Sun power: solar thermal hot water systems save energy and money.

Not only does Bob Aresty of the Solar Energy Industries Association talk the energy-saving talk, he walks the walk. Aresty's beach home has a passive solar thermal hot water heating system because he says such systems are cheaper to operate and more efficient than traditional electric or gas products.

Other solar thermal proponents are seeing the light, so to speak, including California Governor Arnold Schwarzenegger, who recently joined with energy experts and the governors of New York, Texas, and Florida to encourage Congress to pass energy tax credits for such products. According to these forward thinkers, solar thermal systems, which use sunlight to heat water in rooftop collectors that is then stored in tanks for use throughout the home, are the wave of the future because they save both energy and money.

ON THE REBOUND

Available for decades, solar thermal hot water systems are beginning to bounce back after taking a nosedive in the '80s.

"The problems began in the end of 1985 when the Reagan administration and Congress eliminated the 40 percent tax credit available to most Americans that encouraged the installation of solar water heating systems," recounts Bill Guiney of Solargenix Energy, a manufacturer of solar energy products.

These days, the federal government is working to turn back the clock with programs that support solar thermal power. For example, the Million Solar Roof program operated by the DOE began promoting in 1997 the installation of solar energy systems--including photovoltaic and solar thermal--in commercial, municipal, and residential buildings.

As of December 2003, there were more than 300,000 solar energy systems of all types in place, says Katy Ansardi, outreach coordinator for the North Carolina Solar Center, which is part of North Carolina State University's College of Engineering. Many solar thermal systems are in public, municipal, or government buildings because these spaces guzzle large quantities of water.

But awareness of the Million Solar Roof program and other renewable energy efforts by consumers and home builders is swelling. The North Carolina center manages the Database of State Incentives for Renewable Energy Web site that the DOE funds. State and federal rebates (including solar thermal incentives) are piquing both builders' and homeowners' interest, translating into 20,000 hits a month for the Web site, Ansardi says.