Supplying the Japanese Transport Sector with Wind-Generated Hydrogen from Overseas

SUPPLYING THE JAPANESE TRANSPORT SECTOR WITH WIND-GENERATED HYDROGEN FROM OVERSEASPhilipp-Matthias Heuser1, Markus Reuß1, Thomas Grube1, Martin Robinius1, and Detlef Stolten1, 21 Institute of Electrochemical Process Engineering (IEK-3), Forschungszentrum Jülich GmbH, Germany2 Chair for Fuel Cells, RWTH Aachen Universtiy, c/o Institute of Electrochemical Process Engineering (IEK-3), Forschungszentrum Jülich GmbH, GermanySUMMARY: This study examines the technological and economic potential for Japan to import renewable energy from overseas in the form of hydrogen and strives to determine the cost curve for the respective hydrogen production regimes on the basis of wind energy, depending on the degree of wind potential utilization and the necessary import volumes. The overall costs of such hydrogen are composed of the levelized costs of wind electricity in the producing countries and the supply chain costs, depending on the transport distance. The respective trading link can be considered economical if the resulting hydrogen costs at Japanese fueling stations are price-competitive with regard to conventional fuels utilized in the mobility sector.Keywords: Renewable energy, wind power, wind-generated hydrogen, mobility, fuel cell-electric vehicles INTRODUCTIONIn light of declining fossil energy resources, climate change and growing electricity demand, hydrogen derived from renewable energy sources is a promising option for energy storage and transportability. Against the backdrop of the Fukushima Daiichi accident in 2011 and Japan’s goal to reduce CO2 emission by 26% by 2030 [1], the Japanese government is striving for an emission-free “hydrogen society” in which hydrogen will be the primary energy medium [2]. Due to a lack of capacity to economically generate hydrogen from renewable energy sources for domestic use, Japan is expected to become partly dependent on hydrogen imports [3]. On the other hand, several countries and regions around the world are estimated to have enormous wind potential that exceeds their own domestic energy demand, which can thus be utilized to produce emission-free hydrogen via electrolysis. Several scenarios incorporating this option have been discussed in past studies [3-5]. This study, however, focusses on the wind energy potential of the selected countries and regions, assessed by means of a highly spatially-resolved wind energy potential analysis, followed by a detailed investigation of the hydrogen supply chain elements between producers and Japan. Within the scope of this analysis, the supply of hydrogen for fuel cell electric vehicles (FCEVs) in passenger transport is analyzed on the basis of an assumed FCEV penetration in Japan of 50%.WIND ENERGY POTENTIAL ANALYSISIn order to determine the wind energy potential of candidate hydrogen sourcing countries, region-specific constraints for the placement of wind turbines are required. Using topographical databases, eligible land area for wind turbines can be determined. These databases contain detailed information on physical features such as bodies of water and rivers, protected areas and habitats, ter-rain elevation and slope, as well as settlement areas and infrastructure. Using a land eligibility model, developed by Ryberg et al. [6], the area of each province is mapped to a matrix of 300 m2 x 300 m2, where each matrix element is allocated a value of 0 or 1 according to eligibility factors derived from predefined thresholds and buffer zones from features found in the various topographical databases. A wind turbine placement model then determines possible locations of turbines within the eligible areas, accounting for a minimum distance between turbines. Following the basic concept of Robinius et al. [7], historic wind speed data from NASA’s Modern-Era Retrospective analysis for Research and Applications (MERRA) [8] and the DTU Global Wind Atlas [9] is used to calculate the full-load hours for every feasible wind turbine location. Using a standard power curve-based simulation approach, the full-load hours (FLH) for every located turbine are then derived. By imposing a minimum permissible FLH on the resulting distribution, several scenarios with different numbers of considered locations, along with the related electricity generation costs, are analyzed. With respect to these scenarios and the related degree of technological expansion, the respective wind turbine locations are concentrated within wind farms and internally connected. The related electricity production cost results from the respective FLH, the micro-grid connection costs and cost-optimal curtailment.HYDROGEN SUPPLY CHAINFrom the generated electricity, hydrogen is produced by decentralized PEM (Proton Exchange Membrane) electrolysis with an assumed efficiency of η=0.7. Converting the total wind-generated electricity requires a corresponding electrolysis capacity to be installed. Following conversion, hydrogen is compressed to 100 bar and transported by pipeline, which will be optimally designed to gather hydrogen in a tree structure and transmit it from the wind farms to a conveniently-situated harbor where it will be liquefied (LH2 = liquid hydrogen) or chemically-bonded into one of several possible liquid organic hydrogen carriers (LOHCs). Partial storage is then required to synchronize the fluctuating hydrogen generation from wind power and discontinuous shipments from the harbor. At this time, there are no ocean-going LH2 carriers of industrial scale, and so the LH2 carrier concept of Kawasaki Heavy Industries [3] is employed, wherein one hydrogen carrier features a capacity of 160,000 m³ (11,360 t) of liquid hydrogen. According to Kamiya [3], the carrier design is similar to LNG carriers and is in accordance with international regulations on ships that carry liquefied gas. It is mentioned that the amount lost to boil-off is limited to 0.2% per day and could be used as part of the fuel for the propulsion of the tanker; however, in this study a diesel engine is assumed for the carrier. Additionally, LOHC shipping is also considered, since LOHCs show similar transportation properties to crude oil. Thus, conventional liquid fuel tankers are employed to ship the LOHCs to Japan. Both carrier options would be offloaded at the harbor of Yokohama and provide the liquid or chemically-bound hydrogen to the domestic distribution system. Based on today’s fueling station locations (~26,000) and car stock per county (~7,500), hydrogen fueling stations in Japan would need to supply ~2 million tons of hydrogen per year. Depending on the shipping supply, the hydrogen is either transported to a fueling station via trucks, chemically-bound in an LOHC or as LH2, or centrally-dehydrogenated and transported by pipeline or GH2 (GH2 = gaseous hydrogen) trailer. The domestic distribution system is evaluated with regard to pipeline, as well as truck routing, based on the hydrogen supply chain model developed by Reuß et al. [10]. The setup of this analysis allows for the investigation of all pathways, which are shown in Figure 1, taking the costs of hydrogen at fueling station, the overall energy demand and greenhouse gas emissions into account. The expected results include the techno-economic wind potential of selected strong wind regions, the cost contribution of all supply chain elements and final hydrogen provision costs at the fueling stations in Japan. References[1] Tsukimori, O. Japan sets 26 percent cut in greenhouse gas emissions as target. (2015)[cited 2018/02/14]; Available from: http://www.reuters.com/article/us-japan-carbon-idUSKCN0PR0A220150717.[2] Behling, N., et al. Fuel cells and the hydrogen revolution: Analysis of a strategic plan in Japan. Economic Analysis and Policy. 48 (2015) 204-221.[3] Kamiya, S., et al. Study on Introduction of CO2 Free Energy to Japan with Liquid Hydrogen. Physics Procedia. 67 (2015) 11-19.[4] Ishimoto, Y., et al. Study of Demand for CO2-Free Hydrogen in Japan and the World. Proceedings of the Annual Conference of the Japan Institute of Energy. 22 (2013) 296-297.[5] Watanabe, T., et al. Cost Estimation of Transported Hydrogen, Produced by Overseas Wind Power Generations. In: 18th World Hydrogen Energy Conference WHEC 2010. Essen (2010) Forschungszentrum Jülich, Zentralbibliothek.[6] Ryberg, D., et al. Methodological Framework for Determining the Land Eligibility of Renewable Energy Sources. ArXiv e-prints. arXiv:1712.07840 (2017) [cited 2018/02/15]; Available from: https://arxiv.org/abs/1712.07840.[7] Robinius, M., et al. Linking the Power and Transport Sectors - Part 2: Modelling a Sector Coupling Scenario for Germany. Energies. 10 (2017) 957-979.[8] Gelaro, R., et al. The Modern-Era Retrospective Analysis for Research and Applications, Version 2 (MERRA-2). Journal of Climate. 30 (2017) (14) 5419-5454.[9] Badger, J., et al. A high resolution global wind atlas - improving estimation of world wind resources. in: Energy Systems and Technologies for the Coming Century. Danmarks Tekniske Universitet, Risø Nationallaboratoriet for Bæredygtig Energi, Roskilde, Denmark (2011) 215-225.[10] Reuß, M., et al. Seasonal storage and alternative carriers: A flexible hydrogen supply chain model. Applied Energy. 200 (2017) 290-302. Figure 1: Pathways to supply wind-generated hydrogen to Japa