Electricity has a transmission problem though - there are some parts of the world with lots of clean energy, which we can't fully take advantage of because we can't transport electricity that far. Hydrogen allows us to use that clean energy to power cars in other parts of the world, since you can produce hydrogen in those places and then ship it to places without much clean energy. Also you can presumably stop and start hydrogen production as electricity demand changes (ex. Only produce it on sunny windy days where there is excess electricity) allowing you to shift the demand curve more easily than with electric cars.