The building engineer was skeptical, Scott Milne recalled.

Replace 4,500 fluorescent lights with 2,250 brighter, more efficient LED bulbs that would pay for themselves after one year?

But Milne, president of National Energy Technologies in Southampton, Bucks County, said he was able to persuade the Sheraton Philadelphia Downtown Hotel, on North 17th Street, to go for it.

Last week, the hotel got a $95,000 rebate check from Peco, just about equal to the cost of new LED bulbs sold by Milne's company.

An additional $110,000 in savings will come after a year's worth of lower energy bills, almost exactly offsetting the installation costs for the bulbs, he said.

"We floated the project until the rebate came through," said Milne, whose company has six salespeople. "They put some skin in the game, and I put some skin in the game, and we pulled it off."

The rebate came through Peco's Smart Ideas program to encourage energy efficiency, spokesman Ben Armstrong said.

The program has saved customers more than $460 million since the beginning of 2009 through a combination of rebates and lower energy bills, Armstrong said.

National Energy Technologies provides the know-how in applying for rebates and makes its money by selling the bulbs from a variety of manufacturers, Milne said. The company also sells smart thermostats, window-tinting technology, and other energy-efficient products.

At the Sheraton, union installers replaced pairs of 32-watt or 40-watt fluorescent bulbs with single LED bulbs that consume just 15 watts, Milne said.

He predicted that the hotel will save more than 1.1 million kilowatt-hours of energy each year, depending on demand and rate prices.

The new bulbs were installed in the hotel garage, kitchens, stairwells, loading dock, "back of the house" areas, and maintenance workshops, he said.