Using Cellular Automata Approach to Optimize the Hydropower Reservoir Operation of Folsom Dam

Erfan Goharian,Samuel Sandoval-Solis,Graham Fogg,Mohammad Azizipour

doi:10.3390/w13131851

Erfan Goharian, Samuel Sandoval-Solis + Show 2 more

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https://doi.org/10.3390/w13131851

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Abstract

While hydropower in California is one the main sources of renewable energy, population growth has continuously increased demand for energy. In addition, recent droughts reduced the amount of available water behind the hydropower dams to provide the water head needed to run the turbines in hydropower plants. A more sustainable alternative, instead of developing new infrastructure, is to enhance the daily operation of reservoirs to support hydropower generation. This study suggests a new optimal operation policy for Folsom Reservoir in California and hydropower plants, which maximizes hydropower generation and reduces flood risk. This study demonstrates the application of the cellular automata (CeA) approach to optimize the daily hydropower operation of Folsom Reservoir. The reservoir operation is a nonlinear problem, where the hydropower generation and elevation-area-storage functions are the main nonlinearity to accurately represent the daily operation of the system. Moreover, the performance of the CeA approach under two extreme climate conditions, wet and dry, was evaluated and compared to the operation during normal conditions. Results showed that the CeA approach provides more efficient solutions in comparison to the commonly used evolutionary optimization algorithms. For the size of the non-linear optimization problem designed in this study, CeA outperformed genetic algorithm for finding optimal solutions for different climate conditions. Results of CeA showed that although the annual average inflow to the reservoir during the dry period was about 30% less than the normal condition, CeA offered about a 20% reduction in average hydropower generation. The new operation policy offered by CeA can partly compensate for the loss of the snowpack in California’s Sierra Nevada under a warming climate. The approach and its outcomes support an informed decision-making process and provide practical reservoir operational guideline to remediate the adverse effects of hydroclimatic changes in the future.

Highlights

Hydropower is one of the renewable energy sources that supplies about 16% of total electricity generation and 85% of all renewable electricity globally [1]
The intra- and inter-annual variations of timing and volume of the reservoir inflow and the uncertainty associated with them complicate the operation of the reservoir, especially when the objectives are in conflict with each other
To maximize water supply during the dry season, peak inflows during the high flow season should be stored in the reservoir in order to be released later during the high energy demand season

Summary

Introduction

Hydropower is one of the renewable energy sources that supplies about 16% of total electricity generation and 85% of all renewable electricity globally [1]. Limited water availability associated with droughts constrain the generation of energy in reservoir hydropower plants, especially in arid and semi-arid regions. The optimal operation of hydropower plants is become increasingly important and has led to an increase in the total number of published works in this field during the past two decades e.g., [2,3,4,5,6,7]. In California, about 9% to 30% (average 15%) of electricity is generated by hydropower [8]. From this portion, about 50% of the state’s hydroelectric power is generated by flows from the Sierra Nevada Mountain Range in the eastern part of the Central Valley of California [9]

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Conclusion