Green hydrogen is no solution

I NOTE your article on green hydrogen (“£30m hydrogen network project aims to replace natural gas”, The Herald, May 5) .

The production of green hydrogen, that is hydrogen produced by the electrolysis of water using renewable energy such as electricity from wind or solar power, has a positive future but it is not a golden “get out of jail” card. It is important that readers are equally aware of the negatives and regard with a large dose of cynicism the hype associated with the term “the Hydrogen Economy”.

Hydrogen would normally be burnt in air and a proportion of the oxygen atoms combine with nitrogen in the air to form NOX (highly toxic oxides of nitrogen). Unlike methane, there are no carbon atoms for the oxygen atoms to combine with, so a higher proportion combines with nitrogen to form NOX. For this reason burning hydrogen in air produces up to six times as much NOX emission as burning methane in air. There is therefore a seriously increased health risk of burning hydrogen for heating as compared to burning fossil gas. High NOX levels in our atmosphere are already a serious health issue. Burning hydrogen for industrial purposes will require very significant challenges to remove NOX emissions from the exhaust. Just as challenging as for CO2.

Using hydrogen in fuel cells eliminates the pollution problems but hydrogen has a low energy density and is very light weight and readily escapes into the upper atmosphere. For this reason it is not found naturally in high concentration on Planet Earth. It has to be produced, highly compressed and stored at extremely low temperatures so that it can be transported to where it is needed. All the required technology is available to do this but, and it is a big but, it comes at huge capital and operating cost to provide the necessary infrastructure. The so called “Hydrogen Economy” is never going to deliver cheap energy and we all need to get used to it.

Politicians need to spend more time telling the electorate the truth and determining how to protect businesses, the population and, crucially, the poor from the ever increasing energy costs of the essential carbon free future. Norman Mcnab, Killearn.