Hydroelectric station employs 5-billion-gallon ‘battery’ for energy storage
A recent energy-storage initiative launched by the state of Massachusetts has prompted writer Bruce Gellerman to tour New England’s largest “battery”—a term Ben Franklin applied to an electric-energy storage device (in Franklin’s case a series of linked glass capacitors). Writing at WBUR, Gellerman describes New England’s largest “battery” as the 5-billion-gallon upper reservoir that powers the 1,200-MW Northfield Mountain pumped storage hydroelectric station.
The station provides power during peak load periods and pumps water back into the upper reservoir during off-peak hours. The facility was originally conceived to balance the load on the nearby Vermont Yankee nuclear power plant. That plant closed two years ago, and now FirstLight Power Resources—the operator of the Northfield Mountain station—buys cheap power from the grid during off-peak hours and sells it back at a profit during periods of high demand.
Gellerman quotes Gus Bakas, director of Massachusetts hydro operations for FirstLight Power Resources, as saying, “I think the goal of our facility would be to look at the opportunities to purchase purely green, renewable power and be able to supply green power to the grid.” The facility is now undergoing relicensing to operate for an additional 50 years.
Gellerman writes, “The U.S. Department of Energy has big plans for battery systems like this. Pumped hydro is the most cost-effective way to store electricity. Ninety-nine percent of the bulk electric storage in the world is pumped hydro, and by 2050 the department wants to nearly double the amount now produced: enough to serve nearly 25 million homes.”
The recent Massachusetts state initiative, announced in September, is focusing on electrochemical batteries, flywheels, and thermal and compressed-air technologies. A study found that Massachusetts customers during 2013 through 2015 purchased 40% of their electricity during the top 10% most expensive hours.
“By embracing energy-storage solutions, Massachusetts ratepayers will be able to realize hundreds of millions of dollars in benefits over the next decade while helping to unlock the true potential of clean energy for our state,” said Energy and Environmental Affairs Secretary Matthew Beaton, in a press release. “Increased energy storage capacity will not only lower our state’s peak demand, but increase overall energy system efficiency, leading to lower carbon dioxide emissions.”