Back in March, utility American Electric Power floated the idea of "community energy storage" – small batteries mounted on power poles that could keep neighborhood distribution grids running smoothly and cut down on the demand for peak power (see Green Light post).
Now AEP – backed with $75 million in Department of Energy smart grid demonstration grants – is moving forward with the project, the first in the country to attempt distributed battery storage at a large scale.
Chicago-based S&C Electric Co. will oversee the community energy storage project, which includes distribution automation systems and integrating renewable power sources like rooftopsolarpanels.
That, in turn, is part of AEP Ohio's larger GridSMART project, meant to bring smart meters and other smart grid systems to about 110,000 AEP customers in Ohio (see Silver Spring, AEP Team on Smart Grid).
As part of that project, S&C will install five to 100 25-kilowatt lithium-ion batteries in neighborhoods that tend to see high levels of strain in delivering peak power loads, said Brad Roberts, power quality systems director for S&C.
While the DOE gave out a total of $185 million to 16 energy storage projects in its smart grid demonstration grant funding announcement last month, AEP's project – along with a smaller, $5 million project at Detroit Edison – are the two aimed at smaller-scale community storage, Roberts said (see DOE Doles Out $620M for Smart Grid).
Detroit Edison plans to use lithium-ion batteries from A123 Systems, the Massachusetts battery maker that has received hundreds of millions in federal loans to build a battery plant in Michigan.
As for S&C, it hasn't revealed which vendor it's using for its 25-kilowatt lithium-ion batteries, Rogers said.
AEP is already a pioneer in storing electricity on the grid, though to date it's done so using cargo container-sized, superheated sodium sulfur batteries to do it. Those 1-megawatt to 2-megawatt batteries are typically located at substations, and provide backup power for minutes or hours, depending on the need (see GridPoint to Manage Wind Power Battery Storage).
When it comes to getting the same level of functionality out of 50 to 100 smaller batteries scattered around a distribution grid, "It's a real challenge to put that much technology in a box that's tamper proof and has a lot of intelligence in it, and communicates via radio to the network, and can respond to the utility telling it what to do, just like that 2-megawatt battery did at the substation," Roberts said.
But the distributed nature of those batteries also offers AEP some additional benefits it can't get from big, centralized storage, he said. For example, distributed batteries can better balance very localized sags and surges in voltage by using the batteries' inverters to manage so-called VAR, or reactive power, he said.
Having lots of localized storage could also help manage the dips and jumps that come from lots of rooftop solar panels when clouds pass overhead, or help manage plug-in electric vehicles as they arrive in neighborhoods, he said (see Will Solar Crash the Smart Grid?)
Still, large-scale energy storage is better understood by utilities, he said. Maybe that's why they make up most of the projects that won a piece of DOE's $185 million for storage demonstrations last month.
Those grants include $21.8 million for Duke Energy to build a 20-megawatt storage system for its Notrees wind farm in west Texas, as well as Southern California Edison's plan to contract with A123 to build an 8-megawatt battery to store power from wind turbines in California's Tehachapi Mountains (see SoCal Edison Wants A123's Biggest Grid Battery Ever).
Flow batteries - which share some characteristics with fuel cells – got a boost in the form of $14 million to Primus Power to build a 25-megawatt flow battery farm for California's Modesto Irrigation District, as well as a $7.3 million grant for Premium Power to build six 500-kilowatt flow batteries for the Sacramento Municipal Utility District in California and National Grid in New England (see Grid Energy Storage: Big Market, Tough to Tackle).
On the distributed storage technology development side, Berkeley, Calif.-based Seeo got $6.2 million to develop its solid-state battery technology in a 25-kilowatt form for grid storage (see Startup Seeo Raises $8.6M, CFX Snags $5M).
Three projects using compressed air to store energy also got funding, including a $29.6 million grant for New York State Electric & Gas Corp. to build a 150-megawatt storage system in Watkins Glen, N.Y., and a $25 million grant to Pacific Gas & Electric to build a compressed air system near Bakersfield, Calif. (see Batteries Edge Out Compressed Air in Latest DOE Grants).
Roberts estimated that the United States will need to add about 80 gigawatts - that's 1,000 megawatts - to the 22 gigawatts of already existing energy storage by 2030, leaving a lot of room for multiple technologies to take the field.