Green hydrogen is hydrogen produced through electrolysis of water using electricity that is generated without using fossil fuels. Hydrogen can be used to generate electricity with only water vapour as the emission. Through fuel cells it can be used to run automobiles, including heavy duty trucks. Through ammonia it can be used to run ships. Then it has the potential to substitute fossil fuels in manufacturing processes such as steel and cement; having already been in use for fertilizer production via ammonia. It can be stored and transported over long distances.