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- What can we use hydrogen for? It can be used for heat and power, as part of the production of other chemicals, or to store energy for later use
- Supporting renewable energy Hydrogen can act as an energy store as a backup for renewable sources like solar power or wind power
- Using hydrogen safely Preventing leaks, adding a scent, transporting it carefully and controlled burning can help minimise risks
What can we use hydrogen for?
Hydrogen is valuable because it is an energy carrier A substance that contains energy which can be later converted into other forms for use that can be used in many different ways:
1. As a replacement for fossil fuels in many areas
2. As a feedstock A raw material needed to fuel a machine or industrial process for industry and chemicals
3. As a way of supporting renewable power and heat
Home heating and cooking explores the possibility of using hydrogen in our homes, and how that would require adapting our ovens, stoves and boilers.
Travel and transport covers hydrogen cars as well as a range of other vehicles, including forklifts, buses, trains and trucks.
Business and industry explores how most of the hydrogen produced today is used in industry as a feedstock to make products like fertilisers and metals.
Supporting renewable energy
Each year, the amount of renewable energy Energy from a source that can be renewed or does not deplete when used (such as wind power, biomass Plant or animal matter that can be used to generate energy and solar power) used globally grows. While weather-based energy sources are clean and sustainable, we have no control over when they provide power – they only work when the wind blows or the sun shines. Sometimes the amount of renewable energy available does not match demand, so other energy sources such as natural gas are required to make up the difference. Along with batteries or hydroelectric dams, hydrogen could change this by storing up surplus energy for when it is needed. The gas can be stored in pressurised containers, or underground given suitable geology such as salt caverns.
One example of storing energy as hydrogen is a process called power-to-gas.
Just like with any energy conversion, there will be some losses involved in the power-to-gas process. Nevertheless, hydrogen has the potential to be a cheaper energy store than batteries. Examples of power-to-gas include GRHYD, a project in the Dunkirk region run by energy company ENGIE and supported by the French Government; and German project Energiepark Mainz.
Using hydrogen safely
Hydrogen is flammable and ignites easily, which carries safety risks. Hydrogen gas has unique physical and chemical properties; understanding the way it behaves in different situations is vital so it can be used safely. Organisations such as the UK Health and Safety Executive and Hydrogen Europe, as well as private companies, are conducting research into the operational risks of using hydrogen for new applications like heat and transport. When using a new energy source, it is important to learn as much as possible about any potential risks and how to manage them – our use of natural gas has progressed in the same way.
Hydrogen is a non-toxic gas with no colour, taste or smell. It burns with a very pale blue flame and does not produce hot ash or smoke, so it is difficult to detect when it is burning or leaking. One option is to add a suitable strong-smelling chemical called an odorant A substance that gives something a smell to the gas mix so that it is easy to detect – an odorant is what gives natural gas its distinctive smell. However, odorants can contaminate technologies, such as fuel cells A device that produces electricity from a chemical reaction between oxygen and another substance , which require pure hydrogen gas.
Hydrogen gas has a lower density than air, which means that if it leaks, it will quickly float away. However, as with other flammable gases, if the leak is indoors the gas could build up and cause a fire or explosion. Buildings using hydrogen should include suitable ventilation for pipes and boiler systems – rooms can also include one-way, mechanical ventilation which will allow any gas that builds up to escape. Infra-red sensors can be installed to detect leaks at the meter.