A Vermont utility has filed a plan with state regulators that would enable the power company to offer more customers battery energy storage to keep the lights on during outages.
Green Mountain Power (GMP), which has about 270,000 customers, said it wants to have its plan in place by 2030. GMP on Oct. 9 asked the Vermont Public Utility Commission to approve a capital expenditure of as much as $280 million across the next two years to bury transmission lines in some areas, and strengthen overhead lines with spacer cables so those lines can better withstand damage from falling trees. The utility also said it will supply homeowners in some rural areas with battery backup energy storage units.
“It is our responsibility to deliver a system that is always on for our customers,” said Mari McClure, president of GMP, in a statement. “No matter where you live or who you are, by 2030 a power system that’s there for you whenever you need it.” McClure said the strategy announced Monday will be less expensive for the utility and its customers than building more transmission lines or new power plants.
Savings For Utilities
A report from Boston, Mass.-based research firm Brattle Group, published in May of this year, said utilities could save as much as $35 billion a year by investing in distributed generation such as rooftop solar and residential battery energy storage to increase their supply of energy. Those measures—sometimes called virtual power plants—can be accomplished more easily and quickly, and at less cost, than building new power plants and transmission and distribution infrastructure.
Jigar Shah, director of the Loan Programs Office at the U.S. Dept. of Energy, in a recent interview with POWER said that increasing “adoption of distributed energy resources, and virtual power plants, is the best way … to support reliability of the power grid.”
GMP in April of this year filed a request with regulators to lift the cap on its residential energy storage programs to expand customer access to battery backup power, citing an increase in extreme weather in its Vermont service territory. The company’s Powerwall and Bring Your Own Device, or BYOD, battery backup programs have been capped at 500 new customers per program, per year. Most slots for the programs already are full for the next two years, with hundreds of customers on waiting lists.
The utility has leased Tesla Powerwall batteries to customers since 2015.
Expanding Battery Programs
McClure said expanding the battery programs is important, and said her group will ask regulators to support what GMP calls the 2030 Zero Outages Initiative statewide. The group said its cost could reach $1.5 billion; McClure said, though, “It’s keeping the lights on and it will eventually lower costs for customers.” GMP would control the batteries, allowing them to be programmed to store excess solar and wind energy from the utility’s system. The power would be dispatched during periods of peak demand.
McClure, in an interview with The New York Times prior to Monday’s filing, said, “Call us the un-utility. We’re completely flipping the model, decentralizing it.” GMP said its overall plan is a first-of-its-kind for a U.S. utility. The utility said the cost of its plan will be passed on to ratepayers, with the average homeowner’s monthly bill increasing by about 2%.
GMP has said extreme weather events have cost the utility about $115 million in the past decade, with 60% of those costs experienced in the past five years—including $45 million in the past year alone.
Regulators are expected to take six to nine months to review the utility’s plan. GMP has said if the plan is approved, it could begin work in the spring of 2024.
—Darrell Proctor is a senior associate editor for POWER (@POWERmagazine).