Green Mountain Power sweetens the pot to boost battery storage
Green Mountain Power’s pilot program that encourages the use of home-storage batteries is being billed as a win for both Vermont consumers and Mother Earth. In the process, it should also make the road easier for the utility as it travels toward its goal of a carbon-free future for its pristine corner of New England.
The “Resilient Home” program offers a limited number of homeowners the unique opportunity to equip their residences with a pair of heavy-duty batteries that will bank electricity that can be used as an electricity reserve that Green Mountain Power (GMP) can draw on during periods of high demand that would otherwise require pricy spot-market power purchases from fossil-fuel peaker generators. The banked electricity can also be used to power homes left in the dark by an outage.
“We have a vision of a battery system in every single home,” said Green Mountain Power President and CEO Mary Powell. “Our Resilient Home pilot program does this by breaking the old utility mold and transforming the way energy is delivered to customers, increasing their comfort and convenience in the face of increasing severity and frequency of storms in Vermont due to climate change.”
The program launched this spring as wet, heavy snow continued to weigh down tree branches and powerlines in the mountainous state. It offers 250 of GMP’s 265,000 customers statewide the chance to acquire up to two storage batteries for their home for a fixed price of $1,500 or monthly installments of $30. The batteries of choice are the Tesla Powerwall; however, another 250 participants will be allowed to acquire their batteries from other manufacturers.
Resilient Home provides a level of comfort for the customer because they will be able to ride out the next storm with the lights and TV on. The battery system is seen by GMP as a stepping stone toward a renewables-based grid because the batteries could also send stored electricity back onto the grid at times when demand is particularly high. “If we can cut down the peak demand times, that’s where the big savings come for customers and the company,” said Josh Castonguay, GMP Vice President and Chief Innovation Officer. “It lowers our cost pretty substantially for buying peaking energy, which is more expensive and often dirtier.”
The batteries also offer the option of connecting to a rooftop solar array, which would help charge the batteries and even provide an overnight charging source for an electric vehicle. “The driving force for us is decarbonizing,” Castonguay told Daily Energy Insider. “Storing solar energy is a huge step toward that goal and saving our customers money in the process is also important to us.”
The program has an added incentive for consumers in an opportunity to change their billing to a flat-rate subscription, in which customers pay a specified monthly rate rather than a bill that fluctuates based on the age-old practice of a worker from the electric company manually reading the house’s meter. The battery strategy would do away with meters altogether since the batteries along with associated connections and software feed plenty of real-time data on electricity consumption back to GMP headquarters. This protocol would also allow consumers to monitor how much power they are using, enabling them to ease off if they feel that is necessary.
“You would still be getting the data you need, just in a different way,” said Castonguay. “The batteries provide the information on a second-to-second basis, but with a higher level of clarity.”
Castonguay said the flat-rate pricing would help GMP and its consumers with their financial planning by eliminating the spikes created by hot sticky summers and brutally cold winters. “Instead of having those ups and down, let’s fix the price of energy,” he said.
Customers would sign up for a specific price tier based on the average amount of electricity historically used per month. For example, the U.S. Energy Information Agency pegs the average household as consuming 900 kilowatts of electricity per month, which under the GMP subscription plan would cost customers $175 per month and allow them to use between 834 and 1,000 kilowatts per month. If they use more than that or less, the price tier can be adjusted, although Castonguay said, based on past experience, average monthly fluctuations would tend to stay within the established ranges.
GMP would also be able to phase out its current meter program where every house has a meter installed. The utility told DEI the installed cost of its current smart meters was about $110. The Resilient Home program should save Vermont customers an estimated $1.5 million, GMP said. A similar program in Oregon being offered by Pacific Power would eliminate $108 in annual meter-reading fees for its ratepayers and presumably trim its labor costs.
But the major benefit to GMP would be a nimbler grid able to react more quickly to weather-related demand fluctuations coupled with a ready reserve of electricity stored in garages all over the state. GMP, which has been installing Tesla Powerewalls for its customers since 2016, said battery storage already in service was drawn on during a single scorcher of a day last summer and saved ratepayers more than $500,000 that would have otherwise been spent on peaker power.
Castonguay said, “The most amazing part of this shift to battery-as-meter is that storage devices, like the Powerwall, have already proven incredibly useful in allowing us to manage the entire grid more effectively when you’re considering carbon and cost.”
