Marblehead Municipal Light Department has dramatically increased its carbon-free electricity portfolio from 42% to 65% in just one year, marking significant progress toward the town’s clean energy goals while simultaneously reducing costs for ratepayers.
The progress extends beyond environmental benefits. The average wholesale power cost decreased 3.4% year-over-year, dropping from 11.28 cents per kilowatt hour in 2023 to 10.9 cents in 2024. This creates what officials describe as a rare scenario where cleaner energy actually costs less.
To achieve this, Marblehead sources its electricity from a mix of nuclear, hydroelectric, wind and solar power. The town purchases nuclear energy from Millstone Nuclear Power Station in Connecticut and Seabrook Nuclear Power Plant in New Hampshire, which provide steady, around-the-clock electricity. Hydropower plays a major role, with sources like New York Power Authority Hydro (8,626 MWh), Hydro Quebec (6,588 MWh), FirstLight Hydro (6,707 MWh) and Brookfield Hydro (7,123 MWh) delivering renewable energy from rivers across the Northeast. Wind power comes from Berkshire Wind 1 (953 MWh) and 2 (1,739 MWh) and Hancock Wind (2,186 MWh), though its output fluctuates with the seasons. Marblehead is also expanding its solar capacity with power from the MSGT Cotton Solar Project (1,217 MWh).
Marblehead is committed to achieving net zero greenhouse gas emissions by 2040, a decade ahead of the Massachusetts state mandate for municipal light plants, which requires net zero by 2050.
“It wasn’t one thing that happened. It was a series of things that happened, all in the right way for us this year,” said Joseph Kowalik, general manager of MMLD.
The town secured several key additions to its power supply, including new hydroelectric contracts with FirstLight Energy and Brookfield Hydro that contributed over 13,800 megawatt hours of carbon-free electricity. Nuclear generation from existing contracts also increased significantly, with Millstone Nuclear providing 22.9% more power than the previous year (from 12,704 MWh to 15,616 MWh).
“This just doesn’t happen overnight,” said Tom Barry, director of Energy Markets at the Massachusetts Municipal Wholesale Electric Company. “This takes effort to be looking for opportunities that come across, not overnight. They come piecemeal.”
Lisa Wolf, chair of the Marblehead Light Commission, noted the strategic approach behind the town’s portfolio management.
The town’s strategy involves methodically replacing unspecified “commodity” power purchases with named, carbon-free generation sources. These targeted contracts now account for 30% of the town’s portfolio, representing a major shift in procurement practices.
Marblehead officials also completed a certificate trade with NextEra Energy, which operates the Seabrook Nuclear Plant. By exchanging different types of clean energy certificates, the town increased its officially recognized carbon-free electricity by nearly 6,800 megawatt hours without additional cost.
“It’s a classic win-win,” Kowalik said.
Despite the progress, challenges remain. The light department continues exploring potential sites for a 5-megawatt battery storage facility to reduce peak demand costs and provide resilience during outages.
“We’ve been providing electricity for 120 years. Batteries for storing electricity are a brand new component in the evolution of delivering electricity,” Kowalik said. “In Marblehead, there’s not a lot of free space around.”
Officials estimate that a battery system could save approximately $382,000 annually in capacity costs if properly managed to reduce demand during peak periods.
The town’s relationship with Hydro Quebec currently supplies 6,588 megawatt hours annually, accounting for about 5% of Marblehead’s total electricity load. Officials are considering doubling that allocation in future contracts.
The light department must also navigate the increasingly complex task of predicting and reducing consumption during peak demand periods, which directly affects costs. In 2024, the department called 84 potential peak events compared to an average of 40-50 in previous years, reflecting the growing challenges of load management.
“It’s only going to get harder as we go forward because of the intermittent nature of our power supply,” Kowalik said.
As Marblehead continues its carbon-free transition, officials emphasize that communication and community engagement remain essential components alongside infrastructure improvements.
“A communication strategy to underscore to residents to reduce their usage is as viable as putting energy storage in town,” Wolf said.
