Leaning away from H2. Credit: Tony Webster / Wikimedia CommonsHydrogen is a rainbow. There’s green hydrogen, the version of the fuel made by zapping water with enough electricity generated by renewables to separate a hydrogen molecule from the oxygen. There’s pink hydrogen, basically the same thing except made with electricity produced from nuclear reactors, a distinction that only committed anti-nuclear activists would really care to draw. Then there’s gray hydrogen, the most common version ...