Usually when the Pentagon's far-out research branch thinks about energy, it comes up with ideas like, oh, putting miniature nuclear reactors on forward operating bases. But on Friday, Darpa buttoned its collar up tightly and asked its industry partners to come up with innovative ways to conserve energy in warzones.

The Deployed Energy Storage program calls for "Flexible / robust energy storage systems," to cut down on the amount of fuel that the military burns through to operate out at its remote wartime bases. The need is obvious. Not only is fuel expensive, transportation convoys to get fuel to the bases are frequent targets for insurgents.

Two things Darpa isn't trying to do with this effort: increase fuel efficiency or generate power. It wants to come up with better, durable ways of storing energy, so that the energy generated on bases that use even alternative energy sources like wind or solar doesn't immediately go into electricity. And when it comes to those energy sources, whatever Darpa's going to fund has to survive "millisecond to multiple day outages" associated with, say, the sun setting or inclement weather preventing power generation.

The system has to be durable enough that it can power a base for days when primary power sources go off-line or are unavailable. And it's got to store a lot of power for sustained periods of time "The system at full charge will be capable of providing uninterrupted power to a 150 [kilowatt] average load for 9 days with 90% reduction and 30 days with a 30% reduction in available generated power from an appropriately sized renewable power generation plant," Darpa says. The ultimate goal: 100 kilowatts of power, continuously for 30 days, using renewable energy sources.

If you've got "evolutionary" ideas for meeting that target, you'll be considered "unresponsive to this announcement," Darpa intones. Set your goals high.

Still, it's a decidedly more conventional idea than one envisioned in Darpa's 2012 budget request to Congress. A research pilot program called the "Small Rugged Reactor Technologies" effort proposed building "nuclear-fuel reactor[s]" on small warzone bases to make them "self-sufficient" in terms of energy generation.

And even that was further down to earth than a 2009 proposal to manipulate lightning.

Even so, Darpa's got a lot of recent experience to draw on if it wants to solicit troops' views. The 3rd Battalion, 5th Marine Regiment recently returned home from a grueling tour in Sangin, Afghanistan. During their time there, one of their companies brought photovoltaic cells and cut their energy use down by 90 percent. They could probably tell Darpa a lot about what they used to store their energy, as well as what they would have liked to use.

Photo: U.S. Air Force

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