Hydrogen is just one of many clean technologies that could help the world achieve net zero emissions. But what do we really know about its potential benefits and its possible drawbacks? This article dives deeper into hydrogen as a source of clean energy and explores its potential, as well as the challenges to its wider use.
What is hydrogen?
Hydrogen is the lightest and most abundant element in the universe, making up about 75% of all normal matter. The name “hydrogen” comes from the Greek words “hydro” (water) and “genes” (forming) because hydrogen is the main component of water (H2O).
Hydrogen is an energy carrier, meaning that it can be used to store, move, and deliver energy produced from other sources. Unlike other energy carriers, such as methane, hydrogen does not produce any carbon dioxide when used for particular applications, and it is this quality which makes it a promising clean energy source for the future.
How can hydrogen be used to power the world?
Hydrogen is a versatile energy carrier that can be used in a variety of ways, just like the (heavily polluting) methane. It can be used to produce electricity in power stations, heat homes, and power vehicles. When used in a fuel cell, hydrogen produces no greenhouse gases, only water vapour.
One critical application of hydrogen is its use as an energy storage medium for renewable energy production. When solar and wind power produce more electricity than needed, the excess can be used to split water into hydrogen and oxygen. The hydrogen can then be stored and used to generate electricity when renewable energy production falls.
Today, hydrogen is most commonly used in petroleum refining and fertilizer production, but transportation and utilities are emerging markets with significant potential.
An added benefit of hydrogen is that it can be used in existing infrastructure. For example, hydrogen can be used to fuel gas-powered vehicles or homes with minimal modifications, making it a more affordable and scalable option than other clean energy technologies.
What are the different types of hydrogen?
Hydrogen can be produced in several ways using a number of different resources. To distinguish it, hydrogen is typically categorised with a specific colour, the different types are:
Other and less common types include:
What are the challenges of using hydrogen as a fuel?
Despite the many positive reasons for harnessing hydrogen, it is also important to understand the challenges. Firstly, hydrogen continues to be expensive to produce, and in many instances it is created through the use of fossil fuels, which release greenhouse gases, therefore negating the clean-energy benefits.
Secondly, hydrogen is difficult to store and transport as it has a ‘low volumetric energy density’ compared to other gases, such as natural gas. This means it takes up significantly more space, which can add substantially to the costs of storage and transportation.
Lastly, depending on how hydrogen is used, it isn’t entirely emission free. When used in an application such as a fuel cell, the only output is water vapour, however, when used in combustion, a by-product is nitrogen oxide (NOx), which has a warming potential 265 times that of carbon dioxide.
What is the future of hydrogen power?
The International Energy Agency (IEA), which has described hydrogen as “a key pillar of decarbonisation for industry”, highlights that there are almost 1,500 low-carbon hydrogen projects currently underway. The green hydrogen (produced from renewable energy sources) market alone, which was valued at $676 million in 2022, is projected to reach $7.3 billion by 2027.
Building on this, the global research and consultancy, Wood Mackenzie, estimates that low-carbon hydrogen could constitute 7% of global final energy demand by 2050.
Furthermore, the market is expected to continue accelerating thanks to efficiency improvements in production and low-carbon incentives such as the US’s Inflation Reduction Act (IRA) and the EU’s Net Zero Industry Act.
In conclusion
Despite the challenges outlined above, it is clear that hydrogen does have the potential to play a significant role in the future of energy. Whilst it is important to recognise that it is not the miracle solution, it is a clean, versatile, and – most crucially – a scalable energy carrier that could help us reduce our reliance on fossil fuels, leading us to a cleaner and greener future.
