In prototype hydrogen-powered cars, the fuel is stored in large tanks behind the back seat. The tanks are insulated with 70 layers of aluminum and glass fiber in an evacuated space between two metal skins. Tests have shown that the prototype tanks will not explode even at temperatures as high as 900 degrees C for more than an hour and could withstand accidents better than conventional gasoline tanks. The hydrogen availability problem may eventually be solved through clever chemistry. Electricity is not necessarily needed to split water into hydrogen and oxygen.
Visible light can do so in the presence of an appropriate catalyst.
Researchers at the Tokyo Institute of Technology have shown, for example, that light from an ordinary lamp can split water when powdered cuprous oxide is used as a catalyst. Others have shown that titanium dioxide and molybdenum catalysts can do the job. The efficiency of these processes must increase greatly before they become practical. Burning hydrogen is not the only way to derive energy from it. Liquid hydrogen is burned to lift the shuttle into space, but in orbit, the same element is used to produce electricity needed during a mission.