Optimizing the Value-to-Cost Ratio for Central Receiver Electric Power Plants

Abstract

Typically, solar thermal power plants are designed to minimize the levelized energy cost. However, to maximize the benefit of a solar plant and, hence, maximize the wealth of an investor or a utility, a solar plant should be designed and operated with the objective of maximizing the value-to-cost ratio. This paper describes a value and cost analysis of solar central receiver power plants using molten salt external receiver technology. These plants were assumed to operate within the service area of the Southern California Edison Company. The SOLERGY computer code was used to simulate the performance of the solar plants using 1984 weather data for Barstow, California. A value-maximizing dispatch strategy that uses thermal storage to shift operation of the turbine from nonpeak demand periods to the utility’s peak demand period, is shown to greatly increase the value of a solar central receiver power plant with little increase in the levelized energy cost. Results are presented as functions of storage capacity, type of dispatch strategy, size of the field relative to the turbine, and turbine size.