Solar Energy, Vol.188, 644-654, 2019
Benchmarking analysis of a novel thermocline hybrid thermal energy storage system using steelmaking slag pebbles as packed-bed filler material for central receiver applications
The aim of this research is to provide the techno-economic and benchmarking analysis of a 100 MWe class molten salt central receiver system using a thermocline hybrid thermal energy storage (TES) system versus conventional two-tank storage. The techno-economic analysis used has been carried out by means of specifically developed transient simulation models to find out a robust comparison between technologies. Thermal energy from storage, annual net electricity production and Levelized Cost of Electricity are the concise and comprehensive figures of merit of this study. An exhaustive effort has been made in order to achieve a well-founded comparison between concentrated solar power plants with equivalent storage system designs in terms of capacity factor and performance. Finally, this research demonstrates that the thermocline hybrid TES system provides a reliable cost effective storage solution that achieves the same Levelized Cost of Electricity as state-of-the-art technology. This is achieved due to the competitive price of the steelmaking slag pebbles versus molten salts, a revalorized processed steel by-product waste from the metallurgical industry used as packed-bed solid filler material for thermocline tanks. The results of this research open an attractive potential for cost reduction in the concentrated solar power sector, a key competitive value for a new market opportunity.