November 30, 2011:
Despite strenuous efforts, the military has not been able to find renewable substitutes for the major consumers of fuel in the field. Large fuel cells are slow to arrive ready for use in a combat zone. The one bright spot has been two older technologies.
One is solar panels. A system weighing less than 10 kg (22 pounds) contains the foldable solar panel, batteries for storing power and adapters for recharging various civilian and military type batteries. For Special Forces patrols, and isolated outposts, these solar kits are very valuable, as they provide all the juice needed for many smaller electronic devices. These means a lot fewer batteries have to be flown or trucked in. For long range Special Forces patrols, there is usually no resupply for a week or more, while deep in hostile territory. The solar panel is the primary method for resupplying batteries.
The next device is the hand crank generator. The U.S. Department of Defense has developed a 450 gram (one pound) model that will allow recharging of many military electronic devices. Some troops have already adapted some civilian hand-crank units for this purpose, which was one of the things that motivated the military to create an official military model. The best thing about the hand crank generators is their efficiency (88 percent). Your typical soldier burns the equivalent of 5,000 watt-hours a day. By spending some of that energy turning the crank, for every 160 calories expended, you get 100 watts of power for battery recharging.
Troops get killed driving, or flying, supplies into a combat zone, and one of the most common items is fuel. Fewer loads of fuel being brought in means fewer casualties.