Solar energy isn't the only renewable technology to get a bump from federal tax credits.
Wind, geothermal and solar hot-water systems also are eligible for new, uncapped federal tax credits. That's in addition to incentives from LIPA and National Grid.
Gordian Raacke, executive director of Renewable Energy Long Island, a LIPA consultant, said all those types of energy pale in popularity to solar energy systems on Long Island, though he said they are likely to increase. Solar hot water systems, which cost between $6,000 and $8,000, are extremely cost-efficient and have generous incentives, he said, offering a quicker payback time than solar energy.
Still, Raacke estimated perhaps only hundreds of systems of solar thermal and geothermal energy have been installed here. Wind turbines, he estimated, likely number "less than a dozen."