Design and development of a next generation thermal rock bed storage experimental facility

The value of concentrating solar power (CSP) plants lies in dispatchability, which is provided through an integrated cost effective thermal energy storage system (TESS). A TESS consisting of a rock bed has the potential to reduce storage capital costs significantly, compared to current state of the art molten salt TESS. Further improvement of the Stellenbosch second generation rock bed design, for significant cost reduction, has previously been developed and built at Stellenbosch University (SU). This project focuses on improving the performance of the secondgeneration rock bed TESS, through partial re-design, predominantly aiming at maximizing the usable rock mass. The purpose of rock bed TESS is to find an alternative, low cost thermal energy storage system that is as effective and efficient as other conventional storage systems that are being used in the CSP industry. This paper presents an improved design contributing to cost reduction by the increase of usable rock mass, based on a previous SU design.