When it comes to hydropower, we’re pulled in two ways at once. We want more of this renewable electricity but we also want our rivers to be as natural as possible.

Good luck doing both.

“Dams are loved by some and hated by others,” is how Shannon Ames puts it.

Ames knows this first hand. She is executive director of the Low Impact Hydropower Institute, a Massachusetts non-profit that is trying to thread the needle on this issue by giving electricity-producing dams a seal of approval when they meet a series of environmental and social benchmarks lumped under the term “low impact.”

I learned of the institute’s existence because it is reviewing the certification of the Lower Penacook dam, one of three small hydropower dams along a short stretch of the Contoocook River in Penacook owned by Boston-based Essex Hydro. The dams are already certified but the measure has to be updated every five years.

“We’re glad to do it,” said Madeleine Mineau, chief operating officer of Essex Hydro in Boscawen, concerning the certification, which involves a lot of analysis and reporting. “We do work hard to be good stewards of the rivers, manage our projects in ways that we think are good.”

The certification is voluntary and separate from the mandatory licensing done by the federal agency FERC, but it’s worth more than just bragging rights. It can be used to show that a dam meets the environmental criteria needed to be paid through the Massachusetts Renewable Standards Program.

“That’s a large monetary driver,” said Ames. “That’s what we envisioned when the organization was begun, that there was recognition but also a way to monetize that, that allows an additional income stream which they can then reinvest.”

The certification covers eight areas, including water quality, maintaining sufficient flow for aquatic life, fish passage, shoreline protection and impact on cultural resources. They also give points for free public access to the water for recreation.

“We don’t have to balance energy needs with environmental needs, as FERC does. We put our finger on the scale as to the environment side, as opposed to energy,” Ames said. About 20% of applications don’t make it to certification.

The certification is noble and useful but it reflects the conflict of interests that I started with. After all, the goals would be met quite well if the dams just disappeared.

What wouldn’t happen in that case, of course, is any renewable electricity being produced. Which leads to the question of why we don’t have more of it?

New Hampshire has a ton of dams – more than 1,000. When I posted a map of them on Twitter and asked people to guess what all the black dots represented, one person said Dunkin’ Donuts.

Most of our dams are tiny, left over from the days of water-powered mills, and couldn’t be used for hydropower. They accomplish nothing other than making things harder for aquatic  life and threatening downstream properties when they fail. They could be removed and probably should be.

But some help control flooding and many provide recreation. These aren’t going away and it seems like we could attach turbines to at least some of them.

New Hampshire only has about 50 dams that produce electricity, and most are small. All but one of Essex Hydro’s 12 plants in Northern New England, as well as the two city-owned dams in Nashua that it operates, produce less than 5 megawatts, a cutoff for directly participating in the power grid market.

Even our “big hydro” isn’t all that big. The largest, Moore Dam on the Connecticut River in Littleton, produces 192 megawatts. Seabrook Station, for context,  produces 1,240 megawatts at full blast. One megawatt is the electricity used by about 700 to 1,000 homes at once.

Overall, the state’s hydropower dams are a small but useful part of our green-energy mix. I’ve always wondered why there aren’t more of them.

Mineau, it turns out, is a good person to ask. Her background is in aquatic ecology, and she worked as the first waterways manager for Nashua when that city took ownership of a small hydropower dam. She then was head of Clean Energy New Hampshire in Concord until moving to Essex Hydro. (Mineau was followed at CENH by the subject of last week’s column, Sam Evans-Brown.)

“I’m really excited to be back in small hydro. It often is overlooked as a form of renewable energy,” she said.

Mineau says there’s one main reason we haven’t taken more of our existing dams and put a turbine on them: It’s expensive because of regulation.

“There’s a really high regulatory barrier to entry. … To get a project licensed by FERC is a major undertaking. It’s more than almost anyone is willing to take on,” Mineau said. “A solar project does not have to do this level of studies.”

There are good reasons for this. After all, nobody will be killed by floodwaters if a solar farm suddenly fails. Plus, it’s hard to divert stream flow to spin a turbine without killing fish. American eels are particularly tough, Mineau says: “They’re long and skinny. Having them go through a turbine and survive is really challenging.”

Still, it’s a shame that we can’t take some of the dams that already block our rivers and use them to displace some of our pollution-producing electric plants. That would require a big reworking of federal regulations, which is easier said than done, but as the extent of the climate emergency becomes more apparent we’ve got to start doing more things that aren’t easy.

Pin It on Pinterest