Optical and thermodynamic analysis and optimization of a novel solar concentrating system for distributed power generation.

Abstract

A novel central receiver power system utilizing linked-tracking heliostats is analyzed for distributed-scale concentrated solar power. Smaller linkage groupings are typically found to have a lower impact on performance, with a 1x2 linkage causing a maximum system efficiency reduction of 1.64% in December, and a 5x5 linkage causing a 29.5% reduction. The results of the optical analysis are used as inputs to a thermodynamic analysis of thermodynamic power cycles. The concentrated flux drives a Brayton cycle operating with air, CO2, He, or H2. A combined Brayton-Rankine cycle is also considered with organic bottoming. Average 7-hour daily efficiencies are calculated for each month. The maximum daily average solar-to-electric conversion efficiency is calculated to be 16.2% with a single CO2 Brayton cycle and a 1 (east-west) x 2 (north-south) linkage setup. A peak system conversion efficiency of 18.2% was calculated when using R-141b as the working fluid in a bottoming cycle.