The U.S. Navy is moving ahead with plans to fuel its ships with a diesel/biofuel blend, even though oil prices have dropped significantly since it first announced the plan.

Three years ago, the Navy won subsidies to help three companies build biofuel refineries to supply warships.

It also weathered criticism from Congressional Republicans about the high costs of alternative fuel.

DON'T MISS: Big Ships To Use Biofuels To Cut Emissions, Spill Risks--Eventually (Apr 2012)

Since then, oil prices have dropped about 70 percent--but the Navy's "Great Green Fleet" is ready to sail.

Cutting oil consumption still has strategic as well as environmental benefits, Navy Secretary Roy Mabus told Reuters as a Navy task force was set to refill its tanks with biofuels.

"It gives us an edge tactically, it gives us an edge strategically," Mabus said, claiming a focus on efficiency prevents fuel from "being used as a weapon against us."

Aircraft carrier USS John C. Stennis [Image: U.S. Navy via Flickr]

Aircraft carrier USS John C. Stennis [Image: U.S. Navy via Flickr]

Non-nuclear ships require a long and complex supply chain to ensure access to fuel wherever they happen to be in the world. Decreasing fuel consumption makes the Navy less vulnerable to logistical issues.

Rabus said the Navy has already cut its oil consumption by 15 percent since he took over in 2009, while the Marine Corps--its sister service--has cut oil use by 60 percent.

Referencing the Great White Fleet sent around the world by President Theodore Roosevelt to demonstrate American strength, the Great Green Fleet is an aircraft-carrier task group led by the nuclear-powered USS John C. Stennis, with escort ships fueled on a blend of 90 percent diesel and 10 percent biofuel.

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California-based AltAir fuels has a contract to supply 77 million gallons of the fuel--which is refined from beef tallow feedstock--between October 1, 2015, and September 30, 2016.

The Navy currently pays $2.05 per gallon, thanks to a subsidy of 15 cents per gallon from the Commodity Credit Corp.--a government-owned entity that supports farm products.

That's significantly lower than the $424 per gallon the Navy previously paid for 20,055 gallons of algae-based biofuel, or the $27 per gallon it paid for 450,000 gallons of a different biofuel.

Guided-missile destroyer USS Bulkeley refuels at sea [Image: U.S. Navy via Flickr]

Guided-missile destroyer USS Bulkeley refuels at sea [Image: U.S. Navy via Flickr]

But while it needs fuel to be cheap, the Navy also needs the amount available to increase.

It was previously awarded $210 million to fund three refineries to make biofuel from woody biomass, municipal waste, and used cooking grease and oil. The U.S. Department of Agriculture is providing an additional $161 million in crop supports.

MORE: New Jet Engine Designs Could Let Military Save 25 Percent Of Fuel Burned (Aug 2015)

These refineries are expected to start production this year, but won't reach full capacity until 2017.

In addition to U.S. producers, the Navy may buy from Italy and Chile once companies in those countries ramp up production, Navy Secretary Mabus said.

The Department of Defense uses about 14 million gallons of fuel per day, with the Navy responsible for about a quarter of that, according to the Defense Logistics Agency.

[hat tip: Brian Henderson]


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