The gathering in a pasture near Fayetteville had all the makings of a good, old-fashioned tent revival.

A fervent sermon, an eager audience and summer heat. Except the sun inspired this gathering.

Alexander Acosta/aacosta@ajc.com (ENLARGE)

George Andrews of Solar Source of Georgia speaks Friday about benefits of using solar energy at the residence of Jan Grogan.

Alexander Acosta/aacosta@ajc.com (ENLARGE)

Jan Grogan looks Friday toward the sun. Behind her is a barn where solar panels are installed on the roof.

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"It's going to power all your needs," said George Andrews, gesturing toward a nearby barn with a pitched roof covered in solar panels he installed. "It's all there, and we can make it happen."

Solar energy — transforming the sun's power into electricity — may never replace coal, natural gas and nuclear energy. But there are enough true believers in Georgia to offer hope that the sun's power could supplement those sources.

A new state law that took effect July 1 gives Georgia homeowners an extra incentive to consider the solar option. The state now offers an income tax credit up to $10,500 for residential solar energy installations; up to $2,500 for solar water heaters; and up to $2,000 for a geothermal heat pump. Federal incentives, set to expire this year, offer up to $2,000 for solar-electric systems. Commercial properties are eligible for even more.

One drawback for renewable energy advocates is that Georgia capped the total credits at $2.5 million per year through 2012. Jason Rooks, a clean energy lobbyist who helped write the bill, said he hopes to remove the cap or raise it next year.

Friday's gathering celebrated what is believed to be the largest residential solar installation in Georgia. The 54 panels on Jan Grogan's roof will produce 1,000 kilowatt hours per month.

For most homes, that would be enough. But Grogan's 4,000-square-foot, 1987 ranch-style house uses more electricity than the average, even in the air-conditioned Sun Belt. Grogan is running two well pumps, two water heaters, two air conditioners and a security system.

There are no solid numbers on how many houses in Georgia are powered with solar energy, but it could be as few as 30. That's expected to grow as energy prices continue to rise.

Grogan, who sells plastics for food and medical applications for a Japanese-owned company, said she invested more than $100,000 in her solar system for one reason: independence. "The only way that we Americans are going to be able to get a handle on sources of power is if we invest in things like I have — solar or wind power," she said.

Grogan may never live to see the payback on her investment. But Andrews, whose Barnesville business is called Solar Source of Georgia, said that's not a good measure.

A solar system is "like owning your own power plant that produces 40 to 50 years of electricity and possibly more," he said. "Once you put it up there, the fuel is free forever. ... And this is clean energy. There's no shipping, there's no mining, there's no nuclear waste."

In Grogan's case, she'll also get a 4- to 5-cent rebate from her utility, Coweta-Fayette EMC, for every kilowatt that she produces and doesn't use. Any excess flows to the grid.

Georgia Power buys solar-produced electricity at 17.4 cents per kilowatt.

Michael Whiteside, president and CEO of Coweta-Fayette EMC, is also president of Green Power EMC, a partnership of 37 member-owned electric cooperatives in Georgia that are developing renewable energy sources, including a chicken litter-to-energy plant. "All of us are currently trying to find a solution to our future energy needs," Whiteside said. "We need coal, nuclear, natural gas, renewables — it's going to take all of that coming together so when you walk in your home and turn on a switch, everything comes on."