BMW is working on resolving a dilemma faced by backers of fuel cell vehicles – where the hydrogen comes from. The automaker is showing a 5-Series GT fuel cell proto-type that has hydrogen coming from solar-powered electrolysis. It’s part of the 2017 Hannover Trade Fair in Germany. The electrolysis process breaks the hydrogen down into two parts hydrogen, one part water. The only element that’s emitted is water, and the power source comes through solar-powered clean energy.