Hydrogen is not a fuel source since it does not occur naturally in large amounts here on Earth. You can of course produce hydrogen using electricity, and then burn it in an engine. But then you are just using it as a type of battery, and for that it is more expensive, less efficient, and harder to recharge than current lithium batteries. That is why hydrogen is not being used in cars, and probably never will.This is good and all but lithium has a fixed life as raw resources eventually dwindle. Let alone the pollution aspect to make and dispose of them. The abandonment of hydrogen or other fuel sources concerns me.