Global Trade
October 6, 2025
Mt. Holly smelter secures power deal
Written by Stephanie Ritenbaugh
Century Aluminum Co. has made another step toward restarting idle capacity at its Mt. Holly smelter outside of Charleston, S.C.
The Chicago-based producer said Monday it signed an extension of its power agreement with South Carolina Public Service Authority (Santee Cooper) to secure energy for the smelter through 2031.
Century Aluminum plans to invest $50 million to restart idle capacity, boosting production by 50,000 metric tons. The company said the plan will increase overall US aluminum output by 10%.
The smelter is currently operating at 75% of its 230,000 metric ton nameplate capacity. It is expected to reach full production by early summer 2026, a level not achieved since 2015, the company noted.
Affordable energy was a major factor in the full closure or idling of more than 30 smelters in the past 45 years – most recently, the idling of Century’s Hawesville, Ky., smelter, as well as curtailments at Mt. Holly and the shuttering of Magnitude 7’s New Madrid, Mo., plant.
Now, those facilities are competing with other large-scale electricity consumers, namely data centers supporting AI, which are rapidly straining grid capacity in several U.S. regions.
Century first announced the restart in August, crediting President Trump’s Section 232 tariffs on imported aluminum – which Trump doubled from 25% to 50% in June.
The final details of the restart will be subject to the confirmation of economic incentives provided by Berkeley County and the state of South Carolina, Century Aluminum said.
The Mt. Holly smelter, built in 1980, was the last primary aluminum smelter built in the United States.
