There are different methods of storing electrical energy, such as batteries or hydraulic pumping. Most of them do not allow to cover the necessary demand or do not allow the long-term storage of large amounts of energy. But there is one energy carrier that can be stored and distributed in compliance with these requirements: hydrogen.
- What processes are commonly used for the production of green hydrogen? (the storage processes, moreover, will no longer be specific to H2green…)
Renewable hydrogen is produced almost entirely from the electrolysis of water, a process first carried out in the early 19th century. Today, it is primarily produced by three different technologies:
1) Renewable Energy plus Alkaline Electrolysis, both with separator and more recently with anionic membrane.
2) Renewable energy plus PEM electrolysis (proton membrane).
3) Photoelectrocatalysis (PEC) is a disruptive technology that allows converting solar energy into chemical energy in a single step.
Today, more than 70 Mt H2 is consumed per year (practically all of it grey hydrogen) and storage technologies already exist. Hydrogen storage involves a lot of volume and the most widely used technique for its conservation is in the form of gas, stored at very low pressure and is the most economical way to date, together with the liquid state, which requires very low temperatures and superior insulation. However, this consumption and storage is very focused on applications for industrial uses and the challenge is now to find new storage and distribution technologies that are cheaper or more focused on new applications such as mobility.
Renewable hydrogen is positioned as one of the key elements in meeting the decarbonization pathway set through specific targets established in the RED II. In order to guarantee the contribution of renewable hydrogen in meeting these objectives, the EU Hydrogen Strategy establishes three time horizons (2024, 2030 and 2050) for which it determines a succession of milestones to achieve. - Could you give us your vision of the evolution of H2Green 2030/2050?
Most forecasts, such as those of IRENA, estimate that by 2040 global hydrogen consumption will be approximately double the current level, around 140 Mt H2 per year. Of this amount, a minimum of 70 Mt H2 from renewable sources will be consumed per year, and this figure will increase depending on the rate at which current generation capacity is replaced by 2050 in order to reach the target of zero emissions.
In addition, the European Union (EU) approved its Hydrogen Strategy in 2020, which aims to produce up to 10 million tons of renewable hydrogen by 2030. To this end, it plans to allocate more than 470 billion euros to hydrogen generation and to reach 80 gigawatts (GW) of green hydrogen production capacity in ten years.
Evolution of the global hydrogen demand Hydrogen Council (link), IRENA (link)
3- Potential production and consumption of renewable hydrogen in Spain and its socioeconomic impact.
Spain has the opportunity to be a very relevant player in the energy sector in the future thanks to the great potential for renewable hydrogen production, fundamentally due to the large capacity of renewable energies with very competitive costs yet to be added to the system, which will allow the generation of renewable hydrogen at the lowest cost in Europe.
Spain also has its own Hydrogen Roadmap for 2030, approved in October last year, which aims to promote renewable hydrogen in industry and transport in projects that would mobilize around 8,900 million euros:
- 4 GW of electrolyzers installed in Spain.
- Minimum renewable hydrogen contribution of 25% of the total hydrogen consumed in 2030 in all hydrogen consuming industries both as a raw material and as an energy source.
- 5,000-7,500 hydrogen-fueled light and heavy-duty vehicles and 150-200 fuel cell buses
- Network of at least 100-150 publicly accessible hydrogen plants
- Continuous operation of hydrogen-powered trains on at least two medium- and long-distance commercial lines on currently non-electrified tracks
- Introduction of handling machinery using renewable hydrogen fuel cells and refueling points at the top five ports and airports in terms of freight and passenger volume respectively
The development of renewable hydrogen in Spain brings with it a clear environmental benefit, but also a series of economic and social benefits that could accelerate this development. On the one hand, the necessary new renewable energy facilities and green hydrogen generation facilities will generate many jobs, and in many cases these will be local jobs. On the other hand, this energy source can provide Spain with opportunities for reindustrialization and the development of hydrogen economy value chains, positioning the country as a technological reference. The hydrogen economy must be driven and supported by the development of the associated industrial and energy value chain, such as manufacturers of renewable hydrogen generation technology (photoelectrocatalysis, electrolyzers, etc? ), fuel cell manufacturers, component manufacturers (electronics, control, automotive, mechanical), vehicle manufacturers, shipyards, pressure vessel suppliers, suppliers of complete systems such as hydrogenerators or renewable hydrogen production plants, large-scale storage solutions, hydrogen transportation equipment, renewable hydrogen-based mobility service providers, etc. … these opportunities will foster innovation and growth in the Spanish energy industry, generating wealth and creating highly skilled jobs at every stage of the value chain, leading to sustainable economic growth.
In addition to the environmental benefit and the great socio-economic impact for our economy, it would imply gaining autonomy and independence and reducing imports of energy products from abroad, which after the events experienced in recent months and those we are currently living, it is shown as another fundamental strategic aspect, being a good example that the economy and the environment can often go hand in hand.
4- What are the main differences between the technology developed by Sunrgyze – photoelectrocatalysis – and conventional electrolysis?
In conventional electrolysis we can distinguish two stages, on the one hand, the generation of renewable electricity and on the other, the process of generating renewable hydrogen by means of an electrolyzer (alkaline or PEM).
Photoelectrocatalysis is a novel technology that allows the production of green hydrogen, 100% renewable, from solar energy by means of a process without external electrical input, which is called a bias free process.
called a bias free process.
This means that in the photoelectrochemical cells developed (Figure 2) the sun’s energy is used directly to carry out the electrolysis process, with the photons themselves directly providing the energy needed to carry out the electrochemical reactions of decomposition of water into hydrogen and oxygen, i.e., solar energy is directly transformed into chemical energy to split the water molecule.
Illustration 2. Sunrgyze photoelectrocatalytic technology (PEC)
This technology simplifies the green hydrogen production process with respect to electrolysis, the most widely used option at present, presenting competitive advantages, mainly in terms of hydrogen production costs and efficiency.
The results show that this technology is able to simultaneously satisfy three main requirements; high efficiency, stability and low cost:
- Overall efficiencies above 14% in terms of solar energy that is transformed into hydrogen (Sun To Hydrogen – STH), with forecasts of reaching up to 20%, which means doubling the current efficiency achieved in the process of an electrolyzer integrated with a solar photovoltaic plant (8-10%).
- Stability of the photoelectrodes, with more than 4,000 h operated in pilot plant.
- Design based on low cost and abundant materials.
Our photoelectrocatalysis technology allows operation in three different modes:
- Mode 1: Renewable hydrogen generation from solar energy (main mode).
- Mode 2: Renewable electricity generation
- Mode 3: Hydrogen generation through grid connection (for cases where 24-hour hydrogen production is required or when electricity prices are very low).
Illustration 3. Sunrgyze Photoelectrocatalytic Technology Pilot Plant (TechLab Repsol – Móstoles)
5- What are the main advantages of photoelectrocatalysis over conventional electrolysis?
Firstly, photoelectrocatalysis integrates the two processes in the same device (electricity generation and hydrogen generation). This, in addition to reducing investment costs (eliminating the need for power electronics, among others), allows higher process efficiencies (practically doubling the STH efficiency), since it eliminates all losses associated with the transformation of direct current into alternating current, the transport of energy from its place of production to the electrolyzer, the conversion of alternating current into direct current and the losses associated with the electrolysis process. All this allows obtaining a renewable hydrogen generation cost more competitive than other technologies (LCoH).
Secondly, it is a very easily scalable technology as it is modular and uses low-cost and abundant materials (no risk of future shortages). In addition, the operating conditions are milder than those of other technologies, which allows a high durability and useful life of all its components.
Thirdly, in the case of photoelectrocatalysis, being a bias free process, the cost of the hydrogen produced does not depend on the cost of electricity. This is a major difference with conventional electrolysis, where the cost of the hydrogen produced does not depend on the cost of electricity.
conventional electrolysis, where the electricity cost can be up to 70% of the final cost of the hydrogen.
6- What is the expected time horizon for market entry of the technology? How has the development of the technology progressed, has the validation phase been completed?
The technology began to be developed in 2012 as a Repsol R&D&I project and in 2018 Enagas joined to continue its development. During this period it has collaborated with several reference research centers, such as the Catalonia Institute for Energy Research (IREC), the University Institute of Electrochemistry of the University of Alicante or the Hydrogen Foundation of Aragon (FHa).
In 2021, a pilot plant was started up at Repsol’s Tech Lab, which has been in operation for more than 4,000 hours and where the technology and its TRL6 development status have been validated. Also in 2021, Repsol and Enagás created the company Sunrgyze, a company initially owned 50% by each company but which is currently closing the process for the incorporation of new shareholders and whose objective is the development, industrialization and commercialization of proprietary photoelectrocatalytic technology for the competitive production of solar hydrogen as an important step towards the decarbonization of Spanish and global industry.
Sunrgyze’s technology is based on three families of patents and has obtained more than 40 patents in more than 30 countries and in the coming months we expect the granting of another 20 patents that have already been applied for.
We are currently designing a Demo Plant that will produce 200 Tn H2 renewable per year and will be built at the Repsol Refinery in Puertollano with which we will finalize the validation of the technology reaching a TRL8-TRL9 and whose start-up is scheduled for early 2025. This project has obtained 4.5 M€ of funding from the European Commission through the Innovation Fund Small Scale Program, which grants innovative projects to decarbonize the economy.
From then on, after a period of operation and final validation, we will begin to commercialize the technology worldwide.
