To reduce hot-water consumption (and energy needs), federal legislation mandated improved showerhead efficiency for models made after 1994. Replace older models with ones that spray no more than 2.5 gallons per minute.

Potential annual savings: $145, plus 370 pounds of emissions

Refrigerators use more electricity than any other appliance. Older ones are worse, so give top priority to replacing a pre-1993 fridge.

Potential annual savings: $70, plus 1,720 pounds of emissions

Single- and even some double-pane clear-glass windows can force heating and cooling systems to work overtime. Energy Star-qualified windows with insulating glazes, gas fills, and better framing materials deliver the best results.

Potential annual savings: $95 and 2,200 pounds of emissions

Energy Star dishwashers can be more efficient than hand washing. Run full loads, air dry, and skip the pre-rinsing (most newer models don't need it).

Potential annual savings: $25 and 110 pounds of emissions

Lower your water heater's thermostat to 120 degrees to restrict heat loss. The exception: dishwashers. Check if yours has a "booster heater" for sanitizing 140-degree rinsing.

Potential annual savings: $450 and 215 pounds of emissions

Lower the thermostat by just two degrees this winter to conserve energy without sacrificing comfort. Turn it down 10 degrees at night and when you're not home -- or install a programmable thermostat for automatic adjustments.

Potential annual savings: $100 and 500 pounds of emissions

About 90 percent of the energy used for a load of laundry goes to heating the water. Some stains demand hot water, as do bed linens (to kill dust mites). Wash all other loads in cold.

Potential annual savings: $300 and 330 pounds of emissions

Compact fluorescent lightbulbs consume a quarter of the electricity required by comparable incandescent bulbs and last up to 12 times longer. Maximize savings by changing at least five frequently used bulbs.

Potential annual savings: $60 and 770 pounds of emissions

Many household appliances continue to suck electricity even when switched off; nationally, this creates the annual emissions equivalent of 17 power plants. Minimize leaks by unplugging idle electronics.

Potential annual savings: $200 and 480 pounds of emissions