In 2021, renewable energy sources provided 29% of the net electricity generated within Massachusetts. Renewable energy made up 25% of the state's total generating capacity.
Up until 2008, hydroelectric and biomass facilities in Massachusetts produced all utility-scale renewable energy. However, by 2021, Massachusetts ranked ninth in the US for solar-generated power. This also comprised small-scale generation. As of mid-2022, the Bay State has an installed solar capacity of about 3,178 megawatts.
In Massachusetts, biomass has been used to produce electricity for many years. In 2021, it contributed about 5% of the entire in-state energy net generation. During this period, it was the state's second-largest renewable electricity source.
Biomass power plants in Massachusetts can generate 284 megawatts of electricity. Municipal solid waste is the fuel source for biomass plants with the most significant production rates. The third-largest portion of the state's renewable energy came from hydropower, accounting for about 4% of the state's net production. Massachusetts has two hydroelectric pumped storage facilities and 31 conventional hydroelectric generating plants.
On the state's waterways, numerous dams were constructed in the 19th century. This was done to give industrial mills mechanical force. The tallest falls on the Connecticut River, known as South Hadley Falls, are in central Massachusetts, close to Holyoke. There is the 1893-built hydroelectric power facility that is still in use today.
In 2021, 1% of all net energy production in Massachusetts came from wind power. As of 2023, the state has 23 utility-scale wind power facilities with a total generating capacity of 106 Megawatts.
In Massachusetts, onshore industrial wind development is most prevalent along the coast.
However, two projects in the mountains close to the state's northwest border are home to the biggest wind farms. This area also has the largest portion of the state's wind-generating capability. The state passed a law in 2016 requiring utilities to hold competitive solicitations for offshore wind capacity. These utilities are also expected to sign cost-effective, long-term contracts for offshore wind energy production totaling about 1,600 megawatts by mid-2027.
A mandate to add 1,600 megawatts by 2035 was granted to the state's Department of Energy Resources in 2018. Since then, Massachusetts has raised its offshore wind energy targets. By 2027, the state plans to request bids for 5,600 megawatts of offshore wind energy.
The area around Cape Cod and the islands of Martha's Vineyard and Nantucket has the finest offshore wind resources. The first offshore wind farm is projected to have a generating capacity of 800 megawatts. The property is currently under construction 15 miles south of Martha's Vineyard. It is expected to start running in 2024. In federal offshore regions, more wind projects are being developed south of Martha's Vineyard.
The Renewable Portfolio Standard (RPS) in Massachusetts was initially implemented in 2003 and later extended in 2009. Electricity market distributors and investor-owned utilities operate under a two-tiered structure.
The first category, Class I, includes all proposed renewable resource facilities, while the second category, Class II, includes all currently operational facilities. The RPS mandated that by 2015, suppliers must have acquired at least 15% of their revenue from Class I renewable resources. From then on, this will rise by 1% annually. Solar and waste-based energy sources must provide a percentage of total electricity sales.
Massachusetts has its version of the Renewable Energy Portfolio Standard. By 2020, the plan was to have alternative energy account for 5% of the electricity produced in the state. After that, the percentage would rise by 0.25 per year.
CHP initiatives and renewable technologies like biomass and geothermal heat pumps are examples of alternative energy sources that can be used to produce thermal energy. To complement the RPS, the state has implemented the Sustainable Energy Standard (CES). The CES mandates that all electricity sales must originate from clean energy sources. Power sources such as hydropower and nuclear are included.
Those sources must reduce greenhouse gas pollution over their entire life cycle by at least half compared to the most efficient natural gas-fueled power plant. By 2018, the CES mandated that 16% of all revenue come from renewable energy. The market share of clean energy is projected to grow by 2% yearly, reaching 80% by 2050.