shoe chargerA U.S. startup has devised a shoe insert that can transform energy generated from walking into usable energy to power portable devices, including mobile phones, GPS devices, and fitness trackers.

SolePower, is hoping to earn $50,000 US to take the product development further, and aims to charge a mobile phone after 2.5 miles (four kilometers) of walking.

Beta testing is expected this summer, with full production and shipping expected by the end of 2014.

A pledge of $75 buys you an insole, if you live in the US. For international backers, you’ll need to pledge $100 plus $15 shipping.

The insole fits into any shoe, with the usable electrical power stored in a rechargeable battery that you fasten around your ankle, which can then be plugged into a portable device for on-the-go charging.

This could certainly be convenient for mobile phone users who burn through their batteries throughout the day, wearers of fitness trackers might also enjoy a fringe benefit to all that moving about.

Credit: Canoe