"Replace them with more-energy-efficient bulbs, which use less energy and produce about 75 percent less heat," Leonhart said.
The two kinds of energy-efficient bulbs Energy Star certifies are compact fluorescent (CFL) and light-emitting diode (LED), both of which have longer life spans than conventional incandescent bulbs.
Overcooling • Reset the thermostat. Cindy Olson, vice president of the green energy consulting firm Eco-Coach, said air conditioners are often left on when no one is home and set to temperatures lower than is necessary for comfort.
"It is something that is very personal," Olson said. "A lot of times, simply air movement is enough to be comfortable, even with just a ceiling fan."
Test how you and your family feel by adjusting the temperature up by one or two degrees at a time. Every degree of change, she said, can make a 2 percent difference on your utility bill. An air-conditioning system can account for 30 percent of an energy bill in the summer, according to power company data.
Old cooling • Updates in technology have made new central air systems, often with programmable thermostats, at least 15 percent more efficient than older models. If you aren't ready to replace your central air-conditioning unit altogether - the EPA suggests doing so if it is more than 10 years old regular maintenance will ensure your unit is running as efficiently as it can. A dirty air filter, for example, can damage equipment and cause early breakdown.
Unused appliances • Whether you're going on a summer vacation or not, unplug coffeemakers, toasters and hair dryers, or invest in power strips with energy-saving features.
"My computer charger was pulling a huge amount of energy," Olson said. "Unused appliances make up anywhere from 10 to 15 percent of your bill. It's not doing you any good to leave anything plugged in if you aren't using it."
Unsealed leaks • Both Leonhart and Olson also stressed weatherizing your home. If it's drafty in the winter, Olson said, it's still going to be drafty in the summer, letting cool air escape unless cracks or doors are sealed properly. And be sure to seal up heating and cooling ducts where air tends to leak, Leonhart said. Olson suggested having a professional inspect your home's heating and cooling system and make the repairs. Exposed ducts in crawl spaces, basements and attics are often fixed with duct sealants or metal tapes.
More cost-saving suggestions
Plant shade trees strategically around your home. Properly selected and planted shade trees can save up to $80 annually on the average electric bill.
Reduce the temperature of your water heater. Setting it too high (140 degrees or higher, according to Energy Star) can waste anywhere from $36 to $61 annually. In summer, a cooler shower is actually more pleasant.
If you raise your thermostat setting by only two degrees and use your ceiling fan, you can lower your cooling costs by up to 14 percent.
As much as 20 percent of the air moving through your home's duct system is lost through leaks, holes and poor connections. A professional contractor can identify leaks and fix them.
Source: EPA and the Potomac Electric Power Co. (Pepco)
To find all of the state, local, federal and utility incentives in one place, go to the U.S. Department of Energy's comprehensive list at dsireusa.org.
Energy Star's Home Yardstick is a tool that gives you a basic assessment of your home's energy use, compared with other homes in your neighborhood. Just plug in your Zip code, home's square footage and more to get your score. energystar.gov