The Power Shorts and the Recharge Sleeping Bag, as the products are known by, were both developed by the Electronics and Computer Science Department at the University of Southampton. The science behind them is interesting. As the fabric that they are both made of is squashed or deformed, it "harvests kinetic energy" which powers up your phone. At the same time, temperature changes experienced by the sleeping bag also help power up your handset.
One day walking around in the Power Shorts will add four hours of battery life to your phone while the sleeping bag returns eleven hours of battery life to your device. Both the shorts and the sleeping bag will be in use during the U.K. festival, so even if the music is bad, those wearing Power Shorts or using the Recharge Sleeping Bag will at least be able to play Hanging with Friends all weekend.