Cogenerator to heat Swampscott High

SWAMPSCOTT – Engineers described it as a big diesel truck engine. But while such a description may not immediately call to mind energy efficiency, the new cogenerator at the High School will provide half of the building’s annual heat and be nearly three times as efficient as typical heating systems.”It is extremely efficient,” said Rob Davis, vice president of Systems Engineering at Groom Energy. “Compared with 30 percent conversion (of fuel to electricity) you get from ?the grid,’ this converts 80 percent of a fossil fuel to electricity.”The school buildings were responsible for 68 percent of the town’s total municipal energy cost of $966,653 in 2009, according to data from the Renewable Energy Committee. Of this percentage, the high school is the town’s highest energy user, responsible for $347,325 or 36 percent of the town’s total energy costs.The cogenerator – which had its first test on Wednesday morning – will significantly reduce the school’s energy use. In a typical heating system, only approximately 30 percent of the energy in the fossil fuel actually is converted to electricity, Davis said, while the remainder is lost, primarily, through the heat produced by that conversion. The new cogenerator converts 80 percent of the energy of fossil fuels into electricity by capturing the heat produced and using it to heat the building, Davis said.School Facilities Director Garrett Baker said that the cogenerator will supplement the two boilers that currently heat the building, reducing costs by more efficiently providing approximately half of the heating needs of the school during cold weather.Although the cogenerator is relatively simple in concept, Davis said that only about 1,200 of them are used in a commercial or municipal setting worldwide.”The key to success is having a hot-water demand,” he said, saying that community centers with heated pools are the primary application of cogenerators of similar size.The high school’s natural-gas powered hot water heating system also meets the demand.Although the cogenerator is located outside, the extra heat it produces will be pumped into the building through underground insulated pipes, Davis said. The American-made unit will be able to operate in all weather and is contained in a hospital-grade acoustical enclosure that is “extremely quiet.” He said he couldn’t say how much the cogenerator project cost, but said it was paid for through a shared-savings agreement – meaning that the town repays the installation and construction costs by devoting a portion of the savings the project generates. Groom Energy is responsible for the maintenance for the first year, and then the contract will be renegotiated on a yearly basis, Davis added.Baker said that the cogenerator will supplement the two boilers that currently heat the building, reducing costs by more efficiently providing heating needs in addition to furthering the town’s energy efficiency goals.”Swampscott High School’s going green all through and through,” he said.