Century Aluminum smelter restart advances with extended power deal

Century Aluminum

Century Aluminum smelter restart plans have gained critical momentum after the company secured long-term power for its Mt Holly plant in South Carolina. The renewed supply agreement with utility Santee Cooper gives Century Aluminum smelter restart efforts the stability they need to bring idled capacity back online. As a result, the move positions the Mt Holly site as a key pillar in US efforts to rebuild primary aluminum production and reduce import dependence.

Power deal anchors Mt Holly capacity recovery

Century Aluminum smelter restart economics depend heavily on predictable electricity costs at Mt Holly. The new agreement with Santee Cooper secures a stable power supply through 2031, giving the producer the visibility required to commit fresh capital. The company plans to invest $50mn to return the smelter to its full 229,000 t/yr operating capacity by 30 June 2026, subject to incentive support from county and state authorities.

This restart will add around 50,000 t/yr of primary aluminum output versus current levels at the site. Therefore, Century estimates that the incremental production will lift total US primary aluminum output by roughly 10pc. For downstream users in automotive, packaging and construction, the Century Aluminum smelter restart should marginally improve domestic supply security and reduce exposure to import disruptions.

Tariffs reshape trade flows but import reliance remains high

US trade policy has reshaped the backdrop for primary aluminum investment. Earlier decisions to impose a 50pc tariff on primary aluminum imports, particularly from Canada, have tightened traditional supply channels and encouraged new domestic projects. However, even with the Mt Holly expansion, the US remains structurally short of primary metal.

Recent figures underline the scale of the gap between consumption and domestic output. US producers delivered about 670,000 t of primary aluminum in 2024, while the country imported more than 2.2mn t of unwrought, unalloyed aluminum. As a result, buyers still lean heavily on overseas suppliers, leaving the market sensitive to tariff changes, trade disputes and logistics shocks. The Century Aluminum smelter restart is therefore best seen as an important but partial response to wider supply security concerns.

The Metalnomist Commentary

Mt Holly’s restart underlines how power pricing, industrial policy and trade measures now interact in primary aluminum. Long-term competitive electricity remains the decisive factor for keeping smelting viable in the US, even under high import tariffs. Unless more facilities can secure similar conditions, the country will continue to rely on foreign producers for most of its primary metal needs.