Jamalco goes off-grid as new power turbine targets $28 million in annual alumina savings

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Jamalco has switched on a new power turbine at its Jamaican alumina refinery, allowing the plant to generate all its electricity independently of the national grid and potentially cut production costs by around USD 28 million a year. 

Jamalco has taken a major step towards reducing the cost of producing alumina after bringing a new power-generation turbine online at its refinery in Clarendon, Jamaica.

The turbine, known as TG4, allows the refinery to generate all of its own electricity, reducing its reliance on purchases from Jamaica's national grid. Century Aluminum, which owns a 55 per cent stake in the Jamalco joint venture, expects the change to deliver savings of around USD 20 per tonne of alumina.

With Jamalco capable of producing around 1.4 million tonnes of alumina a year, that works out to potential savings of approximately USD 28 million annually once the full benefit is realised. Century said the savings will be phased in over the remainder of 2026.

Jamalco becomes its own power source

The refinery can now operate independently of Jamaica's national grid, reducing its exposure to electricity costs as well as potential disruptions.

“TG4 allows us to run Jamalco on entirely self-generated energy, eliminating expensive and, as we learned last winter, sometimes unreliable purchases from the Jamaican grid,” said Jesse Gary, president and chief executive officer of Century Aluminum.

Gary described the refinery as being able to operate “as an island within the island”.

The move is particularly significant after Hurricane Melissa, which struck Jamaica as a Category 5 storm in October 2025 and caused prolonged instability across the national electricity grid.

Jamalco recorded USD 10.6 million in hurricane-related costs during the first quarter of 2026. Those exceptional charges had fallen to zero by the second quarter, indicating that much of the refinery's recovery from the storm had been completed.

The new self-generation capacity therefore gives Jamalco another layer of protection against potential grid-related disruptions.

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The timing is important as Jamalco reaches full capacity

Management said Jamalco reached full or near-full production capacity by the end of July, marking the first time in more than a decade that the refinery has reached that level.

That makes the potential USD 20-per-tonne energy saving particularly significant. Producing more alumina while reducing the amount spent on electricity could improve the refinery's overall cost structure as the benefits from TG4 build through 2026.

Century included the turbine in a broader USD 20 million to USD 30 million capital programme for Jamalco covering sustaining operations and new investments.

The company owns 55 per cent of the joint venture, while the Government of Jamaica, through Clarendon Alumina Production Limited, owns the remaining 45 per cent.

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Lower power costs, but bauxite quality remains a challenge

While Jamalco is making progress on the energy side, the refinery continues to face another challenge: bauxite quality.

The company has reported lower-quality bauxite from some of its mining areas. Management has introduced a revised mining plan to address the issue, although it expects the changes to take another couple of quarters to be fully implemented.

The broader raw-material challenge was previously estimated at around USD 10 million sequentially. That figure includes the bauxite-quality issue as well as higher costs for coke, pitch and caustic soda linked to the Middle East conflict and shipping disruptions through the Strait of Hormuz.

For Jamalco, therefore, the new turbine addresses one important part of the refinery's cost equation while the company continues working through raw-material and logistics pressures.

A stronger quarter for Century Aluminum

The Jamalco developments came during what Century described as a transformational second quarter.

The company's other major operating assets, including the Mt Holly smelter in South Carolina and the Grundartangi smelter in Iceland, also reached full or near-full capacity.

Century reported second-quarter adjusted EBITDA of USD 326.9 million, an increase of USD 95.5 million from the previous quarter. Net sales reached USD 752.1 million, while net income attributable to Century stood at USD 249.3 million, or USD 2.39 per diluted share.

For Jamalco, however, the immediate focus is much simpler: generating its own power could help the 1.4-million-tonne alumina refinery lower costs, improve energy security and operate with less dependence on the national electricity network.

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