The founder betting that the future of metal starts in the sea
Alex Grant spends his days thinking about a metal most people never notice. Magnesium is light, strong, and everywhere - in laptop shells, car parts, drone frames, helicopter gearboxes. It is also a metal the United States barely produces anymore. Grant, the co-founder and CEO of Magrathea, wants to change that from a warehouse in Oakland, California.
Magrathea's pitch is deceptively simple. Take magnesium chloride - a salt abundant in seawater and brine - and run electricity through it to split out pure magnesium metal. The chemistry is more than a century old. What Grant's team has done is rebuild it for the present. "We really modernized it and brought it into the 21st century," he told MIT Technology Review, describing an electrolyzer that runs at roughly 700 degrees Celsius and, deliberately, about 100 degrees hotter than it strictly needs to be. That extra heat is not waste. It is reused to dry the salt, and the design lets the plant pull power when renewable electricity is cheap and plentiful.
The result, according to an independent life cycle assessment completed in early 2025, is magnesium that can approach net-zero emissions. A byproduct of the process, magnesium oxide, can even absorb carbon dioxide from the air. For a heavy industry usually associated with smoke and coal, that is an unusual claim - and it is the claim Magrathea's entire business rests on.
We really modernized it and brought it into the 21st century.Alex Grant, on Magrathea's electrolyzer
From lithium to magnesium
Grant did not arrive at magnesium by accident. He trained as a chemical engineer, earning a bachelor's degree in chemical engineering and philosophy from McGill University and a master's in chemical engineering from Northwestern. Before Magrathea, he worked at Minviro, where he built environmental impact models for battery supply chains - including, by his account, the first embodied-carbon assessment for Tesla batteries. He then co-founded Lilac Solutions, one of the more talked-about names in lithium extraction.
The through-line is metals that matter for the energy transition, and a refusal to accept that making them has to be dirty. His LinkedIn handle - "biglithium" - is a small joke that carries a whole career inside it. When he left lithium for magnesium, he was not switching interests so much as following the same conviction into a harder problem.
That conviction has roots. Grant grew up in rural Canada, where hiking, fishing, and collecting animals gave him an early attachment to the natural world. The environmental instinct came first; the chemical engineering came later, as a way to act on it at industrial scale.
A climate company that became a defense company
Grant founded Magrathea in 2022 in San Francisco with a straightforward climate thesis: make a critical metal without the emissions and without tearing up mountains. Then the world intervened. He launched the company's first fundraise in March 2022, weeks after Russia invaded Ukraine. Magnesium, it turned out, is not just an EV material. It goes into Black Hawk helicopters, fighter jets, and AI-powered drones. As supply tightened and the US and its NATO allies scrambled, a green-metal startup suddenly looked like a national-security asset.
About a year later, Magrathea secured a Defense Production Act Title III partnership with the US Department of Defense - a roughly $28 million commitment to help develop the technology and shore up the American defense industrial base. Combined with around $12 million in private funding, it gave a company of fewer than 20 people the runway to attempt something incumbents had left for dead.
A viable technology solution in the short term with a proven end market and robust economics.Alex Grant, on what makes hard tech work
That framing is telling. Grant is a climate founder, but he talks like an operator. He has said publicly that the recipe for scaling hard technology is a workable solution in the near term, matched to a market that already exists and economics that hold up. It is a pragmatic creed, and it is part of why a small team has been able to move faster than much larger corporations.
Building the plant
Ambition, in this business, eventually has to become steel and concrete. Magrathea has been building a demonstration plant in Utah, aiming for around 1,000 tons of magnesium a year by 2027, with a longer-term vision of commercial plants producing on the order of 50,000 tons annually. The company currently sources its magnesium chloride from food giant Cargill, and in early 2025 announced a pre-purchase agreement with a major automaker - a signal that the metal has real buyers waiting.
The name Magrathea is a nod to Douglas Adams's The Hitchhiker's Guide to the Galaxy, where Magrathea is the legendary planet whose inhabitants build other planets to order. It is a fitting flag for a company that treats manufacturing as a creative act rather than a dirty necessity.
Grant is also vocal about policy. He has argued that tariffs alone will not rebuild American industry, and that the federal government needs to put real capital - grants and loan guarantees - behind the leap from pilot to commercial scale. It is the argument of someone who has looked closely at why US magnesium production collapsed in the first place, and does not want to watch the next generation of factories die between a working prototype and a financeable plant.
Whether Magrathea reaches its numbers is still an open question. Primary metals is a brutal industry, and plenty of promising chemistry has stalled on the way to scale. But Grant has assembled the rare combination that makes people pay attention: a modern take on old chemistry, a market that spans EVs and the Pentagon, and a founder who has already built once in an adjacent metal. He is not promising to reinvent magnesium. He is trying to make it here, cleanly, and at a price the market will pay - and for now, that is enough to keep the checks coming.