which allows you to set a separate program for weekdays, Saturday and Sunday. A 5-2 model lets you set a weekday program and a weekend program. If your schedule is particularly finicky, you can purchase a seven-day model that allows for a unique program each day of the week. You can purchase a seven-day programmable thermostat for as little as $40.