Orlando airport tests cleaner hydrogen-powered internal combustion engines . Smoother , quieter engines require million-dollar fueling stations . Until somebody takes that first step , there 's always going to be the 'what Score: 6 Hydrogen engines cheaper than hydrogen fuel cells , but they use more hydrogen .
Orlando airport tests cleaner hydrogen-powered internal combustion engines . Smoother , quieter engines require million-dollar fueling stations . Score: 6 Hydrogen engines cheaper than hydrogen fuel cells , but they use more hydrogen .