Energy Supply Through an Ammonia Supply Chain Using Ishikari Bay Offshore Wind Power and the Central Hokkaido Pipeline

The use of renewable energies is expected to expand towards carbon neutrality by 2050. However, as it takes a lot of cost and time to develop the electricity grid for the diffusion of renewable energy in Japan, this study examines the case for using existing natural gas pipelines for the transport of ammonia, which has a high hydrogen content. The economic performance of the proposed system is assessed using the discounted cash flow method, while the environmental performance is assessed from the air pollutant reductions of alternative coal-fired power generation. From the results described above, we will investigate the possibility of introducing ammonia supply-chain derived from renewable energy using the existing Natural gas pipeline. In this research, we examine Sapporo, Japan. Water electrolysis will be performed using the power of offshore wind power generated in Ishikari Bay, and the obtained hydrogen will generate ammonia, which will be transported by the existing Natural gas pipeline. The following three cases will be analyzed. The energy and exergy flow of these cases will be clarified to obtain the total energy and exergy efficiency of the system. Use the method of discounted cash flow to analyze the payback period years from energy efficiency. Analysis of the amount of electricity that can be supplied. The amount of electricity that can be supplied by the rated output of the proposed ammonia supply chain is 9.0 TWh per year, which can supply 94% of Sapporo's electricity.