A 2010 white paper by the Electric Power Research Institute (EPRI) identified 10 applications for energy storage across the entire electricity supply chain, including end-users. Below are some of the most promising:

• Frequency Response: While large scale use is a long term ambition for storage, “frequency response is the wedge into actual utility application in the field,” says Imre Gyuk, manager of the Department of Energy’s energy storage research program. Storage can provide much quicker performance than fossil fuel plants, which can take five minutes to respond. “In these five minutes the need may already be in the opposite direction,” Gyuk noted. Beacon Power, for example, says its flywheels can respond nearly instantaneously to operator control signals — up to 100 times faster than traditional generators. Beacon cited a recent study for the California Energy Commission which found that a 30-50 MW fast-response storage device could provide as much or more regulation capability as a 100 MW combustion turbine.
• Back-up Power: Researchers see large end users purchasing storage for backup power during grid interruptions. EPRI reports that diesel generators have a failure rate of more than 20%. A White House report released in August recommended that energy storage systems be a top priority for new investments to modernize the grid and improve reliability.
• Support for Intermittent Resources: Wind power produces only 10% of nameplate capacity in peak hours. “That alone is practically a mandate for storage,” said Gyuk. A 2010 study estimated a need of 0.8 to 1.5 MW of intra-hour balancing for every 10 MW of wind.
• Delaying Transmission and Distribution Upgrades: Storage can provide alternatives to grid upgrades in locations with slow load growth and infrequent maximum load days. These benefits could range from $150,000 – $1,000,000/MW-year, according to EPRI.