Fuelling the future: A hydrogen gas guide
What is hydrogen?
Hydrogen gas is a clean alternative to methane gas. When hydrogen is used, only water is produced as a byproduct. This makes it a better choice for fuel as the UK aims to achieve net zero emissions by 2050.
What is h2 used for?
Hydrogen is not new. Already used in daily life for things like farm fertilizers and coolants for power stations, its potential extends far beyond its current applications. Hydrogen has gained considerable momentum in recent years as governments across the globe realise its potential to replace methane gas in home heating, cooking, transportation, fuel and manufacturing. Hydrogen gas can be also used in fuel cells to power electrical systems.
The UK government continues to emphasise hydrogen's role in decarbonisation while highlighting its potential to support sustainable supply chains, job creation, and leveraging British innovation.
The government estimates that hydrogen could meet 20-35% of the UK's energy needs by 2050, supporting electrification and other renewable energy sources such as wind and solar energy, which are highly weather-dependent.
Is it safe?
Multiple studies prove that hydrogen, with appropriate safety measures, is as safe as natural gas. Hydrogen has been used safely since the 1800s. Before the transition to natural gas in 1967, the UK was powered by “town gas”, which was around 50 percent hydrogen.
For more than 2 years, the H21 project, funded by Ofgem and led by UK gas networks, Leeds Beckett University, DNV and the Health and Safety Executive, has been gathering evidence to support the use of hydrogen to replace methane. This research has been assessed by the DNV team to develop a risk assessment for using hydrogen in the UK gas network.
Hy4Heat has also been a critical first step in establishing if it’s technically possible, safe and convenient to replace natural gas with hydrogen in the gas network for residential and commercial buildings and gas appliances.
Green energy for homes
The future of home heating is still being explored, but all homes could be powered differently depending on their size, location and the age of the property, as well as the people living within the property and their preferences. Choice for households is critical in the low carbon transition.
Currently, 83 percent of UK homes use gas for heating. With this in mind, replacing natural gas with hydrogen demands fewer behavioural changes and initial investment from consumers.
An alternative option for home heating is heat pumps, powered by electricity. For many larger and newer properties, heat pumps will likely be the optimal method of heating the property in an environmentally friendly and cost-effective way.
However, research from the Energy and Utilities Alliance (EUA) estimates that heat pumps will not be suitable for 37 to 54 percent of UK homes without extensive and disruptive wall and home insulation. The cost of heat pump installation can also be prohibitive, so it’s essential that all households are able to weigh up the best heating solution for themselves.
Some homes may be able to install hybrid heat pumps, which are heat pumps, supported by gas.
Hydrogen for transport
The transport sector is responsible for around 20-30 percent of global CO2 emissions. Introducing green hydrogen alongside electric vehicles presents an opportunity to significantly decarbonise this sector.
Hydrogen is likely to play a vital role in the future of heavy road transport and long-distance travel, as it can be stored and transported easily.
For larger vehicles like ambulances and lorries that operate on tight schedules and cannot tolerate extended downtime or lengthy recharging intervals, hydrogen presents a strong solution due to its ability to sustain continuous operation without significant interruptions.
Hydrogen in cars has been discussed in detail here.
Aviation
Air travel is a vital pillar of modern society, acting as a key enabler of global connectivity and economic development. In 2019, around 4.5 billion passengers travelled through the air.
To try to reduce the impact that flights have on the environment, hydrogen trials have been taking place in planes since 2020.
One of the most successful trials to date is from a German company called H2FLY. The HY4 is the first hydrogen-electric passenger plane, showing that this technology could be used in the future aviation industry.
Railways
Hydrogen is also being considered for the UK railway system. Trains currently use diesel fuel to operate, so the options are to replace this with hydrogen or electrify the railways.
The Railway Industry Association estimates the cost to electrify the rail network would range from £750,000 to £1 million per kilometre of track, totalling around £9 billion in total.
In 2018, Germany introduced the world’s first passenger train fuelled by a hydrogen fuel cell, inspiring multiple other projects around the world including in the UK, California, Ireland, Italy and the Middle East.
The University of Birmingham has been working on a game-changing hydrogen project, known as HydroFLEX, which will help to decarbonise the rail network in the UK. Bringing together minds from academia, industry and government, the project could revolutionise the UK railway as we know it.
How to make hydrogen gas
Hydrogen is a naturally occurring element found in water, as the “H” in “H20”. However, it must be separated using electrolysis before it can be used as a gas. Hydrogen can also be produced from methane gas using steam reformation.
Depending on the production method and the source of electricity, hydrogen is categorised and given a reference colour.
It is important to note that whilst production methods vary to create the different ‘colour’ categories, often a more important consideration in the quest for net zero, is assessing the amount of carbon released into the atmosphere.
Green - Green hydrogen is produced using zero-carbon electricity which comes from wind or solar power. Using electrolysis, hydrogen can be extracted from water. This is the most environmentally friendly method to produce hydrogen.
Blue hydrogen - this production method uses steam methane reformation to produce hydrogen from methane gas. Natural gas is reacted with steam to produce hydrogen.
During this process, the carbon is removed and stored underground, instead of being released into the atmosphere. This is called carbon capture, and it is estimated by the University of Cambridge that carbon dioxide can be stored underground for ten times the length needed to avoid climatic impact. This means that all the carbon emissions that would have been released into the atmosphere by burning the natural gas are stored safely, until there is more capacity to create green hydrogen.
Grey hydrogen - Currently, most hydrogen produced is grey. This comes from natural gas using steam methane reformation, like blue hydrogen, but without capturing the carbon.
These three colours are the most common types of hydrogen widely discussed, but the rainbow continues with pink, yellow, turquoise, brown and white.
Benefits of hydrogen
Net zero carbon - The primary benefit of using hydrogen to replace natural gas is its potential to reduce global carbon emissions on the path to net zero.
Jobs and economy - The UK government estimates that replacing methane with hydrogen will result in the creation of over 12,000 jobs by 2030, increasing to 100,000 jobs by 2050, hugely boosting the economic growth and skill set of the UK.
Ease of transition - The UK has one of the most advanced gas networks in the world, operating since the 1950s. The network is already 80 percent developed for hydrogen, and experts from the gas networks in the UK have concluded that hydrogen could be blended into the existing network with ease. The UK Government announced in December 2023 that up to 20% hydrogen could be blended into the UK gas networks by the end of 2024. Blending just 20 percent hydrogen into today's network could reduce emissions by six million tonnes, equivalent to taking 2.5 million cars off the road.
Lack of suitable alternatives in manufacturing - Products like cement, ceramics, glass, paper and steel necessitate temperatures surpassing the capacity of electricity or requiring exposure to an open flame. At the moment, there is no alternative to gas that would be sufficient for manufacturing these materials.
Hydrogen and biomethane
When discussing the topic of more sustainable fuels, biomethane consistently emerges as a contender. This eco-friendly gas, also recognised as biogas, derives from the decomposition of organic materials such as manure, food waste and flawed crops.
This type of gas could be distributed similarly to hydrogen into the gas network, providing heat for homes and fuel for transport. It can also be generated on a small scale in your own home.
Role in net zero
Trials happening across the world will be key to determining the role that hydrogen will play in a net zero society, ensuring decision making is based on data and gaining consumer trust in the process.
The H100 trial in Fife is one such trial. This project, being undertaken by gas network SGN, will provide the world’s first green hydrogen to over 300 homes on the Fife coast.
Summary
The UK has a long history with hydrogen and it could help reduce reliance on fossil fuels. It could also help meet the net zero goals of the Paris Agreement.
With its capacity to be a clean alternative to methane gas, hydrogen not only aligns with the UK’s net zero ambitions but also promises economic growth, job creation and a smooth transition within existing infrastructure.
Hydrogen has its challenges; the main one is that to be a carbon-free fuel, it must be made using zero-carbon electricity or supported by carbon capture, which is still in the early stages in the UK.
As hydrogen emerges as a promising contender, the urgency for government decisions regarding its widespread adoption becomes evident.
