Techno-economical evaluation of renewable hydrogen production through concentrated solar energy

Abstract

This paper analyses renewable hydrogen production using concentrated solar energy considering a hypothetical production plant located in Guamaré, Brazil. The solar resource and the solar field performance for a typical meteorological year (TMY) were evaluated for this location.The thermochemical metal oxides cycle and the high-temperature electrolysis (HTE) were selected as hydrogen production paths due to their high development potential. For the HTE was proposed, a novel arrangement for a high-efficiency operation and the hydrogen production was carried out in a Solid Oxide Electrolysis Cell (SOEC) in thermo-neutral operation, driven by the electricity generated in a concentrated photovoltaic (CPV) system and heat obtained from the solar field, this arrangement uses tubular and closed volumetric receivers for the steam production and superheating, and a heat exchange network for heat recovery at SOEC outlet. In the thermochemical metal oxides case, a commercial CFD code was used to perform the reactor's thermal simulation, and the hydrogen production rate was calculated using different scenarios for the oxygen uptake capacity. In addition, an operation strategy was proposed to increase the hydrogen yield. Maximum year averaged sun to hydrogen efficiencies of 31.8% and 10.2% were obtained for the HTE system and the thermochemical metal oxide cycle, respectively.The hydrogen production cost was estimated for different production capacities and scenarios, leading to a hydrogen production cost of 4.55 US$/kg for HTE and 4.32 US$/kg for the metal oxide cycle for a long-term scenario and a production capacity of 2500 tonnes per year. Finally, a novel approach of hydrogen-production is proposed and evaluated, using HTE coupled with CPV and concentrated thermal energy. This approach has high development potential due to its high sun to hydrogen efficiency and the use of known technologies.