1.2.5 Electricity generation

Electricity generation in Massachusetts has undergone a profound transformation since 1990. In the early 1990s, the state produced more than 40 million megawatt hours (MWh) annually, with oil and coal dominating the mix alongside a significant contribution from nuclear power. Natural gas was a smaller but rising contributor, while hydropower and biomass provided modest renewable output. This fossil-heavy mix reflected the legacy of mid-century investment in coal, oil, and nuclear infrastructure. However, by the mid-1990s, Massachusetts began to pivot toward natural gas, spurred by market deregulation, the availability of new combined-cycle plants, and mounting concerns over pollution from coal and oil.

Today’s electricity profile looks dramatically different. Total generation has fallen by half as demand flattened, and imports expanded from the New England grid. Coal and nuclear generation disappeared entirely, while utility-scale and small-scale solar surged. These shifts were driven by state policies such as renewable portfolio standards, federal tax incentives, declining solar costs, and public opposition to coal and nuclear. The result is a generation mix increasingly dominated by natural gas and solar, reflecting both the challenges and progress in Massachusetts’ energy transition.

1. Electricity generation by source: This indicator presents annual electricity generation in Massachusetts, disaggregated by the energy source used to produce the electricity. The data come from the U.S. Energy Information Administration’s State Energy Data System (SEDS), which compiles information from utility reports and other official sources. Generation is measured in megawatt-hours and reflects electricity produced within state boundaries, not imports or exports. While SEDS only reports utility-scale solar generation (greater than 1 MW), additional EIA datasets have been incorporated to include small-scale solar (less than 1 MW). This provides a more complete picture of total solar generation, particularly important in Massachusetts where rooftop and other distributed systems are significant contributors. The Biomass category includes “Wood and Wood-Derived Fuels,” which refers to solid woody materials such as wood chips, pellets, and mill residues, and “Other Biomass,” which includes non-wood biogenic sources such as municipal solid waste, landfill gas, and biogas from wastewater treatment.

Publication Date: August 2025