Economic Analysis of CSP-Driven Hydrogen Production Using SOEC Plant Model: EBSILON professional

Abstract

This research paper aims to analyse the potential of a high-temperature solid oxide electrolysis process fed by thermal energy from a solar thermal power station. The paper is composed of three parts. It starts with analysing suitable CSP (concentrated solar power) systems for the optimum working conditions of a solid oxide electrolysis cell, SOEC (operates with steam in the range of 700-1000 °C). A brief introduction about SOEC, CSP systems, flow diagram and its engineering components are provided. An initial study of the existing high-temperature electrolysis methods is presented to identify the most efficient method and to study the boundary conditions of SOEC operation. In the second step flow diagrams and energy balances for the whole process are developed and the boundary conditions for detailed analysis are fixed. This forms the basis for quantifying and simulating CSP systems' assistance in producing hydrogen using SOEC. The developed flow diagram is simulated with the EBSILON professional software and analysis of heat transfer is carried out. Also, the required values for instance the mass flow, power requirement for water dissociation and heat integration, so on are taken from the developed model and used in further analysis. Finally, a techno-economic analysis is carried out using the LCOH (Levelized cost of hydrogen) methodology comparing the new approach with additional thermal input with the state-of-the-art approach of purely electrical-driven SOEC operation. It is found that heat integration is in principle beneficial in terms of energy efficiency. On the other hand, the integration of high-temperature heat within a very narrow temperature range imposes significant challenges for the overall system design and the associated additional costs. Furthermore, the evaluation indicates that the technical modifications for CSP heat integration have to be below 63MEUR to be competitive with the reference configuration of a pure electrically driven SOEC process.