Hydrogen is building momentum as a key energy carrier in the global effort to reach net-zero CO₂ emissions by 2050.
In 2019, it rose to the top of the discussions between global leaders at the G20 summit in Japan. This event was supported by a comprehensive report from the International Energy Agency (IEA) that declared “unprecedented momentum” as hydrogen was “increasingly a staple of mainstream energy conversations in almost all regions.”
In total, there were over 50 policies globally supporting investment in hydrogen by mid-2019. These included initiatives under way in 11 countries from the G20 and the EU, plus the U.S. state of California.
The momentum that built up in 2019 has continued into 2020, with the first quarter alone seeing German chancellor Angela Merkel highlighting the importance of hydrogen for decarbonising her country’s steel sector and the UK starting its first trial of injecting hydrogen into its gas grid for domestic heating.
Meanwhile, the European Commission’s new Industrial Strategy contains plans to establish a Clean Hydrogen Alliance to accelerate the decarbonisation of industry, while maintaining its competitiveness.
An almost symbiotic relationship is emerging between hydrogen and renewables. As wind turbines and solar PV panels become cheaper, so does the cost of producing green hydrogen from renewables through electrolysis.
At the same time, the IEA points out that as renewables begin to account for a high proportion of the energy mix, their variability poses a challenge. This means the need for large-scale energy storage to smooth out differences between supply and demand becomes more pressing.
Hydrogen offers the potential for energy storage on a much greater scale than the battery solutions currently being used to provide flexibility to the grids.
This is a particular advantage when there are large seasonal variations in the level of electricity generated by renewables and can help capture energy that might otherwise be wasted.
For example, hydrogen storage could be used to capture the excess electricity generated by offshore windfarms during the North Sea’s fierce winter winds, or it could take advantage of the longer summer days and additional electricity generated by solar PV farms in regions of the US such as Utah.
Storing renewable energy in the form of hydrogen may also have a double positive spill over effect: while it allows for the use of the existing gas infrastructure as an energy sink, it furthers the decarbonisation of those same assets.
The Hydrogen Council estimates that by 2030, 250 to 300 terawatt hours (TWh) of surplus renewable electricity could be stored in the form of hydrogen – that’s more than the entire annual amount of electricity generated by many major advanced economies, including Australia and Italy.
In addition to this theoretical storage potential, independent research commissioned by the Japanese government shows that projected demand for green hydrogen as a fuel, rather than just as a form of storage, could require up to 16TWh of renewable power generation by 2050.
Using hydrogen as an effective form of renewable power storage relies on the ability to convert the gas back into electricity.
This requires power plants capable of using hydrogen fuel and generating a steady supply of electricity. As well as realising the stored hydrogen’s potential, these plants could help stabilise grids where there are high proportions of variable renewables in the system.
The Hydrogen Council claims that more than 200TWh could be generated from hydrogen in large power plants.
Japan’s Basic Hydrogen Strategy targets commercialised hydrogen power generation by 2030, and in response Mitsubishi Hitachi Power Systems (MHPS) took the first step in 2018 by developing and successfully testing a gas turbine combustor capable of utilising a fuel that is 70% liquefied natural gas (LNG) and 30% hydrogen.
The advantage of this solution is that existing power plants can be renewed to low-carbon or CO₂-free power generation just by converting burners and associated equipment. MHPS is now working with Vattenfall to deploy this technology at its Magnum power plant in the Netherlands. This project aims to convert one of the three existing MHPS units, which house M701F gas turbines (440MW/unit), to be 100% hydrogen-firing by 2025.
On a smaller scale, hydrogen can also be used as a distributed energy source via solid oxide fuel cell (SOFC) technology. SOFCs developed by MHPS can replace diesel generators as cleaner power backups in places such as commercial buildings, using either hydrogen or natural gas to generate both electricity and heat.
Scaling Hydrogen to Go Green
Production of green hydrogen from renewables offers a tantalising solution to the storage challenges of power sources such as wind and solar. Western states in the US such a California and Utah are already creating green hydrogen and plan to scale it over the coming years.
However, not all regions and industries are ready to make the transition directly to green hydrogen. Analysis by McKinsey on behalf of the Hydrogen Council reveals that even though the costs of producing renewable green hydrogen will fall 60% in the next decade, it will take until the mid-to late 2030s before it can rival conventional “gray” methods of hydrogen production from coal and natural gas.
Blue hydrogen, on the other hand, is much more likely to be commercially viable in the near future. This type of hydrogen uses conventional carbon-intensive methods of production, but couples it with CCUS technology to ensure CO2 emissions from the production process are not released into the atmosphere.
McKinsey’s analysis predicts that with the addition of carbon pricing, blue hydrogen will be cost competitive with gray hydrogen by 2030. Dependent on local natural gas prices, blue hydrogen may already be cheaper than gray hydrogen in some parts of the world.
There are 19 CCUS plants operational around the world today, with a further 32 planned or under construction. The largest facility is in Texas and uses Mitsubishi Heavy Industries Engineering (MHIENG) technology.
CCUS represents the best hope for scaling up hydrogen production in the short-to medium-term. Using blue hydrogen to establish supply chains and growth in demand for the gas will ensure that by the time green hydrogen projects become commercially viable, they have a ready-made market to sell into. Blue gets us to green.