I heard an article on that.

They claim a set, one on each knee joint, produces a steady 5 watts of power. Not bad. Particularly when you find out it doesn't make walking any harder. Neat trick.

As I understand it they don't use the joint motion in most of the normal stroke but rather just the very last of each cycle when the body is having to expend energy to decelerate the joint. This is usually entirely wasted energy.

The commentary from users was that after taking them off they missed them because they had to start decelerating the joint at the end of each stroke for themselves so it felt like they were having to work harder Not wearing the generator units.

I could see a day when all your electronic gear was on a central energy harness that took power from a set of these units and automatically kept the GPS, cell phone, PDA, laptop and a flashlight all topped up and ready to go.

The military is looking closely at similar devices. In part because a study revealed that the average infantryman carries something like five to seven pounds in batteries. If they could get by with a couple of pounds of batteries and these units were only a pound a piece they would be ahead of the game in weight and, because they wouldn't need resupply so often, you could cut the number of supply convoys.

Word I hear is that the real kicker will be solar powered extraction of atmospheric water. That could cut the number of transport convoys by a bit more than a third.

Wasn't there a story about a kid who grew up on a moisture farm?