my older brother worked on hydrogen powered turbines while working at P&W decades ago... He also made a hydrogen powered fuel cell for a science fair project back in the 60s.Hydrogen cars are available for sale or lease in Southern California. The Toyota Mirai, Honda Clarity and Hyundai Nexo. There aren't many places to refuel yet.
Right around the corner, all it takes is money and compliant tax payers.
It would actually make sense to use NG to power vehicles.
JR