Summer is a good time to save energy, not only because of the expense, but because of summer's increased demand and risk of blackouts.

Saving energy doesn't have to be as painful as sunburn, nor does it have to cost much money or time. It has more to do with changing a few energy-wasting habits. And where costs are involved, such as having your cooling system checked annually by a professional, the expense can be offset by making your system more efficient and longer-lasting.

According to the Energy Department, heating and cooling use more energy and more energy dollars than any other system in your home. Typically, 44 percent of your utility bill is for heating and cooling. You can lower those costs by implementing some of the following tips:

* Install a programmable thermostat. It can be set to vary the temperature of your home according to your schedule.

For example, you can set it so your home is cooler in the morning before you leave and in the evening when you return. Set the temperature higher for the hours in between, when no one is home. Many thermostats have multiple-day programs so you can change the setting for weekends, when your schedule is different.

* Set your thermostat to 78 degrees when you're home and 85 degrees when you're out four hours or longer. Setting it lower will keep the cooling system running during the peak demand period and setting it much higher than 85 can cause the system to work too hard when it's asked to cool your home in the evening.

* Increase your lighting efficiency. Lighting can affect energy bills not only by the energy it consumes but by producing heat, which requires increased cooling. According to the Energy Department, replacing 25 percent of incandescent bulbs with fluorescent ones in high-use areas will save about 50 percent of your lighting energy costs.

Fluorescent lamps are much more efficient than incandescent bulbs and last six to 10 times longer. Although fluorescent bulbs are more expensive, they pay for themselves in energy savings. Look for the Energy Star label when buying these products. Motion detectors and dimmer switches also can help reduce utility bills, and both are inexpensive and easy to install.

But whether lighting is energy-efficient or not, turning it off will save energy, produce less heat and require less cooling -- and, of course, lower your bills. Also, consider shutting down home office equipment and heat-producing computer monitors when not in use.

* Use washing machines, dryers and dishwashers after 7 p.m. and you'll see your utility bill shrink. Also, when possible, wash clothing in cold water. If you're shopping for a new washing machine, consider a front-loader, which is typically more energy- and water-efficient.

* If you have a swimming pool or spa, operate the filter pump and automatic cleaner during off-peak hours -- before noon and after 6 p.m. Also consider investing in a solar cover that will passively warm the water and protect the pool or spa from debris, which means you might be able to reduce use of the filter pump and cleaner.