Impact of Solar Thermal Power Plants on Economy and Reliability of Utility System

This paper presents an efficient methodology to evaluate the economical limitations as well as the marginal impact of the solar thermal power system (STPS) on the utility system reliability and operating cost. The economic limitation is formulated by evaluating the annual expected fuel cost saving due to the inclusion of the STPS and considering the installation cost of the STPS as well as the necessary transmission system. To find the marginal impact of the STPS on the utility system reliability and operating cost, a statistical method is developed to determine the equivalent load net of the statistically dependent STPS output and the load demand using their individual distributions. By this method, the statistical correlation between the STPS output and the load demand is carefully treated. Also, the sensitivity of the utility system operating cost and reliability to different penetrations of the STPS is developed.