(NBC News) -- Long hailed as a game changer that will allow unlimited amounts of wind and solar energy onto the electric power grid, big rechargeable batteries are beginning to move out of research labs and find a home amid the real-world tangle of smokestacks, turbines and power lines. Today, the reality falls short of the hype about fossil-fuel-free electricity — but experts say that future could be in store.
For the foreseeable future, electric utilities will rely on coal, gas and nuclear power plants to provide a steady base of power, according to Paul Denholm, a senior analyst at the National Renewable Energy Laboratory in Golden, Colorado. But batteries can help balance the flow of electricity as demand ramps up and down throughout the day.
"That is where the hot applications are right now for energy storage," he told NBC News.
Traditionally, utilities maintain a little "wiggle room" on their system, he explained. For example, they might run power plants at 90 percent capacity, so that extra juice can be made available when a dark cloud passes overhead and thousands of people flick on their lights.
Operating power plants that way is hard on a system. It's inefficient, and expensive. Batteries, which can add extra juice nearly instantaneously, are a more cost-efficient way to keep the grid humming. What's more, this load leveling usually only requires 15 to 30 minutes' worth of energy. "You can have a relatively small storage device and make a decent amount of money on it," Denholm said.
While the market for this type of battery usage is limited, it is an entry point for a technology in need of experience on the grid, he explained.
Load leveling is precisely what Avista Corp. in the Pacific Northwest plans to do with the 3.6-megawatt capacity vanadium flow battery it is purchasing for its grid in Pullman, Washington, with the help of a $3.2 million matching grant it received in July from Washington state to advance energy storage technology.
In theory, the battery from Mukilteo, Wash.,-based UniEnergy Technologies could be installed next to a wind farm to store excess generated electricity, for occasions when wind speeds go so high that turbines are shut down to prevent damage, or when the wind suddenly dies out.
"But that carries with it a lot of cost [for] a single purpose … and you still have to send it across the transmission lines to get it to the load," Curt Kirkeby, a senior electrical engineer and technical strategist with Avista in Spokane, Washington, told NBC News.
Rows of battery racks are arrayed at Portland General Electric’s Salem Smart Power Center in Salem, Ore. PGE is a participant in the Pacific Northwest Smart Grid Demonstration Project, which is using the center’s 5-megawatt energy storage system to test smart-grid strategies.
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