When Captain Jim Goudreau describes the U.S. Navy's goal of cutting in half its use of fossil fuels by 2020, he uses words like “daunting” and “challenging.” Goudreau is director of the Navy’s Energy Coordination Office. And another word he uses to describe the goal is “necessary.” He said the Navy needs to end its heavy dependence on petroleum.
"And sometimes we buy it from counties that may or may not have the same interests as us. But we need the fuel to operate,” he said, adding that it would be “prudent” to develop a domestic source that gives the Navy assured mobility.
“We must always have something that allows us to go forth and do our mission as tasked by the nation," said Goudreau.
The Navy ships and aircraft in San Diego still run predominantly on petroleum. But that may change soon. In fact, though Goudreau works at the Pentagon, he said he was standing on a pier in San Diego last fall to see a Navy ship pull away under the power of biofuel. What’s more, one of the alternatives the Navy is testing is algae fuel, which San Diego scientists are working to develop.
Goudreau said the Navy's search for alternative fuels has shown that some are far from ideal. He said biodiesel can damage equipment and gum up filters. Another alternative, ethanol, has low energy density. Fill a ship's tank with that, he said, and it will go only half as far.
What the Navy needs are fuels that can literally take the place of petroleum. The Navy calls them drop-in fuels.
"The key for us is to get an operational fuel that will go straight into our aircraft and straight into our ships,” said Goudreau, “without having to change any of the engineering inside the ships, and without having to change any of the storage or distribution infrastructure. It's got to be a true drop-in fuel."
And this is where algae comes in.
Algae fuel is an alternative the Navy is testing. UC San Diego molecular biologist Steve Mayfield is a founder of Sapphire Energy, a San Diego-based company that is already producing algae fuel at its demonstration plant in New Mexico. Some of it has been converted for use as jet fuel. Mayfield now serves on the company's science advisory board. He said the Navy has a proud history of transitioning between energy sources.
"This is the group that took us from wind power to coal, from coal to petroleum, and from petroleum to nuclear power,” said Mayfield. “They just have a fantastic history of a can-do approach to... ‘Our adversaries have new technology and we've got to up the game.’ And they do."
Mayfield said algae makes an ideal drop-in fuel because it's basically the same as the petroleum we have pumped out of the ground.
"(Petroleum) was simply ancient algae that had been covered over by shallow seas and then was covered over by silt and dirt,” said Mayfield. “The algae’s proteins and carbohydrates degraded away, leaving the fat, which we call crude oil. So the algae we produce in ponds today makes the same stuff."
Mayfield said while the Navy's primary concern is national security it should also worry about global warming, since it would have to deal with the mess that is created by rising sea levels and refugees fleeing drought-stricken areas.
But if algae fuel is the same stuff as petroleum, why would it be any better for stopping global warming? Mayfield said when you use algae there's no net gain in greenhouse emissions in the atmosphere. That’s because when you grow algae it consumes the same carbon it produces when you burn its oil.
Some people wonder whether the Navy’s calculation would change if American production of shale oil increases to the point where the Navy could get enough oil from domestic sources? Naval Secretary Ray Mabus has said even if that happened, oil is still a world commodity and it's still subject to shortages and price shocks the US cannot control.
Despite the glowing reviews of a possible algae solution, the fuel is still in the testing phase and there’s not nearly enough out there to launch a thousand ships. Captain Goudreau said, for the Navy, cost will be an issue.
"We're not going to buy large quantities for normal operations until it's a cost-competitive product," he said.
Mayfield responded by saying that means the industry has to move beyond simply building demonstration plants and start building commercial facilities.
"And by going to that commercial size," he said, "you can demonstrate the reduction of costs you get from economies of scale."
