The path to lower cooling bills starts with your thermostat. By Andrea Browne Taylor, Online Editor July 28, 2016 Keeping cool can prove costly. The average electric bill tops $400 during the summer, according to government estimates, with air conditioning accounting for much of the expense.See Also: 6 Home Projects That Save Energy and Money The simplest way to lower your home’s cooling costs is to raise the temperature on your thermostat. Setting it at between 76 and 78 degrees can reduce your monthly bill by as much as 30%. Want to save up to 10% more? Use a programmable thermostat to raise and lower the temperature automatically depending on when you’re home. You can pick one up for as little as $35. (“Smart” thermostats run about $200.) Finally, if your air conditioner is on its last leg, consider replacing it with an energy-efficient model. Not only will you save money in the long run, but you might also qualify for a $300 federal tax credit. A/Cs typically last about 15 years. (Go to EnergyStar.gov or IRS.gov for more information on the 2016 energy tax credit.) Discover more ways to save on your home cooling bills.