Operational benefit of transforming cascade hydropower stations into pumped hydro energy storage systems
Date
2022-07Source Title
Journal of Energy Storage
Print ISSN
2352-152X
Electronic ISSN
2352-1538
Publisher
Elsevier
Volume
51
Pages
104444-1 - 104444-11
Language
English
Type
ArticleItem Usage Stats
4
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Abstract
This study evaluates the potential benefit of retrofitting existing conventional cascade hydropower stations (CCHSs) with reversible turbines so as to operate them as pumped hydro energy storage (PHES) systems. We examine the energy generation and storage problem for a CCHS with two connected reservoirs that can be transformed into a PHES system in a market setting where the electricity price can be negative. We formulate this problem as a stochastic dynamic program (SDP) under uncertainty in the streamflow rate and electricity price. We analytically derive an upper bound on the profit improvement that can be obtained from the PHES transformation. We conduct numerical experiments with data-calibrated time series models and observe that the PHES system provides a greater benefit under more limited streamflow conditions or more frequently observed negative prices.
Keywords
Cascade hydropower stationsNegative electricity prices
Pumped hydro energy storage
Stochastic dynamic program
Streamflow rate