Deep decarbonization of integrated power grid of eastern South Asia considering hydrogen and CCS technology

Abstract

This study integrates grid-connected hydrogen storage and carbon capture and storage (CCS) technology in a spatially disaggregated capacity expansion model, that can explicitly characterize the operational behavior of other conventional technologies. The model is then used to assess the decarbonizing pathways of the integrated power grid of four countries: Bangladesh, Bhutan, India, and Nepal of South Asia under multiple policy scenarios. The impact of the cost associated with hydrogen system components, and with capturing, transporting, and injecting CO2 in storage sites on the technology choices and their capacities are further evaluated through sensitivity analysis. The hydrogen storage system is effective in tapping surplus energy produced from intermittent renewables mostly in coal deficit regions for both short as well as long-term duration, but its large-scale deployment depends on electrolyzer and fuel cell cost reductions by more than 20% to compete against battery technology. In a very optimistic situation of 90% cost reduction, northern, western, southern parts of India and Bangladesh can completely decarbonize its power sector by 2050 through the installation of about 593 GW, 395 GW, 138 GW, and 120 GW of hydrogen storage tank. The storage and production profiles of hydrogen are influenced by seasonal, weather, and diurnal variations. Under limited solar PV and nuclear scenario, India should start operating CCS-based coal power plants from 2030 to meet the 80% emission reduction target and techno-economically feasible capacity requirements reach about 179 GW, 106 GW, and 35 GW by 2050 in the eastern, western, and southern parts of India respectively.