Treehugger has a follow-up on a story they posted last year, about a University of Pennsylvania researcher who figured out a way to harness the body’s movements while hiking to generate electricity – faster and more reliably than those solar chargers that have been on the market for a while.

New studies on the design now reveal the generating mechanism – while adding a slight amount of weight to the pack – reduce the vertical jarring force by an unbelievable 86%.

The researcher’s company wants to get commercial models available by this time next year. Here’s to hoping a). you don’t have to take out a loan to buy one and b). they find a way to reduce the size of that metal frame. Or at least add some notches so we can hang carabiners off of it.