Techno-economic assessment from a transient simulation of a concentrated solar thermal plant to deliver high-temperature industrial process heat

The need for new technologies to provide economically viable sources of high-temperature heat without any net CO2 emissions for industrial chemical processes has become a global priority. Concentrated solar thermal heat generation can play an important role in meeting this challenge. We report a detailed bottom-up techno-economic analysis of a concentrated solar thermal plant to deliver process heat at a temperature of 1100 °C at the scale anticipated for a commercial demonstrator. The system consists of a 50 MWth solar concentration subsystem with heliostats and a tower, a novel solar expanding-vortex particle receiver (SEVR) and a packed bed storage system, together with a combustion back-up to allow continuous operation. The system was optimized to determine the minimum levelized cost of heat (LCOH) from a detailed transient model of the complete system. Significantly, the system with the maximum efficiency for the receiver or storage alone does not deliver the best annual energetic performance, highlighting the need to understand the detailed interplay between the two systems to optimize overall performance. While this system is not yet optimized for the lowest cost of industrial heat, the sensitivity analysis provides important insight as to how to move toward this optimum. This system yields the lowest values of LCOH for the solar component of between 37 and 39 USD/GJ for a corresponding annual solar share (SSann) of 28% and 53% of the total heat demand of the industrial process, respectively. However, importantly, this solar share can be almost doubled for only a 5% increase in LCOH.