Battery of H2 - what will win out? Depends. Some say that the solid state battery is a game-changer, since energy density (kW per kg output) is today's battery's biggest handicap. Renewable energy generation may well have begun to churn out enough energy to start storing it through H2 generating by then. H2 is sort of a natural for transporting goods. The true economy of scale for H2 will arrive by including passenger vehicles too.