GREEN hydrogen is not a solution for Aberdeen (The world’s net-zero capital?, Mar 2) – for the simple reason that the production of enough green hydrogen through the electrolysis of water would require a huge amount of renewable energy.

For example, the Northern Gas Networks scheme to supply 15.7 million homes with hydrogen would require around seven times as much wind-generated electricity as is currently produced in the UK. Moreover, generating electricity to provide the energy to electrolyse water into hydrogen and then using the hydrogen for heat is inherently inefficient.

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Direct use of electricity is cheaper, more efficient and would require much less generating capacity. Ed Matthew, associate director at independent climate and energy think tank E3G, says hydrogen is the wrong choice for heating homes. Green hydrogen, he says, is four times less efficient than using heat pumps. “Hydrogen is being pushed by the gas industry – beware,” agrees Dave Toke, reader in energy politics at Aberdeen University. He calls it “the start of one of the greatest pieces of greenwash that has been committed in the UK.”

It’s currently hard to see how even green hydrogen can have more than a very specialised place in a fully decarbonised economy. Hydrogen fuel cells are currently being used for buses, and mass transport is of great importance in decarbonisation. But it seems likely that electric buses will make more sense than using large amounts of renewable energy to produce green hydrogen.

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The priority uses for renewable energy are to replace gas and coal in power stations and to heat homes and other buildings with electrically driven heat pumps.

Sturgeon’s claim that Aberdeen can become the “net-zero capital of the world” is an imperialist pipe-dream. But if the transition away from oil and gas by investing rapidly in the development of renewables, retrofit insulation and mass transport is grasped by the Scottish Government in time, Aberdeen could still become the climate capital of Scotland.

Mike Downham

ABBI Garton-Crosbie does outline the possible uses of hydrogen fairly well but she has, however, missed the most glaringly obvious and deeply suppressed case for the use of hydrogen in vehicles.

There is no need for the interjection of a fuel cell between the hydrogen and the wheels: you can burn hydrogen in an internal combustion engine with no more need of alteration than that required for liquid petroleum gas.

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Arguments from vested interests and obsessives against this, such as the danger of explosion and lower thermal efficiency, do not wash. It is no more dangerous than liquefied petroleum gas. Any suggestion of lower thermal efficiency is more

than cancelled by lower cost and, above all, the fact that the only emission at the end of the process is the same amount of water as was required to produce the hydrogen in the first place.

I read recently the statement that we will go down in history as the only society which ever destroyed itself because the alternative was not cost-effective. I would go further and suggest the the situation is even worse in that we will take most of the rest of the inhabitants of the planet with us – not that that seems to be of the least concern to the oil companies, arms manufacturers and a particular breed of politician of whom the world has a totally unnecessary surfeit.

Les Hunter

BOTH wind and nuclear generators need other generators (such as a gas generator or similar, or pumped hydro) to accommodate the ups and downs of electricity demand patterns, as well as other generators and for wind, the weather (Should nuclear be part of Scotland’s energy future? Experts weigh in, Mar 3).

Prof Allison is inaccurate in saying “offshore wind is available only 30% of the time at best”. In 2022, Scotland’s offshore and larger onshore wind farms generated at scale – day-average outputs of 2GW (two Tornesses, a good chunk of Scottish electricity consumption) or more – for two-thirds of the year (237 days), and at lower output the rest of the year.)

In future, the need for other generators (often fossil-fuelled) may be lessened if other options, such as large scale-storage and/or electrolysis to make hydrogen, are deployed. Electricity users – in industry, commerce, vehicle-charging, and maybe households too – may increasingly play a part: those who can and wish to turn up and down consumption according to electricity availability or price. Many of these approaches need further technical and commercial advances to grow as fast as we’ll need them.

Your readers doubtless have their own views on nuclear power and wind farms. My own view, for what it’s worth: in Scotland, the economic and practical case for new nuclear is particularly weak, given the abundant wind resource here. My vote: pioneer and roll out low-carbon energy storage, and other ways to best utilise Scotland’s electricity, especially when it’s windy.

Susan Brush