Small-Scale CSP Plants for Decentralized Power Production Using Piston Steam Engines

Abstract

While all concentrated solar power plants deployed since 2016 have had a nameplate capacity of over 50 MWe, there is a huge unaddressed market of 63 GW in Level 1 and 2 countries for smaller CSP applications between 100 kW and 2 MW. Using a previously developed piston steam engine model, we have designed a Small-Scale CSP (SSCSP) plant with a nameplate capacity of 1.2 MWe. The piston steam engine is divided into three stages, which allows two points for interstage steam extraction for feedwater preheating and a reheating loop. We designed an entire water-steam power block operating at 550°C and 60 bar with Ebsilon 15.2. The SSCSP concept relies on an Open Volumetric Receiver to provide hot air from solar radiation to a 12-hour storage unit and to the power block. Due to the small size of the system, we can use a north-field instead of a surrounding field, increasing the overall efficiency of the plant. With assumptions about the economies-of-scale and estimates about the current pricing of different components, we provide cost estimates for all hardware and indirect ancillary cost components. Operation and Maintenance cost can only be reduced with significant integration of deep automation, remote operations, machine learning, and robotics and drone technologies. Finally, we are able to provide an LCOE estimate which we calculate to 47 to 102 $/MWhe for a location with approximately 2400 full light hours per year.