Clean energy: seizing the power of green hydrogen
Surging fossil fuel prices have made green hydrogen a viable option, with profound implications for energy infrastructure
The war in Ukraine has super-charged the price of natural gas, bringing serious challenges for governments, businesses and individuals. As nations look to the future of their energy supplies, is it time to get serious about green hydrogen?
Green hydrogen is produced by electrolysis, powered by renewable energy. Electrolysis breaks water down into oxygen and hydrogen, which can then be used as a clean energy source. What’s more, burning hydrogen produces water and no other emissions.
The renewable fuel source is now cheaper than natural gas, so it may be time to seriously consider its role in the future energy mix. For some in the energy industry, green hydrogen holds vast potential, not just in advancing the global energy transition and energy security but also contributing to climate goals and the race to net zero.
By 2050, 12% of the world’s energy needs could come from hydrogen, according to the International Renewable Energy Agency. Green hydrogen has the potential to rewrite the energy infrastructure map for the net zero age, since energy production could shift to those nations that have both excess low-carbon energy and invest heavily in green hydrogen infrastructure.
“We’re seeing a strong increase in the number of global hydrogen strategies, many centred around green hydrogen,” explains Dr Graham Cooley, CEO of ITM Power, which makes hydrogen technology like electrolysers. There are profound implications for the global energy market, Cooley says.
“As we are seeing today, weaponising energy supply means energy security for almost all nations has risen to the top of agendas. Green hydrogen is the only zero-carbon energy gas and can be produced anywhere that has renewable power resources.”
There’s already significant interest in hydrogen. According to the Hydrogen Council, a private sector-led organisation backed by many traditional energy firms, 520 projects and more than 90GW of capacity have been earmarked worldwide, amounting to $160bn in investment, though this is for all forms of renewable and low-carbon hydrogen, including hydrogen created from fossil fuels with carbon capture and sequestration. Funds are being allocated across the world, from Saudi Arabia to Australia and from Japan to Germany.
“We are starting to see offshore and onshore wind developers bringing forward green hydrogen projects at scale. But these green hydrogen suppliers need to be confident that they have customers who will offer them a route to market,” says Clare Lavelle, energy consultancy leader at Arup.
A nascent industry
The hydrogen sector is still in an early stage of development, with limited infrastructure and challenges around scaled-up deployment. The upfront technology development and cost required is significant, as is the investment in bulk plant, storage and distribution, as well as related safety and security elements.
What’s more, producing green hydrogen from water is an energy-intensive process. Where possible, businesses and communities are better off using the electricity generated from renewables directly, whether it’s for heating via heat pumps or transport on electric vehicles. Using electricity from renewable sources to create and then burn hydrogen is roughly 30% efficient. In comparison, batteries as an energy store are more than 80% efficient.
“More evidence and research is needed to understand the optimal net-zero energy system and the balance of gas and electrons that can deliver an economic transition,” says Lavelle.
However, in energy-intensive industries like chemical and steel production where high-grade heat is needed, green hydrogen could replace coking coal to provide a greener alternative. In some transport situations where battery technology will struggle, such as in heavy goods vehicles or shipping, hydrogen also comes into its own.
Hydrogen can also be used to produce ammonia via a well-known process called Haber-Bosch. Ammonia is a vital chemical used to produce fertilisers, an area of concern while supplies from Ukraine and Russia are in question.
Green ammonia can also be used as a fuel source. It’s easier to transport than hydrogen and is more energy intensive as a fuel, with the global shipping industry looking to green ammonia to power boats.
“Hydrogen is an excellent energy vector that has applications in a variety of sectors and can be produced when there is excess or cheap electricity and stored as ammonia,” says Ben Sawford, vice president at KBR Global Sustainability Advisory. “It can then be utilised at another time, when demand is high and supply is low. Additionally, cogeneration in nuclear power plants offers massive advantages not seen with other technologies.”
A question of cogeneration
What is cogeneration? This is where excess heat, electricity or other forms of energy are used to generate another form of power, preferably one that can be stored or used immediately.
For example, typically 65% of the energy generated by nuclear power plants is lost as waste heat, which is extremely inefficient if it isn’t used. New advanced nuclear technologies are being developed that will be able to operate at significantly higher temperatures than existing plants, which could be advantageous when it comes to generating hydrogen.
“The process can utilise these high temperatures alongside electrolysis to produce hydrogen,” says Neil Leggatt, group business manager for nuclear at Frazer-Nash Consultancy. He notes that steam electrolysis using nuclear heat and electricity could produce hydrogen using 35% less electricity, with an overall efficiency of about 50%.
There are plans to locate hydrogen plants next to nuclear reactors to provide cogeneration. There are also efforts to locate green hydrogen plants alongside other renewables such as wind farms, so that when excess electricity is generated it can be turned into another source of energy.
The complexity of the energy transition and future energy mix demands a joined-up approach in government policy and energy security. A mix of low-carbon energy streams and infrastructure will be needed to provide a consistent supply. Hydrogen production could ensure less energy is wasted and help tackle critical, yet energy-intensive industries that have traditionally used fossil fuels.
What’s more, nations with abundant solar or wind power that produce excess power beyond their own demands will be able to export renewable power by shipping green hydrogen or ammonia to where it’s needed.
“Renewable-rich nations will increasingly have the opportunity to supply nations that do not meet their own energy demands,” says Lavelle, pointing to collaboration between Scotland and Germany and between Japan and Australia.
The future looks bright for green hydrogen. However, careful and considered deployment will be crucial if it is to be truly valued in the future energy mix.