Most of the fleets I've assessed have been using gray hydrogen with the 'promise' of making it green at some point.

Whistler BC's bus fleet used green hydrogen, but they shipped it 4,500 kilometers from Quebec on trucks or trains, so the transportation carbon debt was huge. Despite tons of low-carbon hydrogen in the province and a full set of hydrogen for energy businesses there wasn't enough green hydrogen manufacturing capacity locally. So weird.

Barcelona's new hydrogen bus fleet, the 50% of it that is operational 18 months after delivery, is using green hydrogen manufactured locally. That is very, very rare.