Cost analysis of hydrogen production by high-temperature solid oxide electrolysis

We estimate construction and operation costs of gigawatt-scale solid oxide electrolysis (SOE) facilities for producing high purity hydrogen gas from water. Manufacturing and assembly costs for two types of SOE cell stacks are estimated using a detailed design for manufacture and assembly (DFMA (R)) analysis. Modular balance of plant (BOP) process equipment is designed and sized with Aspen (R), and cost estimated using equipment vendor quotes. Factory and on-site assembly and installation costs for SOEC stack and BOP equipment integration into modular SOE process units are calculated using a simplified DFMA (R) method. Total stack costs on a stack input power (SIP) basis reduce to <$100/kW(e) DCSIP for >500 MWe DCSIP/year production rates with electrode cermet, interconnects, and high-temperature heat treatments dominating the total cost. Integration of stacks with larger BOP equipment operating at higher pressures offers similar to 36% cost reduction in total facility capital cost due to an economies of physical scale effect since BOP equipment comprises >50% of facility costs. Optimized H-2 prices decrease from similar to$4/kgH(2) to similar to$2/kgH(2) for 1 GW(e) DCSIP facilities using $0.025/kWh electricity price. All costs are reported in 2021 US dollars.(c) 2023 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.