Solar Tower System Temperature Range Optimization for Reduced LCOE

Abstract

New heat transfer and storage media offer for solar tower systems a much broader temperature range. Higher temperatures allow the integration of steam power cycles with increased efficiency. The present study evaluates modular solar tower plants using solid particles as heat transfer medium (HTM), allowing temperatures up to 1000°C. In a parameter study the influence of upper and lower HTM temperature on levelized cost of electricity (LCOE) is evaluated. The results show a significant impact of the HTM temperature selection, mainly governed by the HTM temperature difference. A high temperature difference results in reduced LCOE. The most important factors for this reduction are the cost decrease of particle inventory, storage containment, and particle steam generator. This decrease is partially offset by an increase in heliostat field and tower cost. The results indicate that the use of solid particles for high efficiency steam power cycles offers unique advantages due to the wide temperature range of the particles.