Hillside Aluminium Smelter Future Hinges on South32 Eskom Power Deal

Hillside Aluminium

Hillside aluminium smelter operations beyond 2031 will depend on a new long-term power agreement between South32 and South African utility Eskom. The companies are negotiating a replacement contract for the KwaZulu-Natal smelter before its current discounted electricity supply arrangement expires.

The Hillside aluminium smelter is one of South Africa’s most important energy-intensive industrial assets. Securing competitively priced power is essential because aluminium smelting depends on stable, large-scale and affordable electricity.

South32 and Eskom have created a working group to explore ways to bring competitively priced renewable energy into South Africa’s national grid. The goal is to support Hillside’s future power needs while also benefiting Eskom’s wider customer base.

The talks come shortly after South32 moved its Mozal aluminium smelter in Mozambique into care and maintenance after failing to secure a new electricity supply agreement. That decision highlights the strategic risk facing smelters when power contracts expire without a commercially viable replacement.

Power Security Becomes the Main Aluminium Constraint

Electricity is the defining cost factor for primary aluminium. Smelters need continuous power, and even modest changes in tariffs can determine whether production remains competitive.

The Hillside aluminium smelter currently benefits from a discounted power contract that runs until 2031. A new agreement would secure the plant’s operating future beyond that date and reduce uncertainty for workers, suppliers and downstream customers.

South32’s experience at Mozal shows what is at stake. The Mozambican smelter was moved into care and maintenance after its electricity contract expired at the end of March and no new agreement was reached.

That outcome gives urgency to the Hillside negotiations. Without a competitive long-term power solution, South32 could face difficult decisions about one of its key southern African aluminium assets.

For Eskom, the talks also carry wider industrial policy significance. South Africa needs to preserve energy-intensive manufacturing while managing grid constraints, decarbonisation pressure and the transition toward cleaner power.

Renewable Power Could Support Low-Carbon Aluminium

The working group’s focus on renewable energy shows how aluminium supply is becoming tied to decarbonisation. Buyers increasingly want lower-carbon aluminium, especially in automotive, packaging, construction and industrial applications.

A renewable-linked power solution could improve Hillside’s long-term competitiveness. It would help South32 reduce emissions exposure while keeping the smelter connected to South Africa’s industrial base.

However, the challenge is execution. Renewable power must be competitively priced, reliable and integrated into the national grid in a way that supports continuous smelter operations.

The agreement could also set a precedent for other energy-intensive industries in South Africa. If Eskom and South32 can structure a viable low-carbon power model, it may help attract or retain industrial investment in metals, chemicals and manufacturing.

For the aluminium market, the message is clear. Future smelting capacity will depend less on ore or alumina access alone and more on long-term power security, grid reliability and carbon intensity.

The Metalnomist Commentary

The Hillside power talks show that aluminium competitiveness is now an energy strategy question. South32 and Eskom must prove that South Africa can keep heavy industry alive while moving toward lower-carbon electricity.