Batteries: An Expensive Way to Store Energy

Although energy storage is getting a lot of press as a great way to avoid peak energy spikes, using batteries for energy storage is not the most economical, according to The New York Times.

“It costs hundreds of dollars to store a kilowatt-hour of energy in a battery, while nationally the average retail price of a kilowatt-hour is about 11 cents,” states The NY Times. “On the wholesale market, even buying low at off-peak periods and selling high could earn a battery owner perhaps 25 or 30 cents for each $400 or so invested.”

Jay Apt, executive director of the Carnegie Mellon Electricity Industry Center, told the newspaper that prices would have to fall by 90 percent, from the current range of $300 to $500 per kilowatt-hour of capacity down to $30 to $50 for battery storage to be profitable. For commercial uses, as opposed to utility energy storage, Apt touts low-tech energy storage technologies such as big containers of ice in building basements or tanks of molten salt.

For example, buildings can use their air-conditioning systems to freeze water into ice in the middle of the night and then use the melting ice during the heat of the day to cool the air.

During an Energy Manager Today webinar, Guy Frankenfield, manager with TES & Biofuel Tanks DN Tanks, said chilled water storage tanks can act as thermal energy storage units for companies to manage their electricity loads. For example, in Texas the wind often blows more at night, generating wind power at a time when it’s least needed by most companies. But that energy can chill water during off-peak periods, which can then be stored for peak periods.

Photo: Battery via Shutterstock