Energy Sources at Ends of Lines Could Benefit Everyone
Boothbay, Maine has a message for end-of-the-line towns around New England: you could make the whole grid stronger.
Boothbay Harbor is a quaint village on the coast of Maine, where lobster boats and whale watches come and go, and rigging clinks against the masts of sailboats. It’s a scene that could just as easily be found in Provincetown or Vineyard Haven.
New England is facing an energy crisis, and the problem largely stems from the region's reliance on natural gas. But towns like these – peninsulas, islands, and others at the ends of transmission lines – face the added challenge of getting electricity where it’s needed, when it’s needed, with a limited number of transmission lines to do the job. It’s getting harder and harder to do reliably.
Historically, Maine has been what’s known as a winter-peaking state, meaning the highest demand for electricity happened on cold, winter nights. Not anymore. Since 2004, peak demand has come on hot summer afternoons.
The state’s energy flow is also peakier – or less constant – than it used to be. And it’s not just Maine. Data from the Energy Information Administration indicates that the disparity between peak and off-peak energy usage in New England has been steadily growing over the past twenty years.
In a region renowned for cool ocean breezes and moderate summer weather, there’s a surprising culprit for these shifts: air conditioners.
“The air conditioner is now in all the office buildings, it’s now in most of the commercial locations,” says environmental lawyer Steve Hinchman. “You can’t go into a store that isn’t air conditioned.”
And it’s not just the supermarkets and big box stores. During peak tourist season, many of Boothbay’s boutiques and galleries have their doors wide open, lights on, and air conditioners going full blast.
That’s particularly worrisome for the Boothbay region, because there is just one high power transmission line that feeds the three towns at the end of the peninsula. Maine’s Public Utilities Commission projects that the line will soon be overloaded at times of peak demand.
Officials considered adding another transmission line. At an estimated $18 million, it wasn’t going to be cheap. And it was likely to be contentious as well.
“There’s no empty land to bring it down,” explains Hinchman. “It would have required eminent domain and battles with lots of different land owners who don’t want to see power lines in their view of the spectacular Maine coast.”
Instead, Grid Solar - the company where Hinchman is currently general counsel – stepped in with a less expensive option. The plan is to reduce the size of those summer afternoon peaks and then make up any remaining shortages with local sources of electricity.
“It’s mountain-top removal, if you will,” jokes Hinchman. “You’re lowering the peak, eliminating the peak that requires you invest millions and millions of dollars in new transmission to serve peak loads that only occur five to thirty five hours a year.”
Since air conditioners are the source of the problematic peaks, they’re a logical place to start whittling them down. Using state funds, Grid Solar paid a company called Ice Energy to replace air conditioners at nearly three dozen area businesses with what are essentially industrial-sized ice makers.
An Ice Bear looks like a large air conditioner – a big metal box with an intake fan. But there’s no energy-intensive condenser inside, just a block of ice. When cooling is needed, a fan blows air over the ice and into the building. It takes less energy to make the ice, plus it’s made at night, when ambient temperatures are lower and energy demand is less.
Such load shifting helps smooth out the peaks and troughs in energy demand. But, by itself, it’s not enough to solve all the region’s electricity problems. The Public Utilities Commission estimates Boothbay needs to generate 2 megawatts of electricity in order to avoid line failure during periods of peak demand. So, Grid Solar put out a call for proposals and funded a range of projects, including a generator, a battery, and nineteen solar installations.
There’s a 25 kilowatt solar system on the Town of Boothbay Public Works building, and more panels on the recycling center next door. The fire station, the YMCA, several hotels downtown, and some private homeowners are also in on the project. It’s a mish-mash of sizes and locations, but it’s not haphazard.
“Electricity follows the path of least resistance,” explains Hinchman, as he looks at the solar panels on one municipal building. “It will fill the load on this building, and then the excess will be exported onto the grid. And it will travel on the local [wires] to the next building on the street, and fill the load, and then to the next building on the street.” And so on, and so forth.
Because of the way electricity flows, Hinchman says they carefully placed solar panels near each of the three substations serving the Boothbay region. That way, the locally generated electricity pushes back evenly against the flow of electrons coming down the transmission line, freeing up power for towns upstream. It’s like starting those summer afternoons with a glass half-full, and Hinchman says it makes the entire grid more resilient.
“The more you spread your distributed resources out to the end of the line,” says Hinchman, “the higher the benefit to the system.”
Solar is well-suited for meeting summer spikes in power usage, and comes with the added advantage of providing free electricity throughout the year – not just during those few dozen hours of highest demand.
But, just in case the solar panels aren’t enough to meet Boothbay’s peak needs, there’s a new diesel generator in the Industrial Park. Grid Solar is also working on installing a lead-acid battery that could charge at night and supply a few hours of electricity in the afternoon. And Hinchman says they can always add something else, if the need arises.
“We can walk in lockstep with load,” he says. “You don’t have to go out and spend $18 million on a line ten years in advance of needing it.”
Solar panels and Ice Bears don’t make much noise, but they sure are creating a buzz. Residents and town officials are enthusiastic about the project.
“The only complaint I’ve heard from some of the locals is [that] the solar panels going up on some of the hotels take away from the quaint, Maine feel of the town,” recounts Brooke Hubner of the Boothbay Harbor Chamber of Commerce. “But it’s more just your crotchety New Englanders that say that stuff.”
State legislators also seem pleased with Boothbay’s progress. This summer they changed Maine state law to require that such local generation schemes be considered whenever part of the grid needs upgrades.
This report is the 3rd in a 10-part series about our energy system, called, “Power Source: Where People and Energy Connect.”