Californian startup Voya Energy announced a $35 million funding round in August 2026 for generators that use prepared aluminum scrap, air and water to produce electricity without combustion. Its immediate opportunity includes replacing diesel backup equipment in data centers, where exhaust, noise and permitting can be real obstacles. The company also describes a larger market for firm power at grid-constrained sites, including 24-hour systems. The electrochemistry is established, but delivering competitive electricity requires a supply chain of materials that the generator specifications do not describe.
An aluminum-air cell consumes aluminum. It does not accept electricity through a charging cable and returns to its original chemical state. Aluminum reacts with oxygen and water, producing electrical energy and aluminum hydroxide, sometimes called aluminum trihydrate. The generator needs more metal when the fuel is used up, and the hydroxide must be collected, transported and sold to another market or further processed. Aluminum brought into a data center already contains a substantial amount of electricity previously used to convert aluminum compounds into metal. That upstream energy belongs to the evaluation.
I found the same supply chain issues when I examined Wright Electric’s aluminum and air aircraft proposal in 2021. The prepared aluminum would have needed to be delivered to airports, followed by collection and processing of the spent material. Data centers avoid aircraft weight limitations, while maintaining the need for ready fuel deliveries and industrial handling of reaction products.
The operational schedule determines the size of that problem. Voya’s August announcement emphasizes the replacement of diesel while also outlining larger, continuously available power facilities. To test the broader proposition, I calculated the materials needed for a hypothetical 100 MW data center continuously powered by air and aluminum generation. Using the company’s reported 57% conversion efficiency and the theoretical electrochemical energy of aluminum, the system consumes approximately 520 metric tons of metal each day and produces about 1,500 metric tons of aluminum hydroxide. This represents approximately 190,000 tonnes of incoming metal and 550,000 tonnes of outgoing material each year. The additional byproduct mass comes from the oxygen and water incorporated in the reaction. These are scenario quantities, not operations measured at a Voya site.
An intermittent backup generator could consume orders of magnitude less aluminum annually than the continuous 100 MW case, changing the economics of deliveries and waste management. Voya’s interest in low-quality contaminated scrap is worth examining, as some metal streams are difficult to sort into high-quality recycled products. However, scrap metal does not automatically lose its value because it is contaminated. Recycling aluminum into new metal products uses approximately 95% less energy than manufacturing primary metal, and improving scrap recovery is itself a major industrial decarbonization opportunity. Purchasing that scrap as expendable fuel can compete with other recovery routes as their technology and economics improve.
Voya initially hopes to sell aluminum hydroxide and proposes metal regeneration as a longer-term option. Those are different uses of the spent material. A 2026 life cycle assessment modeled an electric-to-electric round-trip efficiency of 29% to 35% for aluminum-air storage pathways involving regeneration. That finding is not a test result for the Voya team, but it indicates how much additional electricity and processing might be needed to close the material loop. A company that sells hydroxide cannot assume that it will recover that same material as fuel without purchasing it again.
Voya’s published metals price target leaves limited room for other costs. In a 2025 California Energy Commission filing, the company listed targets below $0.30/kWh for delivered electricity and $0.50 per pound for metallic fuel. At a conversion efficiency of 57%, the latter implies around $0.24/kWh for aluminum alone, before fuel preparation, generator capital, transportation, waste management or financing. Salable hydroxide could provide compensation if purity, processing costs and buyers support it. The generation target remains a target, rather than a demonstrated commercial rate.
There may be worthwhile applications for compact, combustion-free backup power where diesel is difficult to afford and suitable scrap is readily available. Continuous power for large AI installations requires a much greater comparison with grid connections, generation and rechargeable batteries. The chemistry works, but the economics must account for every load of metal delivered, every load of waste disposed of, and electricity consumed upstream.
My TFIE Strategy Briefing assessment follows the aluminum process through the generator, potential recycling and regeneration routes, Voya’s cost targets, and the very different demands for back-up materials and continuous generation.
