Powering the cyber soldier

Researchers in the US have developed a lightweight power generator that may power the image displays and laser range finders of tomorrow’s high-tech infantryman.

The ‘man-portable generator’ is being developed at the US Department of Energy’s Pacific Northwest National Laboratory for the US Army’s Communications-Electronics Command.

The US army faces an increased demand for power as it pursues futuristic cyber systems for soldiers, such as heads-up displays and global-positioning systems. The man-portable generator would supply the power needed for these advanced technologies by generating 15 to 25 watts of power inside a system weighing 10 times less than batteries soldiers currently carry. The increased power density would allow soldiers to either reduce their load or greatly extend their missions.

In March 2001, PNNL engineers reached the first major milestone in development when they demonstrated a full-size, advanced design fuel processor that converts methanol into hydrogen. Because hydrogen wouldn’t need to be stored or carried, the fuel processor would reduce the weight and risk associated with portable power systems.

‘We’ve taken a significant step toward light-weight power generation with this breadboard-stage fuel processor,’ said Ed Baker, PNNL project manager. ‘Our system produces the hydrogen that fuel cells need to create power. We expect to create hydrogen from liquid fuels such as methanol, synthetic diesel and possibly military jet fuels. Each of these is more readily available and easier to carry than hydrogen.’

Based on the results of the breadboard-stage development, PNNL engineers are designing a prototype fuel processor and hope to have it tested within the next year. Then, they will face the challenge of integrating it with other components of a complete power system, including a micro-scale fuel cell, fuel storage and a delivery unit, and a battery for peak power.

PNNL engineers based the fuel processor design on 1- to 10-kilowatt prototypes that they have built for use in automobile power systems.

The processor being developed for the man-portable generator consists of four micro-technologies including a combustor, vaporiser, primary conversion reactor and a gas cleanup device.

It uses a proprietary catalyst to produce hydrogen from hydrocarbon fuels and reactions are said to take place within small channels of a catalytic converter. These micro-channels enhance heat and mass transfer rates and significantly speed up chemical reactions, which reduces the device’s size.

In addition to the reduction in weight, engineers at the army and the laboratory expect the portable generator to be less expensive than batteries.