A report released last week by Environment Rhode Island states that the Rhode Island State Energy Partners power plant is the dirtiest power plant in the state for its carbon dioxide pollution.

Environment Rhode Island put the report together using figures from the Environmental Protection Agency from 2007. The plant, which is located on Shun Pike in Johnston, is listed as emitting nearly 1.2 million tons of carbon dioxide that year.

Steven Stengel, a spokesman for NextEra Energy, which oversees the facility, said those figures are unfair.

“The facts of the matter are that RISE is actually the cleanest power plant when you normalize the data,” he said, explaining that the facility is the largest power plant in the state both by megawatt size and by the capacity factor.

“In 2007, the year that this press release was based on, we generated over twice the amount of power as the second largest plant in the state,” he said. “Because we generated more than twice as much it’s logical that the total amount of CO2 would be larger.”

As the global warming associate for Environment America, Sara Abrams said size shouldn’t exclude State Energy Partners from the most rigorous environmental standards possible.

“They shouldn’t be let off the hook,” she said. “The overall message of the report is that our energy infrastructure is outdated.”

Stengel maintains that NextEra is committed to operating efficiently, explaining that the Rhode Island plant uses combined cycle technology that most plants do not. In a combined cycle, heat that would normally escape from stacks is trapped to create steam, which is then used to “create extra generation without using additional fuel.”

“It is a very efficient way to generate electricity,” he said.

According to Environment Rhode Island, power plants are the nation’s largest source of global warming pollution. Here in Rhode Island, global warming is most immediately said to impact rising sea levels.

“In order to stop global warming and reap all the benefits of clean energy, we must require old clunker power plants to meet modern standards for global warming pollution,” said Rachel Pass, a field associate with Environment Rhode Island.

Combined, Rhode Island’s four power plants emitted close to 2.5 million tons of carbon dioxide in 2007. With RISE accounting for 1.2 million tons, that is the equivalent of 210,000 cars on the road.

The next highest polluter to RISE is the Manchester Street plant in Providence, at 682,000 tons.

“What the press release didn’t say was that our emissions rate,” Stengel said, explaining the rate to be the amount of carbon dioxide in relation to the amount of electricity produced, “is actually the lowest in the state.”

“Those are some pretty important facts that were left out,” he added.

Down the line, environmental advocates like Abrams and Pass would like to see the federal government put stricter guidelines on power plants like RISE. In the coming months, the United States Senate is scheduled to consider legislation to establish limits on global warming pollution, as well as put more incentives on clean energy.

Pass applauded the work of Senators Sheldon Whitehouse and Jack Reed for their efforts to pass energy efficiency legislation.

“We ask them to continue their leadership and advocacy on this issue and we also urge the EPA to finalize its proposed rule to cut global warming pollution from dirty power plants,” she said.