Cambridge Extends Historic Renewable Energy Opportunity to Residents, Businesses


12/17/2024 • 5 days ago

The City of Cambridge has taken another significant step toward a greener future by creating a new, utility-scale renewable energy project. As a result of a virtual power purchase agreement (VPPA), a new solar farm is being built in Illinois and Cambridge will receive credits for making new renewable energy available to the grid.

This is the largest-ever VPPA agreement directly by any U.S. city and the first of its kind in the Northeast. The Prairie Solar project will produce electricity for Illinois residents.  Cambridge residents and businesses who get their energy through the Cambridge Community Electricity Program will earn credits (Renewable Energy Certificates) for the emissions reductions from the solar farm. 

This agreement follows the City’s November 2024 announcement of its first VPPA, signed through the local Consortium for Climate Solutions, for a new wind farm in North Dakota. In that agreement, the City will earn Renewable Energy Certificates for its own government operations carbon emissions once the project is operational. These credits are a critical piece of the City’s carbon emission reduction strategy.

Instead of waiting for Massachusetts' grid to get cleaner--already required by state law--Cambridge and others are proactively helping build new renewable energy projects. 

“The scale of what Cambridge has done to build new renewable resources in North Dakota and Illinois is truly exceptional, together, nearly three times the size of BU Wind,” said Dennis Carlberg, Chief Sustainability Officer, Boston University. “Since the New England Grid is one of the cleanest in the country, and these projects are in grids slower to transition, they should reduce nearly twice the global greenhouse gas emissions than if the same projects were located in the greening New England grid. This is truly remarkable work that I hope others will replicate.”

Cambridge is one of 170 cities and towns in Massachusetts that uses its purchasing power to offer electricity to its residents and businesses with stable prices that are often lower than the utility rate. It supports the development of renewable energy projects – locally, regionally and nationally. While Eversource’s prices change seasonally, the Cambridge Community Electricity Program locks in rates for several years to protect residents and businesses from fluctuating electricity prices.  There are no contracts or penalties for changing enrollment.

Why is this happening? With 120,000 residents in just 6½ square miles, Cambridge is one of the densest cities in the US and cannot produce all of its electricity through renewable sources within city limits.

“Renewable projects, like this VPPA, make the most difference because they replace more carbon-intensive fuel sources, like coal, compared to Massachusetts where most of the electricity is fueled by natural gas,” explained Ellen Katz, Department of Public Works, City of Cambridge.  “Combining strategies like VPPAs with local investments are critical to Cambridge’s strategy to reduce the use of fossil fuels quickly and maximize its global impact on carbon emissions.”

How it works:  The Prairie Solar project in Illinois is expected to begin operating in summer 2026.  Located near a former coal mine, Illinois residents will benefit from local economic investment and improved air quality, along with the electricity produced by the solar project.  By committing to purchase Prairie Solar’s renewable energy certificates, Cambridge and other utility-scale energy buyers allowed the solar developer to secure the financing required to construct the project.  MN8 Energy (MN8) will own and operate the Prairie Solar project. The VPPA was facilitated by Boston-based Sustainability Roundtable, Inc. through their Net Zero Consortium for Buyers (NZCB).

“Preventing carbon emissions in Cambridge or Illinois has the exact same impact on the global climate,” said Julie Wormser, Chief Climate Officer, City of Cambridge. “It will allow us to make a bigger difference more quickly and cheaply than say pursuing smaller rooftop solar within city limits, while providing local benefits to people in Illinois.  At the same time, we are making significant investments in Cambridge to phase out all fossil fuel use."

As an example, the City continues to invest in building and renovating municipal buildings to maximize their energy efficiency, run on clean energy, and use onsite solar panels and geothermal heat pumps. Cambridge also runs a variety of free programs to help residents and businesses phase out fossil fuel use in their buildings.

Why now?  Multiple communities--including Cambridge--have committed to phasing out all fossil fuel use by 2050.  Most carbon emissions in Cambridge come from buildings and transportation.  Like other communities, Cambridge's electricity largely comes from Massachusetts' electrical grid, which is currently powered by 1/3 renewable sources and 2/3 fossil fuels and is slated to be 100% renewable by 2050.

“The City of Cambridge remains steadfast in our commitment to slowing climate change and meeting our ambitious sustainability goals,” said Cambridge City Manager Yi-An Huang. “We are also excited to amplify our impact by increasing the amount of renewable energy getting built – whether it’s here in Cambridge or other parts of the country.  I am grateful to staff in our Community Development, Public Works, Finance, and Law Departments for successfully pursuing this breakthrough agreement.”

Launched in 2017, the Cambridge Community Electricity Program includes the majority of Cambridge’s residential and small business electricity accounts.  Enrollment is automatic with an opt-out choice.  Once the Prairie Solar project is operational in 2026, 55% of the power in the Standard Green option will be supporting clean, renewable energy. Participants can already choose to purchase 100% renewable energy at a higher price.