For several years, the Long Island Power Authority (LIPA) has arguably offered the best solar PV rebate program in New York, if not the entire country. The per-watt rebate — available to homeowners, businesses, schools, and public and non-profit entities — has not been limited by an absolute dollar-amount or percentage cap. Most solar rebate programs, by contrast, place an upward limit on the total incentive on offer — e.g., $2.50/watt, up to $12,500, or, $1.75/watt up to 25% of total system costs. As reported by Newsday, LIPA is moving in that direction — and is also set to reduce the per-watt sum available.

Effective immediately, the LIPA solar rebate is capped at 50 percent of total system costs. For example, a homeowner who installs a 5-kW solar PV system costing $30,000 will qualify for a rebate of $15,000 — not the $17,500 ($3.50/watt * 5,000 watts = $17,500) that was available previously.

The other shoe is set to drop on January 1, when the per-watt rebate is reduced to $2.75 from $3.50.

LIPA cited lower solar-panel prices and installation costs, and an increase in the federal tax credit for solar energy systems instituted in January.

Solar installers said the move was expected. “It was just a matter of when, not if,” said Sail Van Nostrand, owner of Energy By Choice in Greenlawn and vice chairman of the Long Island Solar Energy Industries Association. He predicted the January cut would slow sales somewhat, but said it would help spread LIPA’s $18 million solar budget to more customers.

It’s the seventh time LIPA has trimmed rebates since starting the program 10 years ago. Since then, it has doled out $52 million in rebates for more than 2,100 solar systems on Long Island.

Gordian Raacke, a solar proponent at Renewable Energy Long Island, noted a separate New York State-sponsored solar rebate program also was recently reduced. He said the new 50 percent cap would likely have a small impact in the market, but the $2.75 reduction would have a larger one.