Synergy evaluation for joint expansion planning of green hydrogen and renewable electricity supply chains: A South Korea case

Green hydrogen is an attractive option for energy carrier, which can counteract the intermittent nature of renewable electricity production. While the synergy between renewable energy system and hydrogen system in this sense is obvious, its detailed analysis has only recently received attention. In this work, the advantages of joint planning (i.e., simultaneous planning of both energy and hydrogen systems) are analyzed in detail both qualitatively and quantitatively. In this work, a mixed-integer linear programming problem is proposed to this end to make optimal decisions for the combined system of green hydrogen and renewable energy, which we call an integrated supply chain of hydrogen and renewable energy (ISCHRE) system. The objective of such problem is to determine 1) the location and capacity of production, storage, and transportation & transmission facilities, and 2) the hourly operational decisions throughout the year to satisfy both green hydrogen and energy demands, while minimizing the total annualized cost of the entire system. Using the proposed model, the optimal ISCHRE system for South Korea is designed with the target of 10 % penetration of both nationwide hydrogen and electricity production. The national territory of South Korea is divided into five regions, and the decisions within each region and inter-region decisions are extensively analyzed. It was shown that, through joint planning, a significant cost saving can be achieved, showing a 20.8 % reduction in the total annualized cost. Also, despite the reduced renewable production, both hydrogen and energy demands were met through extensive bidirectional electricity transmission, which also decentralized green hydrogen production.