Economic Optimization of a Concentrating Solar Power Plant With Molten-Salt Thermocline Storage

Keywords

thermocline energy storage, concentrating solar thermal power, molten salt, power tower, economic analysis

Abstract

System-level simulation of a molten-salt thermocline tank is undertaken in response to year-long historical weather data and corresponding plant control. Such a simulation is enabled by combining a finite-volume model of the tank that includes a sufficiently faithful representation at low computation cost with a system-level power tower plant model. Annual plant performance of a 100 MWe molten-salt power tower plant is optimized as a function of the thermocline tank size and the plant solar multiple (SM). The effectiveness of the thermocline tank in storing and supplying hot molten salt to the power plant is found to exceed 99% over a year of operation, independent of tank size. The electrical output of the plant is characterized by its capacity factor (CF) over the year, which increases with solar multiple and thermocline tank size albeit with diminishing returns. The economic performance of the plant is characterized with a levelized cost of electricity (LCOE) metric. A previous study conducted by the authors applied a simplified cost metric for plant performance. The current study applies a more comprehensive financial approach and observes a minimum cost of 12.2 ¢/kWhe with a solar multiple of 3 and a thermocline tank storage capacity of 16 h. While the thermocline tank concept is viable and economically feasible, additional plant improvements beyond those pertaining to storage are necessary to achieve grid parity with fossil fuels.

Original Publication Citation

Flueckiger, S. M., Iverson, B. D., and Garimella, S. V., 2014, "Economic optimization of a concentrating solar power plant with molten-salt thermocline storage," Journal of Solar Energy Engineering, Vol. 136, pp. 011016. DOI: 10.1115/1.4025516

Document Type

Peer-Reviewed Article

Publication Date

2014-2

Permanent URL

http://hdl.lib.byu.edu/1877/6490

Publisher

ASME

Language

English

College

Ira A. Fulton College of Engineering and Technology

Department

Mechanical Engineering

University Standing at Time of Publication

Associate Professor

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