Just thought Id forward a new Pentagon announcement intended to prompt a competitive solution to the problem of lightweight power generation for the increasing number of electronic devices carried by grunts and Joes in combat…
The Director, Defense Research and Engineering, John Young today announced a public prize competition to develop a wearable electric power system for war fighters. The competition will take place in the fall of 2008 and the prizes are $1 million for first place, $500,000 for second place and $250,000 for third place.
The essential electronic equipment that dismounted warfighters carries today — radios, night vision devices, global positioning system — runs on batteries. This competition will gather and test the good ideas for reducing the weight of the batteries that service members carry. The prize objective is a wearable, prototype system that can power a standard warfighter’s equipment for 96 hours but weighs less than half that of the current batteries carried. All components, including the power generator, electrical storage, control electronics, connectors and fuel must weigh four kilograms or less, including any attachments.
Prizes will be awarded to the top three teams in a final competitive demonstration planned for the fall of 2008. At this “wear-off,” individuals or teams will demonstrate their prototype systems under realistic conditions. The top three competitors that demonstrate a complete, wearable system that produces 20 watts average power for 96 hours but weighs less than 4 kilograms (~8.8 lbs) will win the prizes.
A public information forum will be held in September in the Washington, D.C., area to brief potential competitors on the technical details, the competition rules, and qualification requirements. Competitors must register to participate in the prize program by Nov. 30, 2007. The competition is open for international participation; however the individual or team leader must provide proof of U.S. citizenship. Details on the forum, as well as contest registration and rules are posted on the Defense Research and Engineering Prize Web site.
I guess you can join global battery directory at http://www.global-battery-directory.com to gain more information.
I’m guessing that Larry Rome’s power-generating backpack will contend for this prize. Much easier to create the power (and store it) thru movement than to just carry the power around.
http://www.newscientist.com/article.ns?id=dn7970
I made some quick and rough calculations. First the requirements: 20 W continuosly for 96 hours, with an intermittent peak power draw of 200 W. That is 2 kWh and the total weight of the system needs to be under 4 kg.
Lithium ion batteries top out at 160 Wh/kg, so you need chemical energy for this to work (gasoline is ~10 kWh/kg). The peak power draw probably means you want a chemical power/battery power combo, as a chemical system is optimized for a specific power level.
What chemical energy to use? I see two approaches:
One is to go buy a state-of-the-art fuel cell at about 25 W, a hydrogen container and a battery. Combine these with some electronics and you should make the specs. Problem here is that fuel cells are tricky to work with, and hydrogen is even worse. I’m not sure I would want to carry a hydrogen tube on a battlefield..
The second option is to buy a small liquid-fuel engine, such as an R/C engine, an electric motor acting as both generator and starting motor, a battery and a fuel tank. I looked at R/C engines and the smallest one I found was called “OS MAX-10LA” with a deplacement of only 1.6 cc, weighing 110 g. That tiny engine still produces 0.2 kW, so it only needs to operate for 15 minutes every other hour or so. The main problem with this is the noise level of the engine: although ~80 dB is low for an R/C engine, it is quite loud if there is somebody close you’d rather not be heard by.
A possible third approach might be a direct methanol or other liquid fuel cell. But I have not seen these available for purchase, so unless you are working for some large Japanese electronics manufacturer this is probably a non-option. (And if you are: sorry, competition is US-nationals only.)
If I was in college, I’d gather a team, buy an R/C engine and see how much electricity it can produce and what fuel-consumption it has. The parts are only ~$200 total for that approach.
Someone here should pull the obvious spam comments to maintain the integrity of this site (if there is any.)