Hydrogen fuel cells aren't gaining a huge amount of traction in cars, where there's a steady move toward electric. But what about regional railways, where long ranges and a lack of powered rails makes electric trains impractical? Alstom thinks that makes plenty of sense -- the French firm has introduced one of the first hydrogen fuel cell trains, the Coradia iLint. The 300-passenger locomotive can travel up to 497 miles at a reasonably brisk 87 miles per hour, all the while spewing nothing more than water. Hydrogen gives it the freedom to run on non-electrified rails, and it's considerably quieter than diesels -- helped in part by batteries that store unused energy.