Hydropower could play a larger role in New England's energy mix as five of the region's states, including Massachusetts, move to import more of it — most likely from Canada — and at least one has passed a law that could allow electricity from large-scale hydrolectric dams to be classified as green as wind or solar energy.
Part of the goal, state leaders say, is to diversify an energy mix that in recent years has become increasingly dominated by natural gas, which now generates about 34 percent of the region's electricity, and nearly half of Massachusetts'. On Monday, Massachusetts energy officials are expected to detail a plan under which the state will work with Connecticut, Maine, Rhode Island, and Vermont to bring more hydropower into the region.
Meanwhile, Connecticut earlier this month adopted a new law that allows utilities, in certain cases, to count electricity purchased from large-scale hydropower projects toward meeting the state's aggressive clean energy goals.
Such proposals are raising concerns among environmentalists, who worry that an influx of cheap hydroelectricity could undermine efforts to spur the development and expansion of alternative energy technologies, which generate electricity at higher costs. They are also likely to spur debate over transmission lines needed to bring the power south, such as the controversial Northern Pass project, which would extend through the White Mountains.
"Bringing in more hydropower from Canada is a fine idea if it is part of a well thought out plan that adds to, instead of competes with, needed growth in wind and solar power," said Seth Kaplan, a vice president for policy and climate advocacy at the nonprofit Conservation Law Foundation.
In addition, Kaplan said, policy makers must also insist on "intelligently designed and sited transmission lines that are developed in cooperation with local communities."
While hydro has long been a part of the US energy mix, it has remained a small part of New England's electricity supply — first because of questions about how dams change water flows and aquatic habitats, and later over worries about how it would affect the market for other alternative energy resources. Hydro generation accounts for nearly 8 percent of net electricity generation in New England.
Massachusetts doesn't classify large hydro projects as a renewable resource on par with wind or solar — a designation that would qualify it for government incentives meant to help bolster still developing clean energy technologies. But Assistant Secretary for Energy Steven Clarke said officials here still think hydroelectricity could benefit the region.
"It emits fewer greenhouse gas emissions — far fewer than any fossil fuels," Clarke said, and that will help the state meet its goal to reduce greenhouse gas emissions by 80 percent below 1990 levels by 2050. "It can [also] help us diversify our fuel mix in New England."
Clarke said the joint hydropower initiative between Massachusetts and its neighboring states will begin with analysis of the market and recommendations for developing projects "in the very near term." Clarke said the group has already begun exploring several options, including Northeast Utilities' much-debated Northern Pass project, a transmission line corridor that would bring hydroelectric power from Canada's Hydro-Quebec into Southern New England.
Northern Pass developers are searching for a new route for the project, following criticism from environmentalists and residents that the line's original route would ruin a bucolic expanse of northern New Hampshire.
Despite the setback, Northern Pass supporters remain committed to a project they say will benefit New England in the form of cheaper, cleaner power.
"We're pretty confident that the Northern Pass project will provide just such an opportunity," said Martin Murray, a spokesman for Northern Pass, as well as Public Service of New Hampshire, a subsidiary of Northeast Utilities, which has headquarters in Hartford and Boston.
In a move that critics worry was designed to benefit Northern Pass, Hydro-Quebec, and Northeast Utilities, Connecticut Governor Dannel P. Malloy recently signed legislation extending his state's classification of renewable energy resources to large-scale hydroelectric projects. Large hydro may qualify in certain cases where officials determine there is a shortfall in the availability of other types of clean energy
That makes it more attractive for utilities to purchase electricity from hydropower projects in the Northeast and Canada because they may be able to apply it toward meeting the state's goal of getting 20 percent of electricity from renewable resources by 2020.
Daniel Esty, commissioner of Connecticut's Department of Energy and Environmental Protection, said the new law was not aimed at helping any particular project, but rather to help the state procure clean, cheap, and reliable power.
"We have just to our north a substantial resource that is very low emissions," Esty said. "People who are blindly opposed to hydropower are living in a 20th-century world where carbon emissions didn't matter and there was less concern about the impact of the price of electricity on our economy and pocketbooks."
Detractors of the law say they are worried it sets a precedent in which states are picking which types of energy resources will prosper. "The states should . . . allow any type of resource to compete to provide the best price and service for consumers," said Dan Dolan, president of the New England Power Generators Association.
Erin Ailworth can be reached at firstname.lastname@example.org. Follow her on Twitter @ailworth.