According to the IEA Electricity Market Report of Feb 2023, by 2025 world electricity demand will increase to 2,500 TWh above 2022 levels, meaning that over the next three years the annual increase in electricity consumption will be approximately equivalent to that of Germany and the United
Kingdom combined. A sobering thought!
Renewables and nuclear energy will dominate the growth of global electricity supply over this period, together meeting on average more than 90% of the additional demand, with their share of the power
generation mix rising from the 2022 level of 29% to 35% in 2025. China is set to meet more than 45% of renewables generation, and the EU 15%.
The difficulty is that, while being an excellent medium for renewable energy storage, hydrogen itself is
tricky to store.
This is because it has a low volumetric energy density compared with other gases — such as natural
gas — meaning it takes up much more space. Also, hydrogen has a boiling point close to absolute zero
and so in its liquid form requires cryogenic storage. Furthermore, under certain conditions, it can
cause cracks in metals, particularly in iron and high strength steel. This is known as ‘hydrogen embrittlement’. However it’s a potential issue that can be resolved.
2. power generated on windy or sunny days into hydrogen, the gas can store renewable energy that can
then be deployed at times of peak demand as a clean fuel source for power generation.
Second, hydrogen can replace fossil fuels to decarbonise sectors where electrification alone isn’t
adequate, such as domestic heating, industry, shipping and aviation. As an energy source it is very
scalable.
The difficulty is that, while being an excellent medium for renewable energy storage, hydrogen itself is
tricky to store.
This is because it has a low volumetric energy density compared with other gases — such as natural
gas — meaning it takes up much more space. Also, hydrogen has a boiling point close to absolute zero
and so in its liquid form requires cryogenic storage. Furthermore, under certain conditions, it can
cause cracks in metals, particularly in iron and high strength steel. This is known as ‘hydrogen
embrittlement’. However it’s a potential issue that can be resolved.
Here are four hydrogen storage solutions that could help address these challenges.
1. Liquefied hydrogen
As well as being stored in its gaseous state, hydrogen can also be stored as a liquid. In fact the space
industry has been using liquefied hydrogen to fuel rockets for many years.
But liquid hydrogen storage is technically complex and thus quite costly. It has to be cooled to -253°C
and stored in insulated tanks to maintain the low temperature and minimise evaporation. This requires
complex and expensive plant which has limited the use of liquefied hydrogen.
The semiconductor chip industry is also a major user of liquefied hydrogen. However, with the
proliferation of renewable hydrogen supply and demand, greater economies of scale will make
liquefaction a more viable storage and transport option in the future.
2. Compressed hydrogen storage
Like any gas, hydrogen can also be compressed and stored in tanks, and then used as needed. However
its volume is much larger than that of other hydrocarbons relative to their weight — nearly four times
greater than natural gas. So for practical handling purposes, hydrogen needs to be compressed. For
example, fuel-cell powered cars run on compressed hydrogen contained in highly pressurised
containers.
If an application requires hydrogen volume to be reduced further than attainable by compression, it
can be liquefied. The two techniques — compression and liquefaction — can also be combined.
Hydrogen’s low energy density, high volume, and need for cryogenic storage are some of the biggest
barriers to its adoption. This is especially true for use in transportation, where a balance must be
struck between passenger space and range.
3. Geological hydrogen storage
The storage of hydrogen underground, both onshore and sub-sea in caverns, salt domes, depleted oil
and gas fields, and aquifers (porous rock or sediment saturated with groundwater) is fast-becoming a
serious contender for hydrogen storage at scale. In fact gas storage in salt caverns is a long-established
method, making the technology easy to adapt.
5. References
1. IEA – Demonstrating the technical, economic and social viability of underground hydrogen
storage
2. Cedigaz – Cedigaz Insights: Underground Gas Storage in the World 2018
3. Journal of Energy Storage – Volume 53, Sep 2022: Does the United Kingdom have sufficient
geological storage capacity to support a hydrogen economy?
4. Wood Mackenzie – Global Project Tracker
5. Linde Hydrogen – Expert insights 2022: Hydrogen supply in caverns (PDF download
6. Engie – H2 in the underground: Are salt caverns the future of hydrogen storage?
7. Storelectric – Hydrogen and integrated solutions
8. CNBC – An $11 trillion global hydrogen energy boom is coming. Here’s what could trigger it
Media Contact
Mark Howitt, CTO & Co-Founder
Storelectric Limited
11th Floor, 3 Piccadilly Place, Manchester, M1
3BN, United Kingdom
tel: +44 (0) 161 242 1151
web: storelectric.com
Publisher Contact
Tony Wood, Editor
BXD
in: tonywoodbxd
web: bxdsystems.com