I don't get why Americans are hating on hydrogen fuel cells so much, but in Korea, half of the eco-friendly bus market is basically on hydrogen (note: the gov uses all kinds of weird terms and stats, so I really can't nail down the actual number). There are lots of electric buses, but they're too heavy and not great for the tight corners and hills that are everywhere in Seoul. FCEVs are lighter and more powerful, so bus drivers seem to prefer them over BEVs. However, hydrogen buses are about twice as expensive as battery buses from China.