SK Innovation Co., Korea’s top refiner, broke ground on its second plant Monday to produce batteries for electric vehicles, upping the ante for its fledgling green energy business as a next-generation revenue source.

Located in Seosan, South Chungcheong Province, the facilities will start manufacturing 200-megawatt-hour batteries early next year and 300-MWh batteries by the end of 2012, SK Innovation said in a statement. A megawatt hour is the amount of power used if 1 million watts are used for an hour.

Combined with its first plant in Daejeon, which produces 100-MWh batteries, the energy firm will secure a production capacity of 600 MWh, sufficient to supply more than 30,000 high-speed electric cars each year.

“The factory will boost SK Innovation’s battery business that has gained recognition in the world market,’” SK Group Vice Chairman Chey Jae-won said at the groundbreaking ceremony.

“It will also contribute to invigorating the local economy by creating jobs in the region and make positive impacts in cooperation with battery components suppliers.”

SK Innovation said it plans to provide batteries to Korea’s top two automakers, Hyundai Motor Co. and Kia Motors Corp., along with German-based Daimler AG’s two units, Mercedes-AMG GmbH and Mitsubishi Fuso.

The refiner has been pursuing next-generation energy projects involving clean coal, biofuel, hydrogen energy, smart grid and others as future growth engines over the last few years.

It also produces lithium-ion battery separators, a key element in EV batteries. Its sixth and seventh LiBS plants are under construction, and are due to be completed next year.

By Shin Hyon-hee (heeshin@heraldcorp.com)