Winter storms and historic flooding this year brought fresh impetus to an ambitious plan by Vermont’s largest electric company to end power outages in seven years by providing batteries to customers and shoring up existing infrastructure.
Green Mountain Power, which serves about 270,000 homes and businesses, submitted a plan to regulators on Monday asking for approval to invest $30 million to provide television-sized batteries to homeowners that would draw on clean energy from solar panels and wind turbines. The utility’s new Zero Outages Initiative aims to save on expensive grid repairs and expansions by investing another $250 million in stronger cables and buried power lines in vulnerable areas such as remote parts of central and southern Vermont.
The aggressive plan would be the most wide-ranging effort focused on batteries in the nation to date. It would broaden the utility’s current efforts already underway to distribute batteries to residents.
It would seem natural for Maine to adopt a similar program, given the poor service records of Central Maine Power and Versant Power, the state’s two largest electricity transmission and distribution companies. The companies ranked last in the eastern United States on the most recent J.D. Power customer satisfaction survey released last December, following a national trend of lower ratings driven in part by rising bills.
While there is interest in expanding battery use in Maine, utilities here said they are unlikely to pursue a similar initiative any time soon due to legal constraints and high costs.
Battery storage systems are a relatively new technology in the electric grid. They store excess electricity in large lithium ion batteries similar to those used in cars to provide power when less electricity is being generated or during an outage. Maine is in the early stages of developing battery storage for excess renewable energy, but it will need more capacity as the state transitions to clean energy to meet statutory climate goals, energy policy experts said.
Maine is the ninth state to set energy storage goals, but as of May it had reached only 21 percent of its goal for 2025. It had 63 megawatts of operational battery energy storage, according to the Governor’s Energy Office, with statutory targets to deploy 300 megawatts by 2025 and 400 megawatts by 2030.
The Green Mountain Power plan calls for the utility to invest about $1.5 billion over the next seven years that it would get back through rate increases. The utility said major storm costs are rising, and it needs a less costly way to plan for and respond to storms.
In the past 12 months it spent $45 million in repairs, the most to date. That money did not go toward preventing future outages. The utility said it could save by building resilience into its current system rather than building a lot of new lines and power generation plants.
“We are motivated to do all we can to combat climate change and create a Vermont that is sustainable and affordable, but we must move faster,” Mari McClure, Green Mountain Power president and CEO, said when the company filed the request with regulators.
But initiating a similar plan in Maine faces regulatory, legal and cost challenges, utility experts said.
“Batteries can clearly be used as part of a reliability solution, but need to be coordinated with a complex set of Maine regulatory overlays under state law,” said David Littell, an energy and environment attorney at the law firm BernsteinShur in Portland.
One challenge is that, unlike in Vermont, Maine investor-owned utilities are not allowed to generate electricity, potentially even through batteries. This is because Maine restructured its electric industry in 2000, requiring investor-owned utilities to only transmit and distribute electricity, not make it. In Vermont, utilities are responsible for both producing and delivering electricity.
Batteries, which go into operation during an outage, are generally viewed as generation resources, said Andrew Landry, deputy public advocate for Maine. That creates a question about whether Maine utilities could mimic Vermont’s move under the restructuring statute or whether the law would need to be changed.
“So that’s not an insurmountable barrier,” Landry said of the statute.
Efficiency Maine Trust, a quasi-state agency that also administers electric vehicle and heat pump rebate programs, would likely handle such a program, he said.A new law passed by the Legislature in its last session could open the door to a Vermont-like system in Maine. It directs the regulatory Maine Public Utilities Commission to look into utility ownership of battery storage and to file recommendations to the energy committee by Feb. 15, 2024.
The law, LD 1850, was signed by Gov. Janet Mills in June and goes into effect on Oct. 23.
Central Maine Power said it would welcome and support efforts at the Public Utilities Commission and the Maine Legislature to expand battery storage programs through pilot programs and policy proposals.
“We will be keeping a close eye on our Vermont neighbors,” Central Maine Power spokesperson Jonathan Breed said, “while noting that the potential cost for batteries could run between $10,000 to $18,000 per battery, per customer.”
He said the utility will also watch how Vermont regulators evaluate the overall cost effectiveness of the program.
Landry of the public advocate’s office said the program is “massively expensive.” He said he also isn’t sure whether it makes sense to place the batteries in each home or to assemble them in a substation or microgrid shared by many homes. And the batteries do not last as long as a backup generator, only backing up lost power from two to 48 hours, depending on the battery system.
“What they’re doing certainly will provide the ability to avoid shorter duration outages,” Versant spokesperson Judy Long said, “but it’s definitely not a replacement for investing in the grid.”
Rather than focusing on individual batteries for homes, Versant is working with the town of Eastport, the Island Institute and ocean turbine company Ocean Renewable Power to develop a microgrid in Eastport with battery storage to replace its failed backup diesel generator. Versant would distribute the energy from the microgrid to customers.
“We would need a partner to operate the battery,” Long said.
Versant also has access to battery storage in the former Great Northern Paper mill in East Millinocket that is owned by another company, Long said. The grouping of nine batteries are located next to an existing substation and can power about 9,000 homes for two hours.
Another company, NextEra Energy, has batteries on Cousins Island in Yarmouth.
“Batteries are going to play an incredibly important part of our clean energy transition,” Landry said. “But putting them at the customer level would be incredibly expensive and may not be the most cost-effective way to deploy batteries.”
Lori Valigra is an environment reporter for the Bangor Daily News. She may be reached at lvaligra@bangordailynews.com. Support for this reporting is provided by the Unity Foundation and donations by BDN readers.