Cool, I was looking for the efficiency of the Sabatier process. If people are prepared to use electrolosis with a end to end efficiency of ~ 40%. Using the Sabatier process to produce methane begins to look good to me. Just as green as the methane is produced from carbon dioxide and water. And it is much cheaper to produce pipes and tanks for methane and it should be able to be used in all the current natural gas infrastructure (compared to only 20% of the gas in these lines being able to be replaced with hydrogen). It seems to me anywhere where the gas has to be stored or moved the Sabatier process would win economically.