Sen. John McCain (R-Ariz.) criticized the Navy’s work to help develop renewable energy yesterday, saying the service cannot afford such efforts as it faces sizable budget cuts.

“Using defense dollars to subsidize new energy technologies is not the Navy’s responsibility, nor is it sufficiently related to the service’s core mission to justify such expenditures,” McCain said during a congressional hearing yesterday, spurring Navy Secretary Ray Mabus and other senators yesterday to defend the sea service.

Mabus has called for the Navy and Marine Corps to receive half of their energy from non-fossil fuels by 2020. McCain lamented that the Navy will need 330 million gallons a year of alternative fuels to meet that goal, noting that in 2008 the service paid $424 per gallon for 20,000 gallons of biodiesel made from algae.

During a Senate Armed Services Committee (SASC) hearing, McCain, its ranking member, suggested the Navy should not be dedicating $170 million as part of a $510 million effort with the departments of Energy and Agriculture to create a commercially viable biofuel market amid sizable defense budget cuts.

“I believe it’s the Energy Department who should be doing that, and obviously I will seek to act on amendments on the floor to try to prevent this kind of waste of the taxpayers’ dollars, where they’ve paid $424 a gallon for algae fuels,” McCain said. “I don’t think we can afford it.”

Mabus said the Navy is acting in line with the Defense Production Act, which dates back to the 1950s. The law “says that if there is an industry that (the) Defense (Department) needs but does not exist in the United States, that Defense not only can but should invest in that industry,” the Navy secretary said. “Energy is specifically mentioned in the Defense Production Act as something that Defense should look at.”

He acknowledged the “small test amounts” of biofuels that Navy bought in the past were costly. Yet he said the cost has been cut in half in the past two years for the small test amounts the service has been buying.

“We are convinced that as the military brings a market here that the cost of biofuels will be competitive with existing fossil fuels,” Mabus said.

He further argued the Navy “cannot afford not to do this.”

“We can’t afford to be dependent on foreign sources of fuel,” he said. “We cannot afford to be dependent on a worldwide commodity that has the price spikes and the price shocks that we have…The only place I have to go to get money when the price of fuel goes up is out of operations accounts.”

SASC Chairman Carl Levin (D-Mich.), for his part, told Mabus he’s “going to find a lot of support for the energy initiatives that you’ve taken on this committee.”

Levin rejected the argument that such energy efforts should not be pursued by the Navy because they cost more in the near term.

“Well, of course they do, and that’s why we can’t just rely on the private sector to produce them because the private sector has a different goal than our military does and our government does,” Levin said. “Their goal, legitimately, is profit….Short-term profit is not always the same as planning for our nation’s security.”

Sen. Mark Begich (D-Alaska) and Kay Hagan (D-N.C.) also defended the Navy’s work with alternative and renewable energy.

Mabus said Navy and Marine Corps efforts to reduce dependence on foreign oil and use energy more efficiently have already “made us better warfighters.” For example, a Marine patrol in Afghanistan that used solar blankets to recharge electrical items dropped 700 pounds of batteries from their packs and “decreased the need for risky resupply missions,” he said.