Air pollution is the top environmental risk to human health in the UK. We need to ensure that the energy we use does not continue to pollute our air, which causes particulates to enter our bodies through the lungs and damage vital organs. The World Health Organisation has guidelines which highlight the importance of clean air to protect the planet and all inhabitants. Hydrogen is a clean fuel source, you can start with water and renewable electricity, make hydrogen, use the hydrogen, for it to just return back to water. There really is no other energy provider which can be cleaner than hydrogen.