PEABODY — The fact that two new wind turbines atop Brodie Mountain in the Berkshires have recently reached commercial operation is a milestone that will provide a source of clean and predictable power for nearly 3,000 homes on the North Shore.
While the Berkshire Wind Power Project — the state's second largest wind farm — may be 170 miles away, its expansion is important for customers served by municipal light plants in Peabody, Marblehead and Ipswich.
The power generated by the Western Massachusetts wind farm goes into the grid, but given the local municipal utilities' significant ownership shares of project, the wind farm generates enough power to light 2,870 homes in Peabody, South Lynnfield, Ipswich and Marblehead.
The three light plants were among 14 municipal utilities that participated in the first phase of the wind farm project, which began commercial operation in 2011. The three were among 10 of those utilities that decided to take part in the second phase.
Construction started this past January on the two new turbines, and they reached commercial operation last month.
The wind farm is owned by the Berkshire Wind Power Cooperative Corp., which is made up of 17 nonprofit entities: The Massachusetts Municipal Wholesale Electric Company and 16 light plants in Ashburnham, Boylston, Chicopee, Groton, Holden, Hull, Ipswich, Marblehead, Paxton, Peabody, Russell, Shrewsbury, Sterling, Templeton, Wakefield and West Boylston.
MMWEC also operates the wind farm, under a contract with the ownership corporation, and manages its output and coordinates its operation with the regional power grid.
"Customers of participating (light plants) benefit by being served by a municipal utility participating in a carbon-free project such as Berkshire Wind," said Kate Roy, a spokesperson for MMWEC, which is also the joint action agency for the state's municipal utilities.
Roy said that this helps the light plants diversify their energy portfolios, as well as bolster their mission to support state and regional public policies to reduce carbon emissions under the Global Warming Solutions Act.
The first phase of Berkshire Wind was completed in 2011, and it involved the construction of 10, 1.5-megawatt wind turbines capable of generating a combined 15 megawatts of power.
Phase II involved the construction of two new turbines this year — each capable of generating 2.3 megawatts — for another 4.6 megawatts, for a total generating capacity of 19.6 megawatts.
This translates into enough power to serve 7,800 homes.
It turns out that the three North Shore light plants are taking a good chunk of the output from Berkshire Wind.
Peabody Municipal Light Plant, which serves customers in Peabody and South Lynnfield, represents about a 20% ownership in the overall project.
Marblehead had a 6.7% share of Phase I, and 13.5% of Phase II, for approximately 1.62 megawatts. Ipswich, likewise, had more than a 6% share in the first phase and then upped its share to nearly 20% of the second phase.
In the first phase, PMLP held a more than 18% ownership, said Bryan Howcroft, the light plant's assistant manager.
Peabody's share of the second phase is nearly 22%. This translates into 3.7 megawatts of clean power for its customers.
PMLP's share of output from the two new wind turbines alone can power 400 homes, Howcroft said, while both phases combined would be enough to power nearly 1,500 homes in Peabody and South Lynnfield.
The project means "clean energy for customers of PMLP for the next 20 years while keeping prices stable," he said.
The turbines used in Phase II, located in the towns of Hancock and Lanesborough, take advantage of technology advancements in wind generation over the past nine years, according to Howcroft.
"Improvements in blade technology allow the new turbines to begin operating and generating power at lower wind speeds, further increasing potential output for the wind farm," states a press release from Berkshire Wind Power Co-Op.
The wind farm represented a major investment in clean energy.
The first phase was a $64.7 million investment in the Berkshires, and it was financed by tax-exempt revenue bonds.
Phase II was financed with a $11.78 million private placement, according to Roy, who described the financing as "green bonds, through a bank." Green bonds, which come with tax incentives, are used to finance climate or environmental projects.
One advantage of wind power is it's a stable and predictable supply of energy, although it's still more expensive than natural gas.
Howcroft said the reason for this stability is because the cost to finance the debt for the wind farm and to maintain the turbines are ones that can be predicted, while the cost of power generation from sources like natural gas are harder to predict due to market fluctuations.
"We have a good handle on what the debt service and the maintenance is going to be," he said.
Jonathan Blair, the electric light manager of the Ipswich plant, echoed these sentiments, but also noted that wind power acts as a hedge against price spikes in the energy market.
The cost for wind power will pretty much be the same over the next five to 10 years, he said, while about 60% of the region's power supply comes from natural gas, the price of which goes up and down.
The power from the wind turbines goes into the power grid, similar to the way water from various sources goes into a reservoir.
Simply put, PMLP and the other light plants buy all the energy they need from various sources, and then they are credited based on how much power Berkshire Wind produces, Howcroft explained.
Roy, at MMWEC, said the individual lights plants' participation in Berkshire Wind is reflected in their overall rates.
"Ipswich is committed to carbon-free generation in the spirit of combating climate change," said Blair.
Blair, who also sits on the board of the Berkshire Wind Power Co-Op, said the project is one of the most productive wind sites in New England. The turbines are in operation on average about 40% of the time due to required wind speed.
He said the investment made in the first phase of the wind farm, such as access roads and other infrastructure, were leveraged in the second phase of the project. The additional turbines were put up on land previously cleared for the original project.
The Ipswich Electric Light Department, which had increased its share of Phase II to 19.1% for a total of 1.84 megawatts, also has two wind turbines of its own in town. One is owned jointly by the light department and the school department, and it generates 1.5 megawatts, Blair said.
A second, 2-megawatt wind turbine on Town Farm Road, which is owned by a private company, suffered an electrical fire in October 2018, and is in the process of being decommissioned.
Local share of Berkshire Wind Power Project
Municipal light plant Power by ownership % No. of homes lit
Peabody 3.7 megawatts 1,486 homes
Ipswich 1.84 megawatts 735 homes
Marblehead 1.62 megawatts 649 homes