Fuel cells are not a renewable energy source, of course, although they can be tied to renewable energy. But even using fossil fuels their ability to produce electricity through an electrochemical process – instead of combustion – can make them flexible, relatively clean and efficient energy producers.

And quiet, too, the U.S. Navy’s Office of Naval Research points out, and you can imagine how that might be a big benefit to the military.

navy fuel cell
Supply convoy in Afghanistan, 2011 (image via U.S. Army)

The ONR, the scientific research arm of the Navy and Marine Corps, is talking up the new Solid-Oxide Fuel Cell Tactical Electrical Power Unit that uses technology developed through its programs. A 10-kilowatt unit was demonstrated at the Army’s Aberdeen Proving Ground in Maryland earlier this summer, and it used 44 percent less fuel than a similarly sized conventional generator, the ONR said.

“Fuel cells are real and are ready for transition to our warfighters,” Don Hoffman, a program officer in ONR’s Sea Warfare and Weapons Department, said in a statement. “We’re pushing forward to examine adapting this technology for use aboard ships as well.”

We’ve written frequently about the U.S. military’s deep interest in turning to more efficient energy sources for its front-line operations. This has led to initiatives like RENEWS – the Reusing Existing Natural Energy, Wind & Solar system – that enables the harvesting and utilization of wind and/or solar power and is intended to produce up to 300 watts of energy in silent, remote operations where the supply of power and fuel resupply is difficult or risk.

This, and the fuel cell development, flows from the Department of Defense’s Operational Energy Strategy to be less reliant on risky-to-transport fossil fuels. The sought-after payoff is quite tangible: “Using less fuel ultimately means fewer convoys and more lives saved,” John Pazik, director of ONR’s Ship Systems and Engineering Research Division, said.

Solid-oxide fuel cells are the same technology Bloom Energy uses (there’s a good animated primer on the Bloom site that shows how it works). Bloom Boxes are most frequently fed natural gas as the hydrogen source. The Navy has different needs:

A key component to the new system is a small reformer inside the unit that converts high-sulfur military fuels – such as JP-8 jet fuel – into a hydrogen-rich gas capable of use in the fuel cell. Previous systems required heavy maintenance to operate with such fuels. In addition to an easy-to-deploy modular and compact design, the new technology allows for near-silent operation. Instead of the roar of a diesel generator, the fuel cell unit’s cooling fan produces a sound similar to the quiet hum of a refrigerator or air conditioner.