While solar panels fly up on rooftops and fuel cells are installed throughout Connecticut, another type of renewable energy generation is slowly gaining steam in the state.
Recent changes to state law governing renewable generation has increased interest in re-energizing old dams along Connecticut’s rivers and streams, with the potential to bring rundown and polluted properties back to productive use. The projects not only carry the potential to produce clean electricity but also leave the possibility for commercial and residential development along these waterfront properties, even though the projects can take significantly longer to complete than installing a solar array or a fuel cell.
Connecticut has at least 68 old dams along its rivers — most built in the 1800s or early 1900s to power mills — with the potential to be re-energized to produce 1 megawatt or more of electricity, according to the Hartford trade group Renewable Energy & Efficiency Business Association.
Berlin utility Connecticut Light & Power already has awarded six renewable energy credit contracts to dam re-energization projects, and legal changes that allow dam owners to sell their electricity to a bigger customer base has made the projects more economical.
“It is underutilized technology,” said Paul Michaud, REEBA’s executive director. “They were used to power old mills, but now they can be used to power the grid.”
Connecticut doesn’t allow for the construction of new dams for renewable-hydro energy, but state law says projects that use existing run-of-river dams are considered renewable. With changes in the law over the past two years, dam owners now can increase their output from 5 megawatts to 30 megawatts of electricity — enough to power 24,000 homes — and can sell that electricity directly to municipalities, instead of having to rely on the real-time market or landing long-term, power-purchase contracts with utilities.
“The changes in the law have changed the level of interest in dam projects,” said Jessie Stratton, director of policy development for the state Department of Energy & Environmental Protection. “The idea was if we can generate electricity from streams, that would be great.”
Jean-Paul Gauvin is one of a handful of developers around the state looking to re-energize an old dam. His Glen Falls Dam project in the Moosup section of Plainfield seeks to get a working generation turbine alongside a 6.5 acre solar array, producing 2.5 megawatts of combined hydro-solar power.
Gauvin has been working on his Moosup project since 2006. The development, however, was stalled by the downturn in the real estate market in the late 2000s and storm damage to his dam in 2010. But he has been able to move quicker than other dam re-energization projects because his property already has a license from the Federal Energy Regulatory Commission to sell electricity, helping him avoid much of the state regulatory paperwork.
“This one has a FERC license to it, which helps,” said Gauvin, whose license expires in 2032. “There are so many people who put in so much work to get that license, I thought it would be a shame to let it go.”
Gauvin’s hydro-solar project is the first phase of his development plans for the Moosup site. Once the renewable energy installations are complete next year, he plans to build a residential village powered by the electricity. Initial plans call for 60 condominiums.
Gauvin’s Moosup development used to be a U.S. Environmental Protection Agency Superfund site, as the former Brunswick mill left water and soil contamination from 80 years of industrial operations. Before Gauvin took control of the property, EPA spent $3.4 million cleaning up the contamination.
“My deal with the EPA was to get this property back on the tax roll,” Gauvin said.
Brownfield development
Most of the 68 Connecticut dams with the potential for re-energization are on some kind of contaminated property, Michaud said, and the energy projects can remove that contamination and turn what were previously abandoned or neglected sites into functioning facilities.
The energy projects also carry the extra environmental benefit of installing fish ladders, Michaud said. Because nearly all of the dams in Connecticut were built before there was a strong understanding of fish habits, they don’t have access points for fish to swim past the dams upstream to spawn.
Independent of any re-energization projects, DEEP has been working to install fish ladders at all Connecticut dams without one. In May, for example, the State Bond Commission awarded Bloomfield a $600,000 grant to install a fish ladder and make improvements to Filley Park.
The fact that private developers re-energizing dams are installing fish ladders on their own is just icing on the cake, Stratton said.
Greg Renshaw, who is re-energizing the Cargill Falls Mill dam in Putnam, is installing a fish ladder in addition to using turbine generation technology, which won’t harm fish, to make his 875 kilowatt dam as environmentally friendly as possible.
His $24.5 million project includes not only the dam but 82 units of residential and 50,000 square feet of commercial space.
Renshaw received $8 million in state and federal tax credits for his project, another $5 million in Connecticut competitive housing assistance money, and — like Gauvin — a 15-year contract from CL&P to buy the renewable energy credits from the hydro project when it’s up and running.
Lenders wary of dam re-energization
That financing is important because banks and major investors shied away from the Putnam project because it was Renshaw’s first dam re-energization. Unlike Gauvin’s project, Cargill Falls doesn’t have a FERC license. Renshaw has been working on the development for 12 years and it is expected to be complete in April 2016.
“Once you really figure out these mill projects and complete one, you have banks that want to work with you because you have a track record,” said Renshaw, who added he already is negotiating to start work on more local dam re-energization projects.
Even though there will be far fewer dam projects than solar projects — CL&P has awarded about 200 renewable energy credit contracts to solar arrays vs. six for dams — these projects still are important to Connecticut’s overall energy profile, Michaud said.
Unlike solar that only generates electricity when the sun is shining, hydro projects generate power constantly, feeding the grid regardless of conditions. A 150 kilowatt hydro system generates as much power as a 1 megawatt solar system.
“The dams are more expensive upfront because of the hard costs compared to solar,” Michaud said. “However, they are much cheaper to operate once they get up and running.”
The dams already exist, so they might as well be put back into use, Stratton said.
“This Class I hydro isn’t going to be a big contributor to our renewable energy generation, but if it is already there and it is economically viable, we should use it. Otherwise, it is a waste,” Stratton said.
