What is the role of hydrogen?

‘Green’ hydrogen, made by electrolysing water using renewable electricity, is a clean technology. However, it is a highly inefficient use of energy, with a roundtrip efficiency (converting from power to hydrogen and back to power) of under 40%.

This fuel needs to be reserved for difficult-to-decarbonise sectors like heavy industry and shipping. Widespread deployment of hydrogen would make net zero more difficult and costly to reach, by taking up scarce clean energy capacity. It would also open the door to ‘blue’ hydrogen, made from methane, which some studies show would be worse than coal for the climate due to unavoidable methane leaks (‘fugitive emissions’).

Hydrogen’s clear unsuitability for home heat is well documented, but it is being promoted heavily by powerful fossil fuel interests looking to preserve the market for methane, and to avoid the gas grid becoming a stranded asset.

Green Hydrogen

• Made by electrolysing water using renewable energy
• Likely to be required in difficult-to-decarbonise areas, such as industrial
• energy, shipping, aviation & seasonal power storage
• Energy inefficient & far more expensive than heat pumps, which deliver around 6 times more heat per unit of electricity than green hydrogen.
• Limited supply until we have surplus clean power/nuclear fusion later this century.

Blue Hydrogen

• Made from methane using unproven carbon capture and storage technology – relying on us trusting fossil fuel companies to safely capture all the CO2 and store it permanently.
• Unavoidable leaks of methane (‘fugitive emissions’) mean some studies conclude it would be worse than coal for the climate
• Promoted by fossil fuel industry as route to continue extracting methane, despite huge damage to environment and cost to homeowners.
• Encourages fracking: The lobbyists aim to secure permission to frack for natural gas to produce hydrogen. Fracking involves unavoidable leaks of potent greenhouse gas methane (‘natural gas’) into the atmosphere – BBC May 2021
• Public subsidies: Incredibly, fossil fuel companies are beginning to ask for public money to pay for the infrastructure to capture carbon.
• The head of the hydrogen industry association resigned in 2021, warning he would be betraying future generations by remaining silent on the problems with blue hydrogen. A very strong sign that our Government is taking us in the wrong direction.

All hydrogen

• Risk of explosion: Due its very small molecule size compared to natural gas, hydrogen can escape through pipework, and since it is odourless, this does present the risk of explosion.

It is likely that hydrogen will have a role to play for tough-to-fix challenges like aviation and steel manufacture, but that needs to be ‘green’ hydrogen produced using renewable power.