Hydrogen energy is not a new concept, but it is certainly tipped to be the future of the global energy industry, so let’s go back to basics and answer the question of ‘What is hydrogen energy?’
Hydrogen itself is a clean fuel that when used, only produces water as a side product. This makes it extremely attractive to big energy companies, governments and organisations who are looking to achieve a net zero carbon status.
When we consider the question ‘What is hydrogen energy’, the answer is actually quite simple: Hydrogen is the simplest element and it is an energy carrier that can be utilised to store, move and deliver energy, and its power can be harnessed through various methods.
Hydrogen occurs abundantly on earth and can be combined with other elements. When combined with oxygen it forms water (H2O) and when combined with carbon it produces different hydrocarbons that can be found in natural gas, coal, and petroleum. There are two types of hydrogen energy production – green hydrogen and blue hydrogen. We will cover what these are below.
Read on to find out more about how hydrogen is already being used, why hydrogen is important as a future clean energy source and how the world is tapping into the vast potential of hydrogen energy.
How is hydrogen fuel produced?
Interestingly, hydrogen fuel can be produced through several methods. Blue hydrogen is produced from non-renewable energy sources, whereas green hydrogen is produced by using renewable electricity sources to power an electrolyser that splits the hydrogen from water molecules.
- – Thermal processes: Thermal processes for producing hydrogen involves steam reforming, a very high-temperature process where steam reacts with hydrocarbon fuel to produce hydrogen. Currently, about 95% of all hydrogen is produced from steam reforming of natural gas.
- – Electrolytic processes: This process uses an electrolyser to separate water into oxygen and hydrogen. An electrolyser acts much like a fuel cell in reverse.
- – Solar-driven processes: In this process, light is used as the catalyst for hydrogen production and there are various methods including photobiological, photoelectrochemical, and solar thermochemical. Photobiological processes use the photosynthetic activity of bacteria and green algae, photoelectrochemical processes use specialised semiconductors to separate water, and solar thermochemical hydrogen production uses concentrated solar power to split water.
- – Biological processes: These processes use microbes such as bacteria and microalgae. In microbial biomass conversion microbes break down organic matter like biomass or wastewater to produce hydrogen.
What is hydrogen energy already being used for?
One of the most relatable and exciting uses of hydrogen energy at the moment is in cars and there are already many cars in the marketplace that operate on hydrogen fuel cells. Of course, having the infrastructure in place to support vehicles like this is crucial.
Japan is leading the way with this, with nearly 100 public hydrogen refuelling stations in operation across the country where you can fill up quickly just as you would with petrol or diesel.
Germany is in close second, with approximately 80 of these refuelling hydrogen stations in operation and America comes in third place with around 42 stations.
What is hydrogen energy going to look like in the future?
To look into the future of the energy industry, let’s first look at the past.
A fuel is a chemical that can be ‘burnt’ to provide useful energy. When burnt, the chemical bonds between the elements in the fuel are broken meaning these elements then chemically combine with oxygen, usually in the air.
Traditionally we’ve used natural gas as the energy source to heat our homes and businesses and to generate electricity. This is because it is a readily available resource that is cost-effective and a cleaner alternative to coal. When natural gas is burnt is provides heat energy, but it also produces the waste product carbon dioxide which can contribute to climate change.
The benefit of using hydrogen instead of natural gas is that it does not release carbon dioxide, its only ‘waste’ product is water.
While this is definitely an exciting new era for the energy industry, the movement to hydrogen energy cannot happen overnight. For hydrogen to be a viable alternative, it needs to be produced at a large scale, in an economical way and which creates some significant challenges to the world’s infrastructure.
The good news is that hydrogen can be transported through existing gas pipelines, which will minimise disruption and reduce the amount of expensive infrastructure required to create a new network. The production of hydrogen-energy versions of cooking and heating appliances is also already emerging.
One of the reasons why hydrogen is so useful as an energy fuel is because it has a high energy content per unit of weight – which means it can be used as a rocket fuel!
A recent report from the IEA – The Future of Hydrogen: Seizing Today’s Opportunities – has found that clean hydrogen is currently receiving strong support from governments and businesses around the world.
“Hydrogen is today enjoying unprecedented momentum, driven by governments that both import and export energy, as well as the renewables industry, electricity and gas utilities, automakers, oil and gas companies, major technology firms and big cities,” Dr Birol said in the report. “The world should not miss this unique chance to make hydrogen an important part of our clean and secure energy future.”
The IEA report specifies four areas where actions today will lay the foundations for the growth of a global clean hydrogen industry:
- ‘Making industrial ports the nerve centres for scaling up the use of clean hydrogen
- Building on existing infrastructure, such as natural gas pipelines
- Expanding the use of hydrogen in transport by using it to power cars, trucks and buses that run on key routes
- Launching the hydrogen trade’s first international shipping routes.’