<http://schema.org/about>
"When we see personal chargers, they're almost always based on absorbing energy from the sun. Once in a great while, we also hear of new personal wind-powered chargers. But we almost never hear about water-powered personal"^^<http://www.w3.org/2001/XMLSchema#string>
<http://www.treehugger.com/clean-technology/river-powered-personal-charger-expands-energy-options-for-the-outdoorsy.html>