Inside Green Innovation: Progress Report - Fourth Edition highlights:
- The recent dramatic innovation surge in hydrogen storage technologies appears to have reached a peak.
- Further innovation combined with appropriate sector support is required to fully utilize hydrogen as a clean and sustainable energy and feedstock source.
- Some sectors are seeing increased traction with aviation and shipping being areas of current focus for hydrogen storage innovation; encouraged by green initiatives to reduce the carbon footprint of these energy intensive modes of transport.
- South Korea has dominated innovation in hydrogen storage technologies since 2019, followed by Japan and Europe.
- Hyundai is a major contributor to the number of global patent filings, backed by the company’s ambition is to apply hydrogen energy to all areas of life and industry to enable a worldwide hydrogen society by 2040.
Hydrogen could play a key role in the move towards greener energy worldwide. Improving how companies produce and store hydrogen is essential for reducing carbon emissions across a range of sectors, such as energy systems, chemical production, and transportation. According to Hydrogen Insights 2024, a report published by the Hydrogen Council (a global initiative of 140 investment companies who aim to develop the hydrogen economy), and McKinsey & Company (a management consulting firm), the global hydrogen project pipeline has increased 7-fold between 2020-2024, with more than 1,500 hydrogen project proposals announced globally, with USD 370bn of direct investment into hydrogen value chains throughout 2030. Europe continues to have the largest number of projects (617), maintaining its status as the global leader, followed by North America (280). Japan and South Korea have shown the highest relative growth in investments of about 130%, while India demonstrates growth of 110%. In the recent 2024 Autumn budget delivered by Chancellor Rachel Reeves, the UK government confirmed £2bn in funding for 11 electrolytic hydrogen production projects across the country, with £413m of private capital being invested upfront between 2024-2026. These projects have a total capacity of 125MW and are said to be among the first commercial-scale projects anywhere in the world.
Evidently, there is a global interest in the development of hydrogen technologies. However, there are several important challenges in producing and using hydrogen safely, affordably and efficiently, while preserving hydrogen purity. Hydrogen producers must overcome these challenges for hydrogen to help reduce global emissions and contribute significantly to reaching net zero. Realising the potential of hydrogen, especially as a medium for energy storage, requires new and efficient technologies for its production, transportation, and storage. The latter are challenging because hydrogen – while having the highest energy density per mass of any fuel – has the lowest energy density per unit volume due to its low density at room temperature. Organisations globally are developing innovative hydrogen systems to address these issues and – because of its high potential as part of the worldwide shift to green energy – this field is poised for promising advances in materials science, nanotechnology and other related fields. Indeed, this shift towards green energy is illustrated in the patent filing data, which shows that patent filings for hydrogen storage technologies began in the late-1990s, likely as a response to the United Nations Framework Convention on Climate Change in 1992 and subsequently the Kyoto Protocol in 1998 which were precursors to the Paris Agreement 2015.
Global patent filing trend
Hydrogen storage technologies fall broadly into three categories:
- Compression
- Liquefaction
- Material-based storage.
Well-established technologies for hydrogen gas storage are tanks and vessels for compressed or liquefied hydrogen gas, and salt caverns for compressed hydrogen gas. The cost of storing hydrogen in tanks and vessels is about £2.00 per kilogram, whereas the cost of storing compressed gas hydrogen in salt caverns is less than £0.50 per kilogram (kg). However, there are only four designated hydrogen storage salt caverns in the world today, three in the USA and one in the UK. Therefore, it’s an imperative to develop hydrogen storage facilities and techniques that provide increased capacity combined with low cost.
Figure 1: Thirty-year trend (1993-2022) - global priority filings – hydrogen production and storage
(Priority filing = the first time a patent application for a unique invention has been filed (the first filing))
Patent applications for hydrogen storage technologies follow a strikingly similar trend to those for hydrogen production technologies, which we reported on in our 2023 edition of the Inside Green Innovation: Progress Report. This trend is predictable, as both hydrogen storage and production improvements are required to get a still-embryonic hydrogen economy moving.
The annual amount of new patent applications related to hydrogen storage filings began to increase in the 1990’s, reaching a first peak around 2000-2003. This comes slightly earlier than the peak in hydrogen production filings, which occurred in 2005.
The recent, unprecedented surge in patent filings for hydrogen storage began in 2019. This year we report for the first time that the surge has come to a rather abrupt stop. New patent applications in the most recent data related to both hydrogen production and hydrogen storage have suddenly plateaued. Whether this is a blip associated with the recent, difficult economic conditions limiting investment in an early-stage industry – or an early sign of a longer lasting loss of confidence – remains to be seen.
The 2015 Paris Agreement coincides with the start of the recent surge in hydrogen storage patent application filings. No doubt, this international treaty acted as a catalyst for developing clean technologies on an industrial scale. However, the agreement has been subject to some turbulence. For example, in November 2020, the US withdrew from the Paris Agreement and were later readmitted in 2021. This uncertainty may go some way to explaining the plateau in applications in 2021 and 2022.
Despite the current trend in patent data, the hydrogen storage technology market is expected to expand more than 10-fold in value by 2028. A key motivator for the future development of this technology is the use of hydrogen storage in parallel with renewable power generation. The goal is to use hydrogen to store electrical energy as chemical energy, when electricity produced through renewable energy sources exceeds demand. It will be interesting to see whether, as appears likely, different storage technology will evolve for different applications of hydrogen – whether as mass storage of renewable energy for use in transport in combination with fuel cells, or as a greener raw material in industry.
Patent applications by sector
During the first surge in patent applications related to hydrogen storage technologies between 1997 and 2007, innovations were balanced across the fields of chemistry, mechanical engineering, and electrical engineering. In contrast, the most recent surge in hydrogen storage innovations predominantly comes from the mechanical engineering sector.
Figure 2: Ten-year trend (2013-2022) - patent families by sector – hydrogen storage
While the quantity of patent filings does not necessarily equate to the quality of innovation – and, equally, a step-change in innovation can be masked by a low number of supporting filings – quantity, over time, tends to indicate the current focus of near to mid-term technology in a sector. As such, the growth of mechanical innovation could indicate that the recent surge in storage innovations focuses on optimising existing storage tanks and vessels rather than advancing new chemical storage technology. This may suggest a limit to the impact that the recent innovation will provide, due to the fundamental limitations of tank and vessel storage methods, particularly in transport. The present growth of innovations in the mechanical engineering sector fits with a general trend toward increasing demand and, therefore, scale of hydrogen production and storage. Consequently, organisations must solve new engineering challenges to efficiently and safely store and transport hydrogen as they produce it in larger volumes. While the current report focuses on hydrogen storage-based applications, a detailed review of trends in patent filings in hydrogen production is available in our 2023 edition of the Inside Green Innovation Report. Hydrogen storage innovation in the chemical sector has been consistent between 2005 and 2022, with innovations based on metallic elements for material-based hydrogen storage, fuel cells and apparatus for catalysis. In the mechanical engineering sector, focus has moved from developing fuel cells in 2005 to technologies for storage of liquefied and solidified gases. Finally, developments around electrical engineering in 2022 were focused on means of conversion to electrical energy, circuit arrangements for supplying and distributing electric power and systems for storing the electric energy produced by hydrogen.
Filings by territory
While the recent surge and slowdown is a global trend, the degree varies between territories.
Figure 3: Ten-year trend (2013-2022) - applications by territory – hydrogen storage
(Patent assignee = the owner of a patent/application, also known as the ‘applicant’ (for a patent application), patentee (for a granted patent), or proprietor.)
In Japan, the filings appear to fluctuate in two-year cycles between 2012 and 2022, with a general trend towards increased filings. Between 2013 and 2018, Japan dominated hydrogen storage related filings, which reflects Japan’s reputation as a world leader in policy making for a hydrogen economy. Under the Basic Hydrogen Strategy, Japan commercialised the world’s first fuel cell vehicles and increased the uptake and use of fuel cells in domestic households. In 2020 the Carbon Neutrality Declaration allocated approximately YEN 800bn (USD 5.5bn) to develop and commercialise hydrogen-related technologies. As we have covered in our past reports, there is regularly a link between stimulating government policy or tightening regulatory change and increasing levels of innovation. Following this trend, there is no doubt more exciting Japanese-led innovations will emerge in the near future. Since Japan invested in hydrogen as a fuel source and implemented the Basic Hydrogen Strategy, 26 other countries have developed their own national hydrogen strategies such as South Korea, which overtook Japan as the highest filer in 2019. The sharp increase in hydrogen-storage related patent filings in Korea coincides with the publication of Korea’s Hydrogen Economy Roadmap, which included goals to increase the number of hydrogen powered cars from 2000 in 2018 and to 6.2m in 2040. Korea also hopes to reach a capacity of 15 gigawatts (GW) of hydrogen by 2040.
While Korea now leads in patent filings for the hydrogen storage space, Europe is also establishing itself as a hub for innovation. Recently, the number of patent filings in Europe overtook those in Japan for the first time. Europe published its hydrogen roadmap in 2019 and claims that hydrogen could account for 24 percent of final energy demand by 2050, abating 50 mega tonnes (Mt) of CO2 emissions. While the US and China are currently lagging behind the other territories in the number of new annual patent applications related to hydrogen storage technologies, both countries have bucked the recent stagnation trend found in the currently leading territories. This is likely a result of the recent US Inflation Reduction Act, which incentivises investment in hydrogen technologies, and China’s expansion in hydrogen electrolyser facilities. In 2020, China accounted for less than 10 percent of global electrolyser capacity for hydrogen production, but has made great strides forward and now accounts for about half of the global capacity. As we have seen in previous years, innovation in these production technologies lends itself closely to innovation in storage.
New patent applications by applicant
Among the top filers of new patent applications, Toyota has established itself as one of them over the past ten years. However, more recently in 2021 and 2022, Hyundai and Bosch have the highest number of new patent applications per year.
Figure 4: Ten-year trend (2013-2022) - global priority filings of top five filers - hydrogen storage
(Patent family = A set of patent applications and/or granted patents across multiple countries that protect the same invention and were filed by a common applicant.)
In 2023, the European Patent Office (EOP) and the International Energy Agency (IEA) conducted a joint study into hydrogen innovation (including production, storage, and transport). In this study, Bosch was ranked in eleventh place among hydrogen innovators across all sectors. Bosch has established itself as a key player in this area and has been increasing the number of patent application filings related to hydrogen storage since 2013, making itself one of the top innovators in storage technologies. In 2022, Bosch’s hydrogen-related patent applications were predominantly in mechanical and electrical engineering and were generally related to tank systems for hydrogen-powered vehicles. Bosch has been researching and developing mobile fuel cells since 1990 and solid oxide fuel cells since 2004, and plans to invest 2.5m EUR in hydrogen fuel cell technology from 2021 to 2026. In a 2023 press release, Stefan Hartung, the Chief Executive of Bosch said, “Bosch is growing with hydrogen,” indicating that hydrogen will play a key role in Bosch’s future business strategy. We therefore expect the current trend in Bosch’s patent filings related to hydrogen storage to continue and are excited to see future development. Hyundai’s rapid rise to dominance in hydrogen storage innovation will come as no surprise after announcing its vision to popularise hydrogen by 2040. It aims to do this by developing the next generation of fuel cell systems, enabling the company to achieve a fuel cell electric vehicle price point by 2030 to match that of battery electric vehicles. Euisun Chung, the Chairman of Hyundai Motor Group said the Group’s ambition is to apply hydrogen energy to all areas of life and industry to enable a worldwide hydrogen society by 2040. These ambitions were reaffirmed by Hyundai when, in August 2024, it announced plans to provide energy and software solutions beyond mobility. This included developing megawatt-scale polymer electrolyte membrane (PEM) electrolyser manufacturing capabilities for green hydrogen production and showcasing its hydrogen value chain solution across production, storage, transportation and utilisation of hydrogen. Following this recent announcement, it appears likely that Hyundai will continue to seek domination in hydrogen innovation.
Applications (utilisation) of hydrogen
As indicated by Hyundai’s ambitious vision for clean hydrogen to power everything and be available everywhere, hydrogen can be used in a wide range of sectors, from fuel and power systems to the manufacturing industry. It was reported that in 2021 global demand for hydrogen was 94Mt, with 50Mt of the demand coming from chemical production (75 percent used to make ammonia and 25 percent for methanol production used in solvents, fuels and petrochemicals). About 40Mt of the demand for hydrogen goes to refining processes.
Much of our analysis shows that hydrogen storage innovation is directed towards tanks, which are most suited to using hydrogen on the move. Additionally, the Future of Hydrogen Analysis carried out by the IEA found that, by 2019, there were about 50 target, mandate and policy incentives in place that support hydrogen, with a major emphasis on transport. We have looked into the number of hydrogen storage patent application filings over the past 10 years for types of transport.
Figure 5: Ten-year overview (2013-2022) - global priority filings - hydrogen storage for particular modes of transport
Hydrogen storage specifically for use in rail transport appears to have the lowest innovation, with only a handful of applications specifically in hydrogen storage for rail systems. This low figure is likely due to the ease of electrification of current rail infrastructure. Innovations in hydrogen storage for motor vehicles is also low. Again, this seems likely driven by the dominance of electric vehicles as the favoured alternative to petrol or diesel engines and the long innovation and investment chain needed to replicate the existing electrical infrastructure for the hydrogen sector. However, there is a notable increase in hydrogen storage innovations for motor vehicles since 2020. Toyota and Hyundai are assignees on 80 percent of filings related to hydrogen storage for motor vehicles in 2021. Youon Technology Co accounts for the further 20 percent of filings in 2021, specialising in micro hydrogen generating machines, hydrogen powered bicycles and hydrogen fuel cells. The two major areas of interest for hydrogen storage innovation in transport are, by some distance, shipping and aviation. In 2018, the shipping industry accounted for 700 Mt of CO2 while the aviation industry accounted for 1.04 Gt of CO2 emissions. Clearly, there is significant scope to improve the sustainability of these industries. Hydrogen storage technologies for aviation have steadily increased over the past ten years, peaking in 2021. Hydrogen is widely accepted as a promising energy source to replace jet fuel in aviation because it has an energy-density-per-unit mass three times that of traditional jet fuel. Airbus is the top filer in this area, which reflects their ZEROe programme which aims to bring the world’s first hydrogen-powered commercial aircraft to market by 2035.
In our Aerospace section we observe that companies such as Airbus, Rolls-Royce and Tata Consulting Services are broadly researching hydrogen technologies for sustainable aviation applications. New patent applications in hydrogen storage technologies for ships have been rapidly rising since 2017. In 2018, Maersk, the largest shipping company in the world, announced its intentions to have carbon free-operations by 2050. Hydrogen is a clear forerunner in alternative fuels for shipping because of the relative ease in retrofitting existing ships with hydrogen storage tanks and fuel cells. However, challenges remain, particularly due to hydrogen’s storage properties. Hydrogen has a relatively low energy density as a gas, therefore liquefied hydrogen appears to be the more promising option for the shipping industry. In fact, in 2021, the world’s first hydrogen tanker set sail from Japan to Australia shipping test cargo. The ship, named Suiso Frontier, was built by Kawasaki Heavy Industries, and had a 1250m3 liquefied hydrogen storage tank onboard.
Conclusions
Despite a recent slowdown globally, the patent filing trends highlighted in this report – combined with the underlying move to a green transition and the beneficial properties of hydrogen – we anticipate continued innovation across all hydrogen technologies. It will take consistent and significant investment to foster innovation and hasten the widespread construction of the infrastructure to allow for adoption of cutting-edge hydrogen technologies. It appears apparent that some, perhaps more hidden, sectors will see the first major take-up of hydrogen technology. However, it’s unclear if the necessary support will be there to see adoption by more mass market, consumer domains. We are excited to see the innovation and real-world applications that await us in the near future.
