The Santee Cooper Board of Directors voted Friday to authorize the retirement of six electric generating units at its two oldest stations, the Grainger plant in Conway and the Jefferies plant in Moncks Corner.
This marks Santee Cooper's first unit retirements since the state-owned utility first generated power 70 years ago.
Santee Cooper blames the closures on costs of complying with new environmental regulations.
Layoffs are not expected. Santee Cooper plans to relocate employees that are affected to other positions.
The Grainger station has been idle since spring as Santee Cooper evaluated potential impacts of the U.S. Environmental Protection Agency's new Mercury and Air Toxics Standard (MATS) for air emissions, issued last December.
There is no official date set for closing the plants.