Voya Energy raised $35 million in August 2026 to develop generators that produce electricity by reacting prepared scrap aluminum with air and water. The California startup sees an immediate opportunity in replacing diesel backup systems at data centres, where exhaust, noise and permitting can pose challenges. It also points to potential use at grid-constrained sites needing continuous power.
The technology consumes aluminum rather than recharging it. The reaction generates electricity and aluminum hydroxide, which must be collected and either sold or processed further. This means the system depends on deliveries of prepared metal and a plan for handling the resulting material. The aluminum also carries the energy used earlier to produce the metal, a factor that must be included in any broader assessment.
The scale of those logistics depends on how often the generators run. In a hypothetical calculation for a continuously powered 100 MW data centre, using Voya’s reported 57% conversion efficiency and aluminum’s theoretical electrochemical energy, the system would consume about 520 metric tons of aluminum daily and produce around 1,500 metric tons of aluminum hydroxide. That equates to approximately 190,000 tons of metal delivered and 550,000 tons of byproduct removed each year. These are scenario estimates, not results from an operating Voya installation.
A generator used only for occasional backup would require far less fuel than the continuous-power scenario. Voya has also highlighted low-grade, contaminated scrap as a possible input. However, contaminated aluminum is not necessarily without value: recycling aluminum into new metal products uses about 95% less energy than producing primary aluminum, so using scrap as fuel could compete with other recovery options.
Voya initially expects to sell the aluminum hydroxide and describes metal regeneration as a longer-term possibility. Those routes cannot be assumed to operate together without additional costs: material sold to a buyer would have to be recovered again if it were later used to make fuel. A 2026 lifecycle assessment modeled round-trip electricity efficiency of 29–35% for aluminum–air pathways involving regeneration. That assessment was not a test of Voya’s equipment, but it points to the energy and processing needed to close the material loop.
The company’s published cost targets also leave other expenses to account for. In a 2025 California Energy Commission submission, Voya listed targets of less than $0.30 per kilowatt-hour for delivered electricity and $0.50 per pound for aluminum fuel. At 57% conversion efficiency, the metal price alone would amount to about $0.24 per kilowatt-hour, before fuel preparation, generator costs, transport, byproduct handling or financing. Sales of aluminum hydroxide could offset some costs if its purity, processing requirements and market buyers make that viable. The electricity price remains a target, not a demonstrated commercial rate.
Aluminum–air generators may suit compact backup applications where diesel is difficult to permit and suitable scrap is available. Supplying large data centres continuously would require a broader comparison with grid connections, other generation and rechargeable batteries, while accounting for every shipment of fuel and removal of reaction products. TUESDAY:VEVENT? Nope." }
Sources: CleanTechnica.