Power plants throughout eastern Massachusetts are the largest industrial sources of greenhouse gas emissions linked to climate change in the state, according to new data from the U.S. Environmental Protection Agency (EPA).

(Embargoed until week beginning Jan. 29.)


Power plants throughout eastern Massachusetts are the largest industrial sources of greenhouse gas emissions linked to climate change in the state, according to new data from the U.S. Environmental Protection Agency (EPA).


The information comes from a website the EPA unveiled in January, publicly detailing for the first time emissions reported by the largest producers of carbon dioxide and related greenhouse gases in nine major industries.


All the top 10 sources of carbon dioxide emissions in the Bay State are power plants, including natural gas-fired facilities in Salem, Weymouth, Bellingham and Cambridge. The largest single producer of greenhouse gases in New England is the Brayton Point power station in Somerset, which is largely fueled by coal.


Similarly, the data shows power plants are the largest direct source of greenhouse gases nationwide.


Several owners defended local facilities, saying they take steps to be environmentally responsible, are highly efficient in meeting energy needs or turn waste into energy.


“It’s not a surprise that where you burn fossil fuel to make into electricity that is used every day to make our life a little better, you’re going to see carbon dioxide emissions,” said Jim Norvelle, a spokesman for the power company Dominion.


Dominion owns Brayton Point and the Salem Harbor power station, also one of the top 10 sources of greenhouse gases in the state. The Salem plant is set to close in 2014.


Norvelle noted there are no federal controls on carbon emissions, but Massachusetts is one of nine northeastern states that require power plants in the region to buy emission allowances. States use the proceeds help fund renewable energy initiatives.


Ben Wright, an advocate at Environment Massachusetts, said the new data from the EPA can help further develop the state’s plans to tackle carbon emissions.


“More data means we know better how to curb our greenhouse gas emissions,” he said. “You can’t reduce what you haven’t measured.”


The EPA’s ninventory covers facilities that produce upward of 25,000 metric tons of greenhouse gases, including carbon dioxide, methane and nitrous oxide, per year. That does not include emissions from agricultural operations, nor small-scale sources that add up, such as cars and trucks.


But the data from 2010 represents the vast majority of greenhouse gas emissions in the U.S., the EPA said. The agency said it was required to collect the data, which is from 2010, under a 2008 federal law.


The data can help businesses track and compare emissions in order to find efficiencies and inform state and federal environmental policy, the EPA said. 


The agency is expected to propose limits on greenhouse gas emissions from new or upgraded power plants some time this year.


Overall, Massachusetts fared far better than much of the U.S., ranking 40th out of the 50 states and Washington D.C. in total carbon emissions. The five states with the highest emissions were Texas, Indiana, Ohio, Pennsylvania and Florida.


Wright said Massachusetts has made headway in reducing emissions. In addition to participating in the Regional Greenhouse Gas Initiative, the state Green Communities Act set a goal of getting at least 25 percent of the state’s power from renewable sources by 2030. It also established energy efficiency initiatives to cut power use.


“The least polluting, cheapest energy is the energy we never have to produce in the first place,” Wright said.


The state Global Warming Solutions Act also calls for cutting greenhouse gas emissions 25 percent below 1990 levels by 2020, Wright said.


Here’s a look at some of the largest producers in the state:


Fore River Station, Weymouth


The Fore River power plant generates about 787 megawatts of power, according to its owner, Constellation Energy. It is the third highest direct source of greenhouse gas emissions in the state, producing 1.6 million metric tons of carbon dioxide in 2010, according to EPA data.


SEMASS Resource Recovery Facility, Wareham


This 95-acre facility burns trash collected by about 60 cities and towns in southeastern Massachusetts and Cape Cod to generate power.


Owner Covanta Energy, which also runs three other waste-to-energy plants in the state, views its operation as a type of renewable energy. SEMASS manages about 1 million tons of waste per year, said Covanta spokesman James Regan.


The SEMASS facility produced about 890,000 metric tons of carbon dioxide in 2010, according to EPA data. Covanta officials pointed to EPA studies indicating that waste-to-energy operations are a low source of carbon emissions nationwide.


Overall, carbon emissions from waste-to-energy plants are about half that produced by coal-burning plants, said Mike Van Brunt, Covanta’s director of sustainability. The process further cuts emissions by keeping trash out of landfills, where it produces methane, another greenhouse gas, he said.


“For every ton of waste we keep out of a landfill, we prevent all of the methane generation,” Van Brunt said.


The operation also recycles metals that otherwise would have to be mined anew, Regan said.


Salem Harbor


The Salem Harbor power station generates about 745 megawatts, enough to power about 186,000 homes, according to Dominion. The plant sits on 65 acres on the city waterfront.


The facility produced 1.3 million metric tons of carbon dioxide in 2010, according to the EPA data. That is far less than Dominion’s Brayton Point plant in Somerset, which pumped out 5.8 million metric tons of the gas the same year.


The facility uses three coal-fired generating units and one fueled by oil. Dominion is shutting down the plant and already closed two of its coal-burning units in December. The facility will close altogether in June 2014.


Norvelle said the company has made no plans for the future of the site. City officials have pressed Dominion to clean up the site.


Kendall Cogeneration Station, Cambridge


The Kendall Cogeneration Station has a production capacity of 256 megawatts, according to its owner, GenOn Energy.


The First Street facility produced roughly 717,000 metric tons of carbon dioxide in 2010, according to EPA data.


The facility uses natural gas as its primary fuel, with oil as a backup. The plant produces two forms of energy – electricity and steam, which is sold for heating and cooling, according to GenOn.


The company is constructing a new steam line allowing it to sell commercial steam to downtown Boston, said GenOn spokeswoman Paige Kane.


“You’re getting a twofer for the amount of fuel that you’re putting in,” she said.


Kane said the state encourages cogeneration under the Green Communities Act.


She also noted GenOn Kendall last year shared an EPA Environmental Merit Award, along with environmental groups, for making changes that will reduce the amount of water it draws and discharges back into the Charles River by about 95 percent.


International Power, Bellingham, Blackstone, Milford


International Power owns three power plants in the state. Two of the largest are in Blackstone and Bellingham, along with a smaller facility on National Street in Milford.


The Blackstone and Bellingham plants each produced more than 690,000 metric tons of carbon dioxide in 2010, according to the EPA. The Milford plant puts out about 179,000 metric tons of carbon dioxide.


International Power spokeswoman Julie Vitek said the Bellingham and Blackstone plants are among the largest power producers in the state and burn natural gas, “the cleanest-burning fossil fuel.”


Operators have changed equipment when possible to reduce carbon dioxide and other greenhouse gas emissions, Vitek said.


Further cuts in emissions probably are unfeasible, given that the plants are relatively new and already use technology that produces among the least emissions possible for a fossil fuel plant compared to the amount of power generated, Vitek said.


Wheelabrator, North Andover, Saugus, Millbury


Wheelabrator’s three facilities burn trash collected by surrounding municipalities to general power.


The Millbury facility produced about 475,000 metric tons of carbon dioxide in 2010, followed by about 410,000 metric tons in North Andover and 357,000 in Saugus, according to the EPA.


The emissions are “only a very small fraction of the total emissions in Massachusetts even without considering the benefits of the renewable energy power generation they provide,” Wheelabrator spokeswoman Melissa Lohnes said in an email.


For every megawatt of electricity produced from waste-to-energy plants, a megawatt of electricity is avoided from conventional fossil fuels, creating a net savings in greenhouse gas emissions, she said.


Lohnes also touted Wheelabrator’s efforts to recycle metals, meaning they do not have to be mined anew, and organic material as part of its commitment to reduce greenhouse emissions.


(Check out the EPA’s greenhouse gas inventory at ghgdata.epa.gov. David Riley can be reached at 508-626-4424 or driley@wickedlocal.com.)