I have been reading a number of articles about changing to hydrogen cars and how it would result in a decrease in pollution. While it is true a hydrogen car would be a number of times cleaner than a regular gas car, I have a few doubts about how clean the hydrogen making process would be. If hydrogen obtained from water, wouldn't it require a great deal of energy to get the hydrogen out of it? Wouldn't the energy required to do this come from oil and the more traditional non-green energy sources? Overall, is the process for obtaining enormous amounts of hydrogen overall green at all?
the fossil fuel powered split would only be necessary at the very beginning of the process. Hydrogen releases more energy than is required to split H from O2, so you'd be producing Hydrogen by means of a Hydrogen powered process. green all the way around.
switching to hydrogen power would do way more than just decrease pollution. It would also make energy very cheap because the process of splitting water is relatively simple. You could literally have a mini power plant behind your house producing a great, clean source of energy, that powers your entire house, and your car. Fuel stations could produce hydrogen on location.
In large cities, for safety purposes, there would probably still be a reliance on energy companies, to prevent having large quantities of such an explosive within city limits. Imagine if a city were to start to burn with pockets of hydrogen everywhere? I'm reminded of the great chicago fire and the san francisco fire.
but yes, you can totally have a green process for splitting hydrogen from oxygen.