More alternative energy options exist. Check our first-ever report on a wind turbine designed for residential use, to see how the technology stacks up against other forms of residential alternative energy, including solar and heat-pump water heaters. Geothermal systems, which use the relatively constant temperature of the earth to heat and cool homes, are an emerging alternative to fossil-fuel-powered systems.
A home energy audit can identify low-tech, high-yield energy retrofits. Your utility or state energy office might offer low-cost audits. But be sure they're using pros certified by the Building Performance Institute or the Residential Energy Services Network. They undergo classroom and hands-on field training in whole-house energy audits, and continuing-education requirements ensure that they keep up with the latest practices and technologies. Expect to pay between $300 and $800 for a complete audit. The DOE's website, at www.energysavers.gov, has advice for conducting your own audit. If your furnace or boiler needs upgrading, you'll earn a 10 percent tax credit if you buy one with an Annual Fuel Utilization Efficiency of 95 percent or greater. It must be installed by Dec. 31, 2011. A 30 percent tax credit is available through 2016 on alternative technologies, including wind, solar, and geothermal.
Using a space heater to lower winter heating bills will work only if you turn down the heat in the rest of the house. And open floor plans might need multiple heaters. Also think hard about having your ducts cleaned unless they contain visible mold or vermin, or debris is coming out of supply registers. Shoddy work by an untrained cleaner can damage your ducts, and there's little proof that cleaning ducts prevents health problems or improves heating- or cooling-system efficiency, the Environmental Protection Agency says.
A.O. Smith PHPT-80, $2,250 (installed). This hybrid electric water heater, with a heat pump that extracts heat from the air and uses it to help heat water, delivered 59 percent energy savings compared with a standard electric model.