“…ITM Power are proposing to inject hydrogen directly into the gas grid, and have recently worked with Thüga Group in Germany to do this, using PEM electrolysis (ITM Power, 2014b). There are currently limitations on the amount of hydrogen permitted in the gas grid, mainly owing to the physical properties of hydrogen (Haines et al, 2003;Melaina et al, 2010), and the legislation on pipeline quality of gridded gas. This is being reviewed, but there are other barriers to hydrogen injection to the gas grid.…”