Simulation of a Concentrating Solar Power Plant for the Chile Northern Region
Abstract
The deployment of renewable energy power plants is a priority of the Chilean government. A mandatory quota system requires that 5% of the electricity generated in the country must come from renewable energy sources, gradually increasing to 10% by 2024. As of 2010, only wind and biomass power plants have been installed in the country, while solar energy has received attention only for small-scale future demonstration projects. Concentrated solar power (CSP) plants are an interesting option for the country, especially when considering the high levels of solar radiation coupled with high values of the local clearness index and availability of flat terrain that are available in northern Chile. In this work, the modeling and simulation of a 20 MW CSP plant of the parabolic trough type, without thermal energy storage is carried out. In order to maintain the power block performance at nominal conditions during long non-insolation periods, most of these plants have a thermal storage system or contain a heat support (such as fuel). Because of that, a proper solar field size, with respect to the electric nominal power, is a fundamental choice. A too large field will be partially useless under high solar irradiance values whereas a small field will mainly make the power block to work at part-load conditions. A sensitivity analysis is conducted in order to determine the influence of solar field area and radiation levels, and the optimal plant configuration and solar field area are obtained as a result. The CSP plant is simulated using the TRNSYS computational tool and monthly and annual electricity yields are obtained from hourly simulations that consider radiation levels, solar field, and power plant characteristics. Therefore, it was found that Chile has an outstanding potential for CSP plants, especially in the northern locations of the country such as Antofagasta.