Current and future developments in energy production promise to lower the soldier’s combat load and reduce the logistical footprint, said an army systems expert. Current technology could allow soldiers and their vehicles and equipment to one day passively capture solar energy, which will automatically charge batteries used for network communications and other tasks, said Major Mark Owens.

Owens, a system coordinator at the Office of the Assistant Secretary of the Army for Acquisition, Logistics and Technology, spoke at an Operational Energy forum, in the Pentagon.

Now in research and development is an apparatus Soldiers would wear to reduce musculoskeletal injury and increase performance. The device would also generate energy for batteries when the soldier is walking downhill and “braking,” he said, much like energy-regeneration braking used in electric vehicles.

Another possible similar development in the future would use the oscillating motion of a soldier’s rucksack to capture energy – up to 50 watts worth, Owens said. “You obviously wouldn’t want to oscillate when going down a mountain, so it could be locked in place.” A similar passive-energy collection device could be in a vehicle seat. The weight of the soldier could generate power, he said.

Someday, thermal electric devices could line soldiers’ armour, producing a mild air-conditioning effect of cooling down a soldier by about five degrees Fahrenheit, he said. It would have an added benefit of reducing water intake and the associated weight of carrying a lot of water.

Smart textiles could someday route energy through the fabric of the soldier’s combat uniform, reducing the need for cables and other devices connecting the battery and networking communications, he offered.

Why the Army’s sudden increased interest in reducing weight and increasing energy efficiency?

New network communications gear worn by soldiers keeps getting heavier and heavier, he said. The army predicted that in the future, the power needed to generate these devices will increase from the current 3 to 4.5 kg to 6.3 kg for a 72-hour mission.

That doesn’t seem like much, but the effect of new gear dismounted soldiers carry makes the load heavier and heavier, Owens said. At some point, the army began to ask itself “Is the juice worth the squeeze?”

Consider that during World War II and Vietnam, the average soldier hauled about 36 pounds of stuff, he pointed out on a slide. During operations in Iraq and Afghanistan, that load increased to 35 kg.

“If you have loads for dismounted infantrymen of from 30 to 60 kg, you begin to degrade their ability to manoeuvre, degrade their situational awareness and there’s tremendous impact to the musculoskeletal system, with increased probability of injuries and long-term consequences,” he said.

Owens was quick to point out that much of that added weight increased the chances of soldier’s survivability on the battlefield in the form of increased situational awareness through better communications and more effective firepower. However, at some point, a soldier can only carry so much, so there has to be a sweet spot.

To get to that spot, the army in 2009, started looking at how technology could contribute to decreasing the soldier’s load from a power perspective, since food, water and body armour were already at their limits in possible weight reduction, he said.

In 2003, 90 per cent of the batteries purchased by soldiers were non-rechargeable, he said. So, if a soldier went out on patrol, he’d come back with maybe 60 per cent of the charge still in his batteries, but toss them and get new ones for the next day’s patrol, just to be on the safe side.

The army is reversing that trend today, with lithium-ion rechargeable batteries that are more powerful, weigh less and come with charging stations, he pointed out. The newer batteries also last about 25 per cent longer.

The chargers that were used in 2003 could not be run by solar or vehicle power and they were less rugged than the ones now being produced that can use alternate energy sources, and can run off AC or DC current.

Another problem is that the 2,590 batteries soldiers have been wearing, while powerful, are also a potential safety hazard when penetrated by rounds or shrapnel. They’re “not something you want to have on your body when that happens,” he said.

An army programme of record for 2016 through 2020, will result in better battery and charging technologies getting out to soldiers in the field, Owens said. For example, rechargeable batteries that are flattened out and flexible with charge indicators on them will be worn by soldiers to supply their network communications and other gear.

Universal charging stations are part of that programme, capable of operating off alternative energy sources or even drawing energy from partially charged batteries, he added.