Although hydrogen is the most abundant element on earth paired with other elements to create our environment, hydrogen doesn’t naturally occur in its pure form. This means we have to generate it.
Hydrogen can be used in multiple ways in multiple sectors, so it can be quite confusing. Let’s try and clarify.
It all starts with the production of hydrogen. Hydrogen can be produced from methane or by electrolysis of water. Electrolysis means that electricity is run through water (H2O) to separate the hydrogen and oxygen atoms from each other. Electrolysis in itself does not produce any CO2 and it can be done with a range of energy sources. When combined with renewable energies, the process of electrolysis is zero emission from start to finish.
Once produced, electricity and heat can be generated from hydrogen in various ways, such as the fuel cell, hydrogen boiler, as a feedstock for chemicals or in gas turbines. To illustrate with a simple example: in cars, hydrogen is combined with oxygen from the air to produce electricity in a fuel cell, with water as the only by-product. One of the most important advantages of hydrogen as a fuel is that it can be used without producing carbon emissions, which makes it environmentally friendly.
Because hydrogen can be stored as a gas, it’s easy to transport so it can be used wherever its power is needed. This means it can be used to store excess renewable energy over longer periods of time. Allowing consumers and industries to use renewable energy created at any time, even when there is no wind or sun.
A fuel cell is any device that generates electricity by means of a chemical reaction. Used in a fuel cell, hydrogen combines with oxygen from air to produce electricity, with water as the only by-product. The main difference between a battery and a fuel cell is that batteries store energy, while the fuel cell generates it.
There are many types of fuel cells for different uses. Small fuel cells can power laptop computers or mobile phones. Large fuel cells can provide electricity for emergency power to hospitals or to buildings that are not connected to the power grid.
You may have heard about the many colours of hydrogen. Just like other energy carries, for example electricity, hydrogen is as clean as the primary source and the method of production.
Grey hydrogen is produced using fossil fuels such as natural gas. Blue hydrogen is generated using fossil-based sources combined with carbon capture, utilisation and storage (CCUS), which is a way to capture the carbon dioxide that would normally be emitted into the atmosphere and store it or utilise it, thereby reducing the impact of those emissions. Green hydrogen is generated from renewable sources like wind and solar power. Both blue and green are considered low-carbon hydrogen, that will help to achieve our climate targets.
Hydrogen has long been recognised as a great energy solution; but until now the cost to produce it has been too high for industry and governments to invest in it on a mass scale – put simply, affordability is important to everyone and there was always a cheaper option. Today, however, the cost of technologies has gone down and the imperative to find cleantech solutions to tackle the urgent climate crisis has put hydrogen back on the map. Hydrogen is now ready for massive scale-up.
Our energy system is ready for a revolution, to provide clean, safe, affordable energy across sectors and regions around the world for generations to come. Putting hydrogen at the heart of transportation will transform mobility for the 21st century, getting us all from A to B in a more sustainable way. And injecting hydrogen solutions into other energy-hungry industries, such as steelmaking, industrial heating and manufacturing will allow mankind to continue making the things we all love while decreasing its toll on the climate.
Hydrogen is the tiny, versatile molecule that – harnessed for its immense power – can become a big hitter in the global clean energy space.