Influence of complementing power load uncertainty on the long-term benefits of hydropower operations

Abstract

Joint operation of hydropower and wind, solar power could explore the potential of reservoir regulation on complementing the power load uncertainty, which enhances the utilization efficiency of wind and solar power. To complement the power load uncertainty, hydropower would face a negative influence on its long-term benefit as the complementing operation strategy could deviate from its individual optimal policy. This study investigates the effect of power load uncertainty on the long-term benefits of hydropower operations using coupling model frameworks. It uses the martingale model of forecast evolution (MMFE) to represent the forecast uncertainty of power load and generate synthetic power load scenarios. Furthermore, a stochastic programming model for hydropower operation with explicit consideration of power load uncertainty is established for modeling the quantification of influence using the ending storage as long-term benefit evaluation index. Numerical experiments are conducted to examine the effect of power load uncertainty on hydropower operations. Results of study case of the Three Gorges project under different levels of power load uncertainty indicate that (1) the uncertainties of the reservoir storage, power release and power output increase with time for the accumulated influences of complementing uncertain power loads; (2) the uncertainty of end reservoir storage increases with the power load uncertainty; and (3) loss in long-term energy production would increase as power load uncertainty increases. The proposed methodology provides new insights for quantifying the negative influence of complementing power load uncertainty on the long-term benefits of hydropower station.