Sometimes our dependency on battery-charging devices seems ironic, considering the abundance of energy around us that is being generated every day by sources as mundane as the human hand, footsteps, and lightning, which strikes the Earth dozens of times per second. (See related photos: “Immense, Elusive Energy in the Forces of Nature.”)

A typical lightning bolt produces between 1,000 and 5,000 megajoules of energy, enough to power a car for about 180 to 910  miles (290 to 1,450 kilometers), and certainly enough to charge a cell phone, if you happen to be standing near a bolt and a transformer that can regulate the voltage. Scientists at the University of Southampton in the United Kingdom recently succeeded