Energy and powerRenewables

Patent activity in electrolysis technology: Innovation driving cost reduction for green hydrogen

New joint report from the International Renewable Energy Agency (IRENA) and the European Patent Office (EPO) unveils the innovation trends in electrolysis technology to accelerate the cost reduction in renewable-based hydrogen production.

As more countries foster deep decarbonisation strategies, hydrogen produced from renewables via water electrolysis is expected to be at the very heart of energy transition as a key piece of the clean energy puzzle.

IRENA’s 1.5°C scenario projects that renewables-based hydrogen and its derivatives will account for up to 12% of final energy consumption by 2050. Several countries have already specifically included electrolyser capacity deployment targets in their national hydrogen strategies. Therefore, to respond to the growing demand for renewables-based hydrogen, an extraordinary expansion of the market for electrolysers is needed linked to a significant capacity increase in the manufacture and deployment of electrolysers.

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A reduction in electrolyser system costs is essential to enhance the competitiveness of renewable-hydrogen and technology innovation is crucial to this end. According to IRENA, investment costs for electrolyser plants can be reduced by 40% in the short term and 80% in the long term through key strategies such as improved electrolyser design and construction, economies of scale, replacing scarce materials with abundant metals, increasing efficiency and flexibility of operations, and learning rates with high technology deployment aligned with a 1.5˚C climate target.

The new patent insight report on innovation trends in electrolysers for hydrogen production, published today by the EPO and IRENA, uses patent statistics to reveal the trends and dynamism in the exciting field of hydrogen that can be produced using renewable electricity via electrolysis. With its charts and commentary, the report helps policymakers, technologists, companies, and investors to better understand these rapidly expanding technology domains.

The analysis shows that since 2005, patent filings for hydrogen production technologies have grown on average by 18% each year, a much higher rate than most technologies in the energy sector. In 2016, the number of international patent families for water electrolysis technologies surpassed the number of patents related to producing hydrogen from fossil sources (Figure 1).

Figure 1: This figure shows the 2005-2020 trend of patent families (left-hand side) and international patent families (right-hand side), comparing hydrogen production processes based on water electrolysis with processes using liquid or solid hydrocarbon feedstock. (IRENA)

The report also analyses five sub-technologies relevant for the electrolysis of water, which are important for reducing the cost of electrolysers (Figure 2):

• Cell operation conditions and structure: operating conditions at higher temperature and pressure are needed to increase efficiency of electrolysers without compromising durability and performance of membranes while also reducing costs.
• Electrocatalyst materials: scarce materials are a major barrier to electrolyser cost and scale-up, and solutions to replace such materials are needed, for example by using non-noble materials.
• Separators (diaphragms, membranes): reducing membrane thickness enables an increase in efficiency, which in turn enables a reduction in electricity consumption.
• Stackability of electrolysers (stacks): electrodes, bipolar plates and porous transport layers can contribute significantly to the stack cost. Improvements in these components, including their manufacturing, can lead to lower capital costs.
• Photoelectrolysis: photoelectrolysis can integrate electricity and hydrogen production in a single step potentially leading to cost benefits with the current challenges of low technology maturity and pathway efficiency.

Some important findings include that in 2018 inventions for electrocatalysts based on cheaper minerals surpassed the number of inventions based on more traditional but expensive electrocatalysts (which use e.g., gold, silver, platinum, or other noble metals), confirming the drive for cheaper alternatives. Photo electrolysis, i.e., splitting water into hydrogen and oxygen using light as the energy source, is a strong newly emerging technology with an above average number of international patent families, some 50% of which are filed by universities.

At the geographic level, Europe and Japan lead accounting for more than 50% of the total number of international patents filed in all the five sub technologies areas. While Europe leads in the stackability of electrolysers (stacks) (41% of the total patents in this area), electrocatalyst material (34%) and cell operation conditions and structure (32%), Japan ranks first in photoelectrolysis (39%) and separators (diaphragms, membranes) (36%).

The United States of America averages 18% across all technology areas while the Republic of Korea registers its highest share in separators (diaphragms, membranes) (16%) compared with an average of 7% across the other categories. Chinese international patents account for only about 4% across the five technology areas but China dominates in terms of the number of pure domestic patent filings.

Figure 2: This is a summary chart of the country share of international patents in relation to the five sub technology areas identified. The country refers to the country of the patent applicants. Europe groups together the 38 member states of the European Patent Organisation. Numbers in bold and in parenthesis at the top of each column are the total number of international patent applications in that technology area. (IRENA)

The great momentum observed in electrolysers is expected to continue and to spur future innovation. In fact, the rising trend in patent filings signals that more will come soon, addressing the urgent need for new solutions to lower the cost of electrolysers in parallel with raising technological efficiency and production capacity.

Photo electrolysis, i.e., splitting water into hydrogen and oxygen using light as the energy source, is a strong newly emerging technology with an above average number of international patent families, some 50% of which are filed by universities.

The demands for renewables-based hydrogen have never been greater and major innovations in electrolyser technology still need to happen to make this technology market-ready at industrial levels.

Innovations will be encouraged in the near future with the recent introduction in several geographical regions of major programmes dedicated to the development and deployment of a strategy on renewables-based hydrogen that would bring together different strands of action. From research and innovation to production and infrastructure to the international dimension.

Innovation in the field of electrolysers is a widely recognised strategy for making the production of hydrogen cost-competitive with other technologies and as green as possible, thus helping to tackle challenges such as decarbonisation and accelerating the energy transition.

Read the report.

About the authors

Francesco Pasimeni

Francesco Pasimeni is an engineer specialised in science, technology and innovation policy. He is currently Associate Programme Officer at IRENA leading the work on innovation, standards and patents for renewable energy.

Ufuk Sezer

Ufuk Sezer works for IRENA as a graduate intern on renewable energy innovation, markets and standards. He supports the innovation workstream in IRENA, focusing mainly on innovations for clean hydrogen and hydrogen derivatives.

Francisco Boshell

Francisco Boshell leads the work on innovation for renewable energy technologies at IRENA. He focuses primarily on providing policy advice and guidance to countries regarding technology innovation, quality control and standardisation programmes for a successful deployment of renewables.