Performance evaluation of Eskom´s linear Fresnel concentrating solar thermal pilot plant

This paper gives high level feedback on the main performance characteristics of Eskom´s first linear Fresnel, concentrating solar thermal (CST) pilot and demonstration (P&D) plant at Rosherville, Gauteng. This 150kW (Thermal) CST plant was financed by Eskom´s Research, Testing and Development (R, T&D) department and designed and constructed by a Gauteng-based, South African company (BBEnergy). The plant was completed with close to 100% local content early in 2013 and put into an automatic operating mode from July 1, 2013. A main objective of this study was to determine the actual radiation to thermal energy availability and the efficiency parameters of the plant. The data collected can be used in financial feasibility models, for direct electricity generation and/or feed water pre-heating scenarios (solar augmentation/solar boost). The plant has a total mirror area of 234m² and a maximum rated temperature of 250°C at 4000kPa (40bar). The main discussion points include a brief overview of the linear Fresnel collector (LFC) technology, a basic overview of the plant´s design features, the control system´s operating philosophy, the actual solar to thermal energy conversion ratio for a single day, the plant´s actual annual capacity factor and some important lessons learned regarding the significant availability influencing factors, during the plant´s first year of operation.