A soldier refuels his gas-guzzling MRAP armored truck in Afghanistan.

[UPDATED with Burke remarks on biofuels & other alternative energy] WASHINGTON: Budget crunch be damned, the Defense Department’s effort to get more energy-efficient is still in business, said the assistant secretary in charge. Even without the free-flowing supplemental funds and the flexibility of the “rapid equipping” initiatives that allowed for speedy spending at the height of Afghanistan and Iraq, the Pentagon is still trying to reduce its dependence on fossil fuels, for reasons both tactical and operational.

“We’ll always have the ‘y’all come and show us what you’ve got’ types of programs,” said Sharon Burke, assistant defense secretary for operational energy, when I cornered her after her formal remarks at the Center for Strategic and International Studies this afternoon. “We’re always going to be looking for new ideas and we have a number of programs that do that, including some that specifically aim at small business.” The Afghan war in particular has seen a host of small-scale innovations, such as portable, blanket-like solar panels that troops on long patrols can unfold to recharge electronics when conventional supply lines can’t reach them. (House Armed Services Committee Republicans have been deeply skeptical of military use of biofuels and alternative energy in general, but they’re all for technologies that immediately benefit troops on the ground).

At the same time, she added, big, traditional defense contractors have a major role to play in wringing efficiencies out of jet engines, ship turbines, ground vehicle diesels, and other heavy, fuel-hogging hardware. But that will only happen if the military’s acquisition system makes fuel efficiency a formal, mandatory requirement — a “Key Performance Parameter,” or KPP — on every program, something the Joint Staff began enforcing last year.

“If you want to run off, experiment, there’ll still be opportunities to do that,” Burke told me. “[But] it’s incumbent on us to incorporate it in how we do business — and that’s what my office has taken aim at, with some success.”

“We’re always looking for good ideas,” agreed the Joint Staff’s director of logistics (aka the “J-4”), Marine Lt. Gen. Robert Ruark. And the military is looking for improvements in two areas and for two different reasons. “[Anything that] improves our operational availability, combat effectiveness, we’re always receptive to that,” the Afghanistan veteran told me after the CSIS event.

On the tactical level, a patrol that can recharge batteries in the field or an aircraft that can burn fuel more efficiently can stay on mission longer and go farther before returning to base. On a strategic and budgetary level, anything that reduces the Defense Department’s immense fuel consumption saves it big money. “There’s probably solutions out there that can present — despite fiscal austerity — a return on investment,” Ruark went on. Paying a near-term price for long-term savings is a hard case to make in this fiscal environment, and Ruark said he’d “defer to the comptrollers” on the tradeoffs, “but,” he said, “in some cases they will take a good look at return on investment.”

It’s crucial to understand that the Pentagon is waging a two-front war here: It wants energy efficiency to free combat forces from vulnerable supply lines and to reduce its overall operating costs. Some specific innovations may help with both goals — a more efficient engine both gives a vehicle a longer range and reduces cost per mile — but they remain two distinct criteria that, often, affect two different sets of companies. Small, innovative, fast-moving companies, including those outside the traditional defense sector, are the most capable of coming up with easily fielded innovations that help troops on the ground right now. But it takes big defense firms and their legions of subcontractors to reap savings from big programs.

“For us, it’s two things, it’s the volume of fuel use and the criticality,” Burke told me. “Even though a combat outpost in a remote area in Afghanistan doesn’t use a lot of fuel, they’re very hard to resupply and their ability to operate hinges on consistency of supply.” (Some readers will remember the infamous $400 a gallon “fully burdened cost of fuel” for the most isolated parts of the Afghan theater). For the troops at the outpost and those who have to brave the roads more or less frequently to resupply them, fuel efficiency isn’t economics; it’s a matter of life and death. Burke even began her remarks by reading from Mark Bowden’s famous 2011 article about the isolated and poorly supplied outpost overrun at Wanat.

“The solar panels for the security camera that’s on the perimeter on one of those combat outposts are really important, even though it’s not going to save you a lot of energy,” Burke continued. “But if you’re going to put a new engine on a C-130 or C-17 aircraft, a big cargo aircraft,” even if you just gain a few percentage points of fuel efficiency, she said, “that’s going to be a huge amount of fuel,” with major impacts both on the budget and on the speed of theater-level operations.

For those big-platform, big-program savings, Burke emphatically emphasized more efficient use of fossil fuels, not biofuel or other alternative energy. Even the natural gas boom in the US doesn’t directly affect military operations, she said, except to the extent that gas-to-liquid processes can affordably turn natural gas into jet fuel: Neither compressed natural gas nor ultra-cold liquefied natural gas is a good idea on the battlefield. She also took care to throw, if not cold water, than at least a little coolant on the idea of biofuels. Above all, fuel has to be available in as close as possible to where our forces operate, not shipped over long supply lines from the US itself.

“The No. 1 requirement is we need fuel to be available where we need it,” Burke told reporters. While biofuels, natural gas, and other alternatives are easily available in the US, to date only petroleum has a world-wide distribution system. That’s why the military has focused on making its existing engines able to run on alternative fuels as well as conventional ones, rather than put in the massive investment to move away from conventional fuels altogether.

Currently, Burke said, “we use jet fuel for everything,” from Army trucks to, well, jets. “Biofuels have to get cost-competitive. We’re ready to buy them if they’re cost-competitive. We’ve already tested and certified most defense systems on those fuels.”

From alternative fuel to more efficient jets, however, all these efforts have to continue despite tightening budgets, Burke told the audience at CSIS. “The Department’s at a grand reckoning moment,” she said. Sequestration will hit investments in energy efficiency, just as it punishes all forms of military modernization, she acknowledged, but “it’s not about what you’re going to have to take off the table to comply with sequestration: It’s about how you do what you are doing, and is it taking energy into account?”

Updated 9:35 am Tuesday with Burke remarks about biofuels and other alternative fuels.