Demonstration of the SOLARSCO2OL sCO2 power cycle for future hybrid CSP-PV plants at the Évora Molten Salt Platform

Abstract

SOLARSCO2OL is an EU funded project that started in October 2020 with the following main objectives: to demonstrate a MW-scale recuperated supercritical CO2 (s CO2) power cycle operating from molten salts; to demonstrate a MW-scale molten salt electric heater to enable active hybridization of CSP and PV; and to investigate novel hybrid PV and CSP plants using sCO2 power blocks. The design of the key components and sub-systems of the cycle, namely the primary heater, the recuperator, the turbine, the compressor and the cooler and other balance of plant sub-systems, has advanced according to plan. The original demonstration plans, however, faced difficulties due to unforeseen market conditions, which in turn led to delays and to re-planning of the demo-site. Initially the demonstration campaign was targeted to be realized at the premises of La Africana power plant in Southern Spain, for which a completely new purposely-built facility for testing would have been erected. Instead, to overcome this challenge it is proposed to build upon existing facilities using molten salts. For this purpose, the Évora Molten Salt Platform (EMSP) has been identified as the most suitable industrial-scale facility in EU able to accommodate the plant, allowing to build upon existing molten salt systems and related expertise. The EMSP is a top stat-of-the-art recently inaugurated facility that hosts a first-of-its-kind molten salt parabolic trough collector system and a high temperature molten salt thermal energy storage (TES) system. It is owened by the University of Évora, and jointly managed and operated with the German Aerospace Center (DLR). Pre-existence of these systems would enable the SOLARSCO2OL consortium to save costs, while at the same time the demonstration of the technology at the premises of the EMSP would further enhance the visbility of the site and guarantee continuation in the operation of the facility while being extended to accommodate innovative components, thereby making the EMSP even more unique and positioning it as the first installation in EU and worldwide to host a MW-scale hybrid PV-CSP-sCO2 system. Through this integration, the SOLARSCO2OL consortium also welcomes University of Évora and DLR as project partners, whom bring on board additional skills and expertise in the field of CSP, complementary to the project. The successful operation of this demonstration will largely advance the maturity and readiness level of molten salts based sCO2 CSP plants enabling future large scale and commercial applications. This paper presents a preliminary description of demo plant and up-scaled molten salt hybrid PV-CSP-sCO2 systems.