WASHINGTON — Navy Secretary Ray Mabus said Wednesday that reducing the Navy’s dependence on foreign fuel sources, one of the top vulnerabilities the military faces, remains a strategic priority.

“Seeking out some viable energy options isn’t a fad. It isn’t the flavor of the day. We’re doing it because we have to be a more effective fighting force,” Mabus told attendees at the Washington Energy Summit. “It makes us better war fighters.”

Mabus highlighted the strategical and tactical need for the Navy to turn to the biofuel market in anticipation that the current annual average $107- price of a barrel of oil is a sign that spikes are a lasting trend.

When Mabus first announced the Navy’s energy goals in October of 2009, the price of a barrel of oil was $76. For every $1 increase in the price of a barrel of oil, the U.S. military faces $31 million in additional fuel costs.

This is an unacceptable level of budget uncertainty, Mabus said, emphasizing that unplanned price spikes result in fewer flying hours and less training.

Mabus said that the use of alternative fuel sources will take the Navy a long way. But the Navy faces the challenge of producing an alternative fuel source that will work with existing engines.

“That’s the barrier – getting from the good idea in the lab and small test batches to commercially viable fuels,” Mabus said.

The tactical reasons for turning to alternative fuel sources are arguably more compelling. Mabus pointed to the 3rd Battalion, 5th Marines ability to cut fossil fuel use and logistical supply requirements by 25 percent at main operating bases and up to 90 percent at combat outposts by relying on alternative energy sources. These efforts eliminated their need to be re-supplied every two to three days.

The Navy is most vulnerable during refueling. For every 50 convoys of fuel that the Navy brings to Afghanistan, there is one Marine killed or wounded. “It’s way too high a price to pay for fuel,” Mabus said.