During a battle, the ability to move troops swiftly and without detection can mean the difference between victory and defeat. The U.S. Army is developing tents and uniforms made from flexible solar panels to make it more difficult to track soldiers.
Jean Hampel, project engineer in the Fabric Structures Group at the Army's Natick Soldier Systems Center, said the need to reduce the Army's logistics footprint spurred interest in developing lightweight solar panels. "We want to cut back on the things that soldiers have to bring with them," including generators and personal battery packs, Hampel said. In modern warfare, portable power for communications technology is every bit as important as firepower and manpower.
The Army is testing flexible solar panels developed by Iowa Thin Film Technologies that can be layered on top of a tent, or rolled up into a backpack to provide a portable power source. Tents using solar panels made from amorphous silicon thin film on plastic can provide up to 1 kilowatt of energy, which is sufficient to power fans, lights, radios or laptops, according to Hampel.
Yes, these are the same solar panels as the ones I've taken on RAGBRAI the last two years to power my cell phone, camera, MP3 player and maintain my stereo battery. They are super light, super durable, and they work well!
Hampel said using solar tents would reduce the need for diesel powered generators and diminish the "thermal signature" that enemy sensors use to track troop location. She said soldiers could carry smaller flexible solar panels and unfold them during the day to collect energy to recharge their personal communications equipment.
This would enable soldiers to lighten their loads of extra battery packs, which are sometimes left behind and reveal the soldiers' presence, according to Hampel. While Iowa Thin Film's PowerFilm products are ready for field use, the Army's "type classification" process, which enables them to be purchased in bulk, will require one to two years of additional testing.
Iowa Thin Film's plastic-based products are an improvement over previous generations of solar panels that layer the panels onto less-flexible metal, company spokesman Mike Coon said. He said the amorphous silicon products are also cheaper to produce because the panel connectors that centralize the collected energy are laser-welded during the production process; standard photovoltaic panels must be individually connected.
Coon said standard PV panels are uniform in size, but his company's products can be cut into modules of different sizes, which maximizes the efficiency of power collection. Coon said Iowa Thin Film custom-made the solar panel fabric that is layered onto tents for the Army and the smaller foldable panels became commercially available in late 2003. The PowerFilm products are currently more expensive than traditional solar panels, but Coon said improvements in the manufacturing process will enable them to be cost-competitive within two to five years.
The Army's long-term vision is to have solar panels that can be camouflaged into tents or even uniforms, Hampel said. Her group is working with Konarka Technologies to develop nanotechnology-based solar panels that can be woven directly into fabric. Konarka's technology replaces silicon with dye polymer plastics that transform any kind of light into electrical energy.
Using plastics as the basis for solar panels will result in a faster manufacturing process than silicon fabrication plants, said Russell Gaudiana, vice president of research and development at Konarka. Gaudiana likened the process to producing photographic film (he previously worked at Polaroid), and said the solar panels can be printed in any color. "Our solar panels can be woven into any fabric, including tents, clothing or roofing material," he said.
The technology would reduce the cost of installing solar panels on new buildings because they could be applied as part of the roof itself instead of as an additional step, according to Gaudiana. And instead of having a small solar panel on a handheld or notebook, the entire surface area could be used to recharge the batteries.
Gaudiana said the technology is still in the research phase, and declined to give a timetable of its availability. It would likely be cost-competitive with other technologies initially and would be cheaper when it is mass-produced.
Solar energy consultant Paul Maycock of PV Energy Systems said the Army has been interested in flexible solar cells for about 10 years. "It's very important that we have reliable portable electricity for telecommunication-based military," Maycock said.
Companies have been producing solar panels using amorphous silicon on steel for several years, but several failed because they could not advance the technology quickly enough to keep up with rigid photovoltaic systems, Maycock said. He said the Army has continued to fund development of the technology because the materials to date have been too heavy and not cost-efficient.
"The technology has thousands of applications" if it can be made at affordable prices, Maycock said. "Imagine that if you go to the beach, the shade could be used to power a TV."
By John Gartner
02:00 AM Jun. 29, 2004 PT