Jamalco unplugs from grid, power turbine set to save up to US$28m a year
Century Aluminum’s Jamalco alumina refinery in Clarendon began operating a new TG4 power turbine in early August, allowing self-generated electricity and reducing reliance on Jamaica’s grid. CEO Jesse Gary said it could save about US$20 per tonne, or up to US$28m/year. Century reported Q2 adjusted EBITDA US$326.9m and net income US$249.3m.
How this was made
The 30-second read
Why it matters
The TG4 turbine is positioned as a structural cost improvement by enabling fully self-generated power, with quantified savings and a 2026 ramp, while other operational issues (bauxite quality) may affect how quickly output and margins benefit.
Market read
A concrete operational upgrade with quantified unit-cost savings and a defined phase-in window can change traders’ margin and earnings trajectory assumptions for CENX.
What to watch
The article notes the bauxite quality problem will take “another couple of quarters” to implement the revised mining plan, which could delay the full benefit of the power upgrade.
Background
Century’s Jamalco alumina refinery in Clarendon previously relied on the national grid for electricity, which proved unreliable during Hurricane Melissa in late 2025.
Ticker impact
Century Aluminum says its Jamalco TG4 turbine now lets the refinery generate all electricity, cutting reliance on the Jamaican grid and improving cost structure.
Moderate positive bias for CENX as the cost-savings ramp and capacity utilization improve, though magnitude depends on execution and bauxite quality recovery.
The article provides quantified savings per tonne and an annual capacity-based savings estimate, plus timing (phase-in remainder of 2026) and links the upgrade to prior grid instability from Hurricane Melissa.
Market effects
Highlights how power reliability and energy costs can materially affect aluminum/alumina producers’ unit costs, especially in grid-constrained geographies.
Jamaica grid instability is cited as a driver of prior costs, implying improved operational resilience for the Clarendon alumina complex.
Energy-cost optimization and capacity ramp-up can influence global alumina supply economics, but the article is company-specific rather than a broad market shock.
Counterpoint
Savings may be partially offset by ongoing bauxite quality issues and raw-material headwinds, limiting near-term margin expansion despite lower power costs.
Key entities
- public_companyCentury Aluminum Company
US-listed producer that brought TG4 online at its Jamalco refinery and reported earnings with quantified cost-savings expectations.
- operating_assetJamalco (Clarendon alumina refinery)
Alumina joint venture where the TG4 turbine enables islanded electricity generation and reduces grid purchases.
- projectTG4 turbine
New power-generation turbine enabling Jamalco to generate all electricity and reduce reliance on the Jamaican grid.
- eventHurricane Melissa
Category 5 storm that exposed grid vulnerability and drove hurricane-related costs in 1Q26.
