Replacing natural gas with green hydrogen is being touted by many as a key enabler to net zero. It is not in dispute that hydrogen will deliver a far superior UK carbon footprint as it combusts to water. But what will hydrogen do to domestic energy prices? Highlighted as the most probable route to produce at-scale green hydrogen is water electrolysis. Renewable electricity is used to split water into hydrogen and oxygen. We have electricity that can be supplied to the consumer but we use the electricity to produce hydrogen. To my mind, that must mean that the cost of hydrogen per kWhr has to be more expensive than electricity. This is the same for blue hydrogen where natural gas is converted to hydrogen using reforming technologies with a CCS plant bolted on to deal with the CO2 by product – currently 95% of all hydrogen is synthesised by reforming. Hydrogen being more expensive than electricity will completely change the consumer’s view of an energy source for space heating. Once again I ask myself if the hydrogen economy has been thought through? I do like green hydrogen; I consider an immediate use is to provide a hydrogen natural gas blend of 20/80. Domestic burners can utilise that mix with minimal disruption. But 100% hydrogen for space heating as the low carbon solution – I have serious doubts. Presently hydrogen is synthesised from reforming methane with much of the world’s hydrogen output being used to produce ammonia via the Haber-Bosch process. Here hydrogen and nitrogen are reacted to produce ammonia. Both processes are energy intensive with consequent large greenhouse gas emissions. Let’s make green hydrogen and use it for producing green ammonia for fertilisers and a myriad of other useful products.
Energy Voice 23rd June 2020 read more »