The bill , which is meant to help Massachusetts meet its goals for reducing greenhouse gas emissions, would require utilities in the state to work together to buy roughly 2,400 megawatts of clean energy, including hydropower for the first time. Those energy-generating resources would be enough to power an estimated 1.2 million homes.

“It’s too much, too fast, too risky,” said Susan Tierney, a former assistant secretary for policy at the US Department of Energy and onetime state secretary of environmental affairs. She estimates that Canadian hydropower could end up costing ratepayers billions of dollars.

Proposed state legislation that would bring large amounts of hydropower to Massachusetts from Canada could crash the regional power market and kill off other needed energy-generating resources, according to some environmental advocates.


The legislation is up for a hearing Tuesday before the Legislature’s Joint Committee on Telecommunications, Utilities, and Energy.

Tierney, a senior adviser at the consulting firm Analysis Group and self-described advocate committed to “decarbonizing” the state and the country, plans to present a report to legislators outlining her concerns.

Seth Kaplan, vice president for policy and climate advocacy at the nonprofit Conservation Law Foundation, said he, too, sees a need for changes in the legislation.

A key fix, Kaplan said, would be to tweak the bill to “explicitly foster” the use of clean energy technologies, such as wind turbines and solar panels. The state has mandated that Massachusetts have 2,000 megawatts of wind and 1,600 megawatts of solar in place by the end of the decade.

Another change in the legislation, he said, would be to find a way to ensure that hydropower projects, which use a mature technology, are not directly competing with less competitive renewable energy projects.

“If amended appropriately,” Kaplan said, “it could help us reach our climate and energy goals.”


Those goals include cutting greenhouse gas emissions — blamed for accelerating climate change — by 25 percent below 1990 levels by 2020.

Senator Barry Finegold, an Andover Democrat who cosponsored the bill, said he has been speaking with environmentalists, energy generators, and clean technology developers about the legislation, and revisions are in the works.

“What [Tuesday] is really about is trying to get people to air out wht they like and what they don’t like,” Finegold said.

For instance, he said, he’s cognizant of the concerns about how hydropower might squeeze out other generating resources, such as wind turbines and solar panels.

“We still want to grow our own renewables in the state,” he said.



Some renewable energy generators, however, say they are excited about this legislation and the boost they think it could give to their businesses.

Paul Gaynor, chief executive of the Boston renewable energy development company First Wind, said he sees the bill as an opportunity to pitch projects that will allow hydroelectricity to be a backup for the wind and solar farms his company builds.

“The wind’s not blowing all the time; the sun’s not shining all the time,” he said.

“So if you can combine these large Canadian hydro resources with large renewable resources in the region, then you can, essentially, fill up the transmission pipeline.”

Ed Krapels, the chief executive of Anbaric Transmission, said his company has at least two transmission line projects that it believes will help move wind power, in conjunction with hydroelectricity, across New England.


“The two together will be a pretty good package,” Krapels said.

Meanwhile, some believe that the state will be hard pressed to meet its pollution reduction goals without importing energy such as hydropower.

The Environmental League of Massachusetts recently released a report saying that its projections show the state is on target to cut greenhouse gas emissions by just 20 percent below 1990 levels by the end of the decade — 5 percentage points short of the goal.

“You’re really missing it by 20 percent of what you’d hoped to accomplish,” said George Bachrach, president of the group.

Bachrach said his organization supports bringing more hydropower to the state, but only if the environmental impacts from building dams don’t wipe out clean energy gains.

“We support hydro, but we want it to be the right kind of hydro,” he said. “There’s [also] a question of hydro becoming a too-dominant part of the energy mix.”

Erin Ailworth can be reached

at erin.ailworth@globe.com. Follow her on Twitter

@ail-worth.