The U.S. Navy on Wednesday launched its first carrier strike group powered partly by biofuel to conduct operations in the Pacific.
The "Great Green Fleet" warships powered by alternative energy is a milestone toward easing the military's reliance on foreign oil.
Most of the group's ships will run on a mix of 90 per cent petroleum and only 10 per cent biofuels, though that could change. The Navy originally aimed for the ratio to be 50/50.
Navy Secretary Ray Mabus and Agriculture Secretary Tom Vilsack kicked off the deployment in a ceremony at Naval Air Station North Island near San Diego, saying the use of biofuels would improve the Navy's operational flexibility while boosting the U.S. rural economy.
Vilsack called the Navy's "Green Fleet" a "tremendous opportunity" for the biofuel industry that will benefit farmers and create thousands of jobs.
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.
"In 2010, we were losing too many Marines in convoys carrying fossil fuels to outposts in Afghanistan, and the prohibitive cost of oil was requiring us to stop training at home in order to keep steaming abroad, a dangerous and unsustainable scenario," Mabus said in a statement.
The Defence Department uses 90 per cent of the energy consumed by the federal government, spending billions of dollars annually on petroleum fuels to support military operations.
The Navy plans to have its fleets powered by at least 50 percent biofuel by 2020 so that fuel can’t be strategically withheld by foreign suppliers in the event of a conflict. Reducing decencies on foreign oil is a national security strategy being undertaken by all branches of the US military.