Final Report Summary - RESELYSER (Hydrogen from RES: pressurised alkaline electrolyser with high efficiency and wide operating range) Executive Summary:Alkaline water electrolysis for hydrogen production is a well-established technique available commercially in a wide power range. Hydrogen production by electrolysis is increasingly studied as a way to smoothen the fluctuating power output of renewable energy sources in oversupply situations. It is a way to introduce renewable energy into the transport sector and a necessary element of the energy system transformation in several European countries (e.g. Germany or Switzerland). However, some technological issues regarding the coupling of alkaline water electrolysis and Renewable Energy Sources (RES) remain unadressed. The project aims atAlkaline water electrolysis for hydrogen production is a well-established technique available commercially in a wide power range. Hydrogen production by electrolysis is increasingly studied as a way to smoothen the fluctuating power output of renewable energy sources in oversupply situations. It is a way to introduce renewable energy into the transport sector and a necessary element of the energy system transformation in several European countries (e.g. Germany or Switzerland). However, some technological issues regarding the coupling of alkaline water electrolysis and Renewable Energy Sources (RES) remain unadressed. The project aims at improving present electrolysers for the specifics of direct coupling to fluctuating power operation. Also system costs have to be decreased to reach a low cost but high-efficiency energy conversion.To address these challenges the project RESelyser - Hydrogen from RES: pressurised alkaline electrolyser with high efficiency and wide operating range - developed and investigated a new alkaline water electrolyser with improved components and a novel concept. A new separator membrane with internal electrolyte circulation (“e-bypass-separator”) and an adapted design of the cell to improve mass transfer, especially to reduce gas impurities at high pressures and low power operation, was investigated and demonstrated. Intermittent and varying load operation with RES is addressed by good electrode stability and improved efficiency in the new cell concept. Also the system architecture is optimized for intermittent operation of the electrolyser. The project partners combine their know how and experience to achieve the project objectives: the project coordinator DLR improves the electrodes, performs single cell tests and works on system concepts, VITO prepares new separator membranes, DTU characterises the electrode pore structure and Hydrogenics builds and tests the stacks as well as the system concepts.The following quantifiable results were demonstrated:• Total efficiency η=76% on HHV basis at a current density of 0.75 A/cm2 in a 300 cm2 cell, 82% for smaller cell• Materials used suitable for 100°C, tests up to 90°C• Electrode potential 98% of initial efficiency over 1100 on/off switching cycles• Estimate 2,300 €/(Nm3/h) plant capacity stack costs S2500 running at 65 bar, 7k€/(Nm3/h) for a Hex. S1000 65barg reselyser system• The gas impurity (O2 in H2) at 30 bar was about the same as for 10 bar in a conventional stack. Similar improvement for H2 in O2. I.e. the electrolyser can be run at a much higher pressure.Project Context and Objectives:Alkaline water electrolysis for hydrogen production is a well-established technique available commercially in a wide power range. Hydrogen production by electrolysis is increasingly studied as a way to smoothen the fluctuating power output of renewable energy sources in oversupply situations. It is a way to introduce renewable energy into the transport sector and a necessary element of the energy system transformation in several European countries (e.g. Germany or Switzerland). However, some technological issues regarding the coupling of alkaline water electrolysis and Renewable Energy Sources (RES) remain unadressed. The project aims at improving present electrolysers for the specifics of direct coupling to fluctuating power operation. Also system costs have to be decreased to reach a low cost but high-efficiency energy conversion.To address these challenges the project RESelyser - Hydrogen from RES: pressurised alkaline electrolyser with high efficiency and wide operating range - develops and investigates a new alkaline water electrolyser with improved components and a novel concept. A new separator membrane with internal electrolyte circulation (“e-bypass separator”) and an adapted design of the cell to improve mass transfer, especially gas evacuation, is investigated and demonstrated. Intermittent and varying load operation with RES is addressed by improved electrode stability, improved efficiency and a cell concept for increasing the gas purity of hydrogen and oxygen especially at low power operation as well as for high pressure. Also the system architecture is optimized for intermittent operation of the electrolyser. The project partners combine their know how and experience to achieve the project objectives: the project coordinator DLR improves the electrodes, performs single cell tests and works on system concepts, VITO prepares new separator membranes, DTU characterises the electrode pore structure and Hydrogenics builds and tests the stacks as well as the system concepts.The quantifiable project targets are listed in table 1 compared to the respective values for commercial alkaline electrolyser systems in 2011. Target projects:Efficiency: Efficiency >80% on HHV basis at a current density of 0.75 A/cm^2operating temperature: up to 100°CLong-term stability: Retention of >90% of initial efficiency over at least 1000 on/off switching cyclesSystem costs: Predicted modular system cost 3,000 €/(Nm^3/h) plant capacity for the complete systemState of the art at the beginning of the project:Efficiency: Total efficiency approx. 69% on HHV basis in a commercial electrolyser system using partly precious metal electrode coatings and lower current densityoperating temperature: approximately 60°CLong-term stability: High stability in on-off-cyclingSystem costs: 5,000 €/(Nm^3/h) plant capacity for the complete systemFurther details on the Summary description of project context and objectives are given in attached pdf-file Project Final ReportProject Results:Details on the S&T results/foreground are given in the section “Project results” in attached pdf-file Project Final Report.Potential Impact:Alkaline water electrolysis for hydrogen production is a well-established technique available commercially in a wide power range. Hydrogen production by electrolysis is increasingly studied as a way to smoothen the fluctuating power output of renewable energy sources in oversupply situations. It is a way to introduce renewable energy into the transport sector and a necessary element of the energy system transformation in several European countries (e.g. Germany or Switzerland). However, some technological issues regarding the coupling of alkaline water electrolysis and Renewable Energy Sources (RES) remain unadressed. The RESelyser project aims at improving present electrolysers for the specifics of direct coupling to fluctuating power operation. Also system costs have to be decreased to reach a low cost but high-efficiency energy conversion.To address these challenges the project RESelyser - Hydrogen from RES: pressurised alkaline electrolyser with high efficiency and wide operating range - develops and investigates a new alkaline water electrolyser with improved components and a novel concept. A new separator membrane with internal electrolyte circulation (“e-bypass-separator”) and an adapted design of the cell to improve mass transfer, especially to reduce gas impurities at high pressures and low power operation, is investigated and demonstrated. Intermittent and varying load operation with RES is addressed by improved electrode stability, improved efficiency in the new cell concept. Also the system architecture is optimized for intermittent operation of the electrolyser.It was stated in the electrolysis-development study [“Development of water electrolysis in the European union”, final report, E4Tech Sarl with Element Energy Ltd. For the fuel cells and joint undertaking, 2014] that “given successful cost reduction and system performance improvements, electrolysers are expected to become more widespread in energy applications, with hundreds of installations leading eventually to hundreds of megawatts installed capacity around 2020-2025.” This means that the topics addressed in this study might lead to a considerable electrolyser market.With today’s automobile traffic contributing to a significant share to the emission of fossile CO2 and therefore to global warming, the use of hydrogen from renewable energy sources as fuel for cars will make a major contribution to European Commision’s “2030 framework for climate and energy policy” (2014). According to this framework a reduction target for domestic 2030 greenhouse gas reduction of at least 40% compared to 1990 is set together with the other main building blocks of the 2030 policy framework for climate and energy. The German policy set up the goals to reduce greenhouse gas emissions by 40% as compared to 1990 in the year 2020, by 55 % until 2030, by 70 % until 2040 and by 80-95 % until 2050. These targets can only be met with almost complete supply of renewable energy for the transportation sector.Dissemination activities and exploitation of the results:The project ideas and results were presented at 16 conferences or meetings of the hydrogen community by 6 posters, 9 oral presentations and 2 exhibitions. 3 more oral presentations and 1 poster at conferences after the end of the project are submitted or have already been given. A summary of all dissemination activities is given in the table. More publications in peer-reviewed journals presenting the project results are in preparation.Many of the project results and lessons learned can be exploited at the industrial project partner Hydrogenics. For the plasma sprayed electrodes as a next step a commercial partner will be seeked for a joint development and later supply of the electrodes. For the e-bypass separator licensing will be discussed with VITO and a commercial partner for production. Any project results can also be licenced to interested parties outside the consortium. Also applications for the materials developed outside the applications considered in this project will be seeked.Further details on these dissemination and exploitation activities are given in the section “Dissemination activities and exploitation of the results” in attached pdf-file Project Final ReportList of Websites:Adresses For further details see the website of the project: www.reselyser.eu Project Coordination:German Aerospace Center (DLR)Institute of Engineering ThermodynamicsPfaffenwaldring 38-30D-70569 Stuttgart GermanyContact: Regine ReissnerTel. +49 711 6862 394E-mail regine.reissner@dlr.deProject participants: VLAAMSE INSTELLING VOOR TECHNOLOGISCH ONDERZOEK N.V. (VITO)Boeretang 2002400 MOLBelgium Contact: Yolanda Alvarez-GallegoTel. +32 14335612 E-mail: yolanda.alvarezgallego@vito.be HYDROGENICS EUROPE NVNijverheidsstraat 48cB-2260 Oevel (Westerlo)BelgiumContact: Jan VaesTel. +32 14 462 142E-mail: jvaes@hydrogenics.comDANMARKS TEKNISKE UNIVERSITETDepartment of Energy Conversion and StorageFrederiksborgvej 399 4000 RoskildeDenmarkContact: Jacob R. BowenTel. +45 4677 4720E-mail jrbo@dtu.dk Related documents final1-reselyser_final_publishable_290615.pdf
