Grey, Brown, Blue – what about green hydrogen?
Hydrogen can also be produced by the electrolysis of water (using an electric current to break water into its component elements of hydrogen and oxygen). The resulting hydrogen can be used later to return electricity to the grid via a fuel cell. Grey, blue, and green are the three forms that hydrogen can take. The cleanest of the three is Green hydrogen, if produced from renewable energy sources. If this electrical current is produced by a renewable source (e.g. Solar PV or a wind turbine), the clean hydrogen produced is known as green hydrogen. Hydrogen gas has the highest energy content of any fuel, as it has the capability to store substantial amounts of energy in a small amount of hydrogen. When there are surplus renewables, prices will drop, becoming the most cost-effective.
Green Hydrogen produced from renewable energy such as, Solar PV or wind can play an important role in our national energy strategy. It can help decarbonise transport, heating and industrial processes such as steel and cement making as well as be used for long-term energy storage. Hydrogen is a clean fuel that, when consumed in a fuel cell, produces only water, electricity, and heat. Because of its high efficiency and almost no emissions, green hydrogen has the potential to reduce greenhouse gas emissions!
However, there is another problem associated, producing such high quantities of green hydrogen would require massive amount of renewable energy. Currently, green hydrogen is largely being produced at pilot projects only. While hydrogen technology has a lot of potential, it still faces significant obstacles.