Not since Jimmy Carter was president have so many Americans paid attention to the energy they consume. The price of gasoline is up 86 percent since the start of 2004, and natural gas is up 54 percent. Cities around the country had electricity blackouts last summer. The issue of global warming has hit the local multiplex. But there is some good news: Energy conservation can be one of those win-win situations. Here are some smart, easy ways to cut back on the amount of energy you use, saving you money while helping to save the environment.

Our estimates of annual savings in dollars and reduced carbon-dioxide emissions for changing your energy-consumption habits are national averages. Your returns might be higher or lower.

Do you make a daily urban commute or rarely drive? Own an older SUV or a late-model compact? Do you live in a well-insulated but huge home or a drafty old apartment? In Vermont or Arizona? Start with our figures as a general guide, then adjust for your own circumstances.


Heating and cooling

For most people, the biggest home energy usage is some combination of the furnace and the air conditioner. One of the easiest ways to cut energy costs is to have your home's ducts sealed and insulated, a procedure that should net you an annual savings of up to 40 percent on your heating and cooling costs.

Average annual savings: $310 and 3,268 pounds of carbon-dioxide emissions.

If it's time to replace your central air conditioning, Uncle Sam will help pay for it if you choose an energy-efficient model. Efficiency is determined by the seasonal energy efficiency ratio (SEER) of the unit. The higher the SEER, the more efficient the unit. This year, the federal minimum-efficiency level rose from SEER 10 to SEER 13 (an increase of roughly 30 percent). If you choose a model with a SEER of 14.5 or higher, you can claim a federal income-tax credit of up to $300 until the end of 2007 (and another $150 if you buy a high-efficiency furnace). Make sure that your contractor does the sizing calculations so you don't install a unit that's too big. It will cost more and require larger ducts to handle its higher airflow. The unit also may fail to provide the expected comfort.

Average annual savings: $70 and 1,001 pounds of carbon-dioxide emissions.


Hot-water heater

If your hot-water heater is less than 10 years old, you don't need to buy an insulated blanket for it--the newer units have enough insulation to make the extra layer unnecessary. Do, however, set the thermostat at about 120° F, or between low and medium. You won't feel the difference in the shower, and your plates in the dishwasher will still be sterilized.

Average annual savings: $24 and 187 pounds of carbon-dioxide emissions.

The typical gas or electric storage-type water heater has an average life of 10 to 15 years. When it fails, frequently because of corrosion, it must be replaced. Because of new standards, new models are up to 10 percent more efficient than older water heaters. If your heater is 15 or more years old, replacing it is "not just a tremendous energy savings, but it can save you a lot of trouble," notes Jennifer Thorne Amann, a senior research associate with the American Council for an Energy-Efficient Economy. "They don't give you a lot of warning when they go, and then there's water everywhere."

Average annual savings: $30 and 230 pounds of carbon-dioxide emissions.


Vehicles

You don't have to switch from a pickup to a subcompact to save money at the gas pump (although that choice would save you a lot). But neither must you limit yourself to super-efficient models to enjoy significant savings. Choosing a vehicle that averages 16 mpg instead of one that gets 14 mpg will save you as much fuel each year as choosing a 51-mpg vehicle over one that gets 35 mpg, assuming you drive 15,000 miles a year.

Average annual savings: $401 and 2,546 pounds of carbon-dioxide emissions.

Whatever vehicle you drive, slow down a bit. In our tests of a family sedan and a large sport-utility vehicle, fuel consumption was reduced by almost 15 percent by going 65 mph vs. 75 on the highway.

Average annual savings: $123 and 779 pounds of carbon-dioxide emissions.


Lawn mower

Your lawn mower doesn't use a lot of gasoline. Cut the grass for an hour a week on a lawn tractor and you'll burn about 10 gallons of gas a year. But if you use an inexpensive manual reel mower, you'll be able to quit those trips to the gas station to fill up the gallon can. You'll also keep the air cleaner. In addition to producing carbon-dioxide emissions, lawn-mower engines are relatively dirty when it comes to creating NOx, one of the key ingredients in smog. One hour on an average riding mower emits roughly the same amount of NOx as driving a very clean new car for 75,000 miles.

Average annual savings: $23 and 148 pounds of carbon-dioxide emissions.

For more information on how energy conservation can save you money, go to our Web site at www.GreenerChoices.org.