Alta Devices of Sunnyvale, CA, USA has announced reference designs for what it claims are the world’s lightest and highest-energy-density flexible military charging mats.
Alta fabricates single-junction gallium arsenide (GaAs) photovoltaic cells in a micron-thick thin-film that it then lifts off the growth GaAs substrate (which can then be reused multiple times to amortize its high cost). The thin-film cell can then be placed on a flexible substrate. Founded in 2007, Alta has achieved records for single-junction solar cell and module energy conversion efficiency (under one sun), as validated by the US National Renewable Energy Laboratory (NREL).
The smallest of the new charging mat (providing 10 Watt) weighs just 4.1 ounces, has dimensions slightly larger than a sheet of paper (when unfolded), and can provide power to a soldier in the field without the need for an alternative fuel source. The 20 Watt mat weighs only 10 ounces, and generates up to 120 Watt-hours of energy per day. Both designs can be folded for easy storage and transportation.
The designs are compliant to MIL-810-G specifications for temperature, humidity, shock and other environmental stresses. The mats can be married to any type of battery charging connector.
According to the US Army Research Laboratory, a soldier’s load can weigh 100 pounds, over a third of which are batteries. Alta’s technology can reduce that battery weight by 70%, saving about 25 pounds of pack weight, it is reckoned, allowing troops to extend their mission without needing to be resupplied.
The technology that makes the military chargers possible will also be introduced in unmanned systems, consumer electronics, automobiles, and a variety of industrial, remote power applications. “We have come to rely on mobile machines and devices that always need a source of power whether it be the grid, batteries, or fuel,” says president & CEO Chris Norris. “But in the next decade we will come to expect mobile power that is transparently available at all times,” he adds.
In addition to being adopted by the military to improve the effectiveness of soldiers, Alta says that its mobile power technology is targeted at manufacturers of unmanned aerial vehicles (to increase flight times), at industrial suppliers in the mining and exploration markets (to provide remote power), at consumer electronics makers (to minimize recharging), and at the automotive industry (to provide supplemental power or to increase vehicle range).
“There are nearly limitless opportunities for always-available mobile power,” reckons Norris. “We are initially targeting applications where the need is well understood and the opportunity is substantial,” he adds. “Over time, we see huge markets being enabled by this kind of mobile power.”
