AES Corp. (AES), the biggest operator of electricity-storage systems, is now seeking to sell batteries big enough to substitute for power plants.

The Advancion systems will cost from $10 million to $500 million, depending on size, and will be offered to utilities and renewable-energy developers in arrays as large as 500 megawatts, said Chris Shelton, president of Arlington, Virginia-based AES’s energy storage unit. The company has operated its own battery systems as large as 64 megawatts, enough to supply 51,000 average U.S. homes, in the U.S. and Chile for more than two years.

The batteries will store power when its cheap and abundant and then feed it to the grid during periods of high demand. They may replace so-called peaking plants that typically are fueled by natural gas and are costly to build and run because they sometimes operate only a few hours a year. The systems also can compensate for the intermittent output from wind and solar farms, according to a statement today.

“We’re competitive with power plants,” Shelton said in a telephone interview. “People are really seeing that this could be part of comprehensive future planning for the utility sector.”

Advancion systems, which can supply power for as long as four hours, will cost about $1,000 a kilowatt, compared to about $1,350 a kilowatt for a recently built gas peaker plant, he said.

AES owns a 64-megawatt battery system at the Laurel Mountain wind farm in West Virgina that “competes every day and wins” in the wholesale power market, he said.

Lithium Ion

The first Advancion systems will use lithium-ion batteries from LG Chem Ltd., the same technology used in laptop computers, smartphones and electric cars. Parker Hannifin Corp. is providing inverters and AES designed the control systems and software. AES intends to certify other battery suppliers at an Indianapolis test facility.

AES is offering the systems in Hawaii and California, where demand for wind and solar farms is increasing, and in regions served by PJM Interconnection LLC, the largest U.S. wholesale power market. It’s also pursuing sales in the U.K. and the Philippines.