Is Seawater the Next Big Fuel Source?


Jets can fly over the sea, but soon the sea may be able to help jets fly.     Photo: United States Marine Corps/Flickr



To create the fuel, Wilhauer's team extracted carbon dioxide and hydrogen bound in the water and recombined those gases in a catalyst reactor to produce the liquid fuel. The process can be applied to different metals to engender methanol, liquid natural gas, gasoline, diesel, or jet fuel. "Because it's a synthetic process, you can tailor it to whatever fuel you need," Wilhauer notes.

If that sounds like the jackpot, it could be—in a perfect world. Like water that's pumped uphill using electricity and later released to generate electricity, the CO2 and hydrogen extracted from the sea end up back in the water where they started. "You have to put more energy in to get the fuel than you get out of the fuel when you use it," says Brentan Alexander, founder of the Stanford Energy Club and Senior Mechanical Engineer at Wrightspeed. "So it's still net-energy negative. When you start applying that towards generating fuel on a larger scale in the United States, you're going to run into a really hard wall to make that cost-effective, because natural gas is cheap."

But for the Navy, which moves 1.2 billion gallons of fuel annually, it makes perfect sense. "Our aircraft carriers are nuclear powered, but we still have to get fuel out to there to fly the airplanes," says Rear Admiral Kevin Slates, who works on the Navy's environmental and energy programs. Barges must frequently haul resupply fuel across oceans to aircraft carriers, and other ships protect those barges, all of which require their own fuel. "This would allow us to produce fuel at the point of consumption and basically untether that ship," says Rear Admiral Slates. It also eliminates risk of potential fuel spills during transport. "The delivered cost of fuel to our fleet at sea is obviously more expensive than what we're paying at a pump. Then [seawater fuel] becomes cost-competitive much quicker than for, say, commercial automobiles."


"It all hinges on whether it can scale up to produce the quantities that we need," says Rear Admiral Slates, which could take ten to 15 years. "It's clearly a game-changing, innovative technology that we're really interested in."

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