Burlington Electric has decided to continue purchasing power from Sheffield Wind’s 16 turbines for another five years despite skepticism from critics and a local resident over whether the facility is functioning properly.
For this contract BED will purchase 16 megawatts of its 40-megawatt production.
“Including wind power in our energy mix is good for Burlingtonians. With this agreement to continue purchasing Vermont wind energy, we’re supporting our work to both keep rates low and pursue our Net Zero Energy goal,” Burlington Mayor Miro Weinberger in a statement.
Darren Springer, general manager of Burlington Electric Department, says the contract extension is part of the company’s “ongoing strategy to source 100 percent of our power from renewable generation, with an emphasis on supporting local renewables in Vermont.”
“At the same time, we are very pleased that this agreement offers an even better price for our customers, and is helping BED enter our 11th consecutive year without a rate increase,” he said.
Washington Electric Cooperative, another utility that purchases Sheffield’s power, is on a 20-year contract until 2032. According to a 2018 report, WEC pays $572K per year for 4 megawatts for Sheffield’s power.
WEC manager Patty Richards told True North that the exact amount per kilowatt the company pays is confidential, but she said it’s a good deal for their members.
Not everyone thinks sourcing energy from Sheffield Wind is a smart move. The turbines were built using an old gearbox technology constructed by manufacturer Clipper Liberty — which as since experienced “financial turmoil”. Similar installations in upstate New York using these designs have a reputation for break downs and oil leaks.
Rob Pforzheimer, a Sutton resident who lives four miles from the Sheffield turbines, told True North on Tuesday that four of the 16 turbines appear to have stopped working for the last few weeks. He said at least one of them has been malfunctioning for much longer.
“That doesn’t matter for Burlington Electric — they just get the electrons off the grid, they don’t get a direct line from Sheffield Wind,” he said.
Pforzheimer added that the turbines have been malfunctioning on and off for most of the wind farm’s 8-year lifespan.
Today Pforzheimer maintains that the Clipper turbines have a poor performance record at Sheffield and elsewhere.
“The ones that they had in Buffalo, New York, that they installed there, they were the Clipper turbines that they were boasting about. They were all broken and had to be replaced,” he told True North. “And they put some of them in Cohocton, New York, and they got taken out of there.”
Annette Smith, executive director of Vermonters for a Clean Environment, told True North she visited the Cohocton project shortly after it went online, and what she saw wasn’t good. In 2010, she wrote that 15 out of 50 turbines were not working on a visit she made a year earlier.
Smith told True North that developers of Sheffield Wind “never should have been allowed to put up those models” of turbines.
According to a 2014 report at MachineDesign.com, the gearbox design used in Sheffield and Cohocton are prone to failure.
“Gearboxes in wind turbines, more than those in any other application, tend to fail prematurely,” it states. “In fact, at some wind projects, up to half of all gearboxes fail within a few years.”
Richards said if it’s true that some of the Sheffield turbines are not working, “I wouldn’t get too upset about it.” She added that sometimes the turbines will get maintenance and that can take some time.
She further added that part of the Washington Electric Cooperative contract with Sheffield Wind includes that if the power production from Sheffield drops below a certain level, that power must be supplemented from another wind facility to fill the gap.
The current owner of the Sheffield installation is Terraform Power. Requests for comment from the company were not returned in time for publication.