No emissions, only water: Cadent decarbonising the gas grid with hydrogen

No emissions, only water: Cadent decarbonising the gas grid with hydrogen

Gas plays an enormous role in the UK energy system. It heats our homes, cooks our food and helps create the electricity that we use every day.

But the UK’s gas network is also responsible for 35% of the country’s total greenhouse gas emissions, meaning decarbonisation is essential if the UK is to meet its current ambitious climate target of net zero emissions by 2050.

Decarbonising it will be a major undertaking, necessitating changes to the UK gas network on a scale not experienced since gas first arrived in homes more than 60 years ago.

Hydrogen offers potential as a zero or low carbon energy source alternative. This is because when hydrogen is burned it doesn’t produce carbon dioxide (CO2), only water and heat.

A first-of-its-kind trial is currently underway in the UK investigating whether the gas network could be adapted to transport hydrogen, either as a blend with natural gas or a complete conversion to hydrogen.

Led by the UK’s biggest gas distributor Cadent, the £7m year-long HyDeploy project is due to begin later this year and will find out if blending hydrogen (up to 20% volume) with natural gas could be an easy way to reduce CO2 emissions from home cooking and heating, without changing customer appliances.

“The key point with hydrogen is that when it is burnt it produces no emissions, only water vapour, unlike natural gas which produces carbon.”

“The UK’s gas network, which billions of pounds has been invested over decades, can continue to provide heat to the 85% of homes that are connected to it and it can help to meet climate change targets by delivering hydrogen, which is zero carbon when used,” Andy Lewis (pictured above), Cadent’s Future Networks Manager, tells H2 View.

“The HyDeploy project looks to demonstrate that a hydrogen blend (20%) can be safely transported and efficiently utilised in a live gas network at Keele University in Staffordshire.”

“Keele University is the ideal place to host a project like HyDeploy because the university entirely owns and operates its own gas network, so we can be pioneering.”

The project achieved a significant milestone at the end of 2018 when the safety case was approved by the Health and Safety Executive (HSE) for the transportation of hydrogen.

“This means that the project team can start hydrogen injection into the Keele network this summer,” Lewis continues.

“This approval was granted after scientific, operational and health and safety work was carried out to show that a hydrogen blend is no less safe than what the gas network does today.”

“The key point with hydrogen is that when it is burnt it produces no emissions, only water vapour, unlike natural gas which produces carbon.”

Assuming success at Keele, the project will then test the same blend in a sample set of around 660 homes in the North East and around 700 in the North West on public gas networks – one managed by Cadent and one managed by project partner Northern Gas Network.

“At the end of these trials, we can then confirm that hydrogen is safe for widespread distribution and that customers are happy to use it. We intend to do this by 2024,” Lewis says.

Safety

The hydrogen for HyDeploy will be produced used electrolysis, which Lewis says is the most practical way to produce hydrogen for a project of this size and duration.

“It avoids the need to transport or store large amounts of hydrogen at the Keele site as hydrogen can be produced from green electricity when required.”

Project partner ITM Power will supply the 0.5 megawatt (MW) proton exchange membrane (PEM) electrolyser.

The mixing of hydrogen with natural gas is done by a purpose-built piece of equipment called the grid entry unit (GEU).

“We have calculated that if a 20% [hydrogen] volume blend was emitted throughout the UK, this would save six million tonnes of carbon being emitted every year – the equivalent of taking 2.5 million cars off the road!”

“The GEU will ensure that the correct amount of hydrogen is mixed with natural gas and that it is injected into the network at the correct pressure,” Lewis explains.

“It ensures that the amount of hydrogen injected into the network remains within safe limits and if any problem was to occur hydrogen injection would automatically stop.”

“GEUs are commonly used for injecting biomethane into the gas network in over 80 different locations throughout the UK today.”

Lewis assured that “no person or building is at risk” during the project and all aspects of safety are being closely overseen by the experts at the HSE.

“The project’s objective is to prove the safety of hydrogen blended into an existing part of the UK’s gas grid, to give everyone the right level of assurance before wider trials and then final rollout.”

“The purpose of this trial is to clearly demonstrate the science we have collated and show the hydrogen in the network is safe and policy makers have evidence on which to base their decisions around the UK’s future energy mix.”

Benefits

“One of the key benefits of a hydrogen blend at these volumes (20%) is that no appliances need to change and no pipework will need replacing. We would use the same infrastructure and appliances we have today,” Lewis tells H2 View.

“This means gas customers can decarbonise without the need to change any of their appliances or behaviour and no disruption is caused because no new pipework is required.”

“Cadent, and all gas networks, are spending billions of pounds to upgrade our gas mains to durable plastic pipes that can carry hydrogen and other gases safely, long term.”

Other benefits of the project include the continued use of an established and world class asset – the gas grid – as part of an energy mix that keeps homes warm, but also reduces the impact on environment and health.

“We will also start to develop a hydrogen supply chain which can be called upon should we use hydrogen more in the future and we can export our knowledge to other parts of the world,” Lewis says.

“This project would see a huge reduction in the amount of carbon emissions that result from heating our home.”

“We have calculated that if a 20% [hydrogen] volume blend was emitted throughout the UK, this would save six million tonnes of carbon being emitted every year – the equivalent of taking 2.5 million cars off the road!”


About the author
Related Posts
Please wait...