The article “Optimizing Trading Decisions for Hydro Storage Systems using Approximate Dual Dynamic Programming“ [1], introduces a new approach for market-oriented optimization of cascaded pumped-hydro storage plants. The approach integrates optimization of hourly trading and dispatch decisions with medium-term planning of seasonal storages with seasonal planning. The article marks the starting point for the development of the QUASAR optimization software, and it already describes how to efficiently decompose stochastic programs with hundreds of time stages as well as how to discretize a multi-dimensional random data process to a scenario lattice. The computational backbone of QUASAR has evolved since the article has been published, for example, the runtime for the problem with seven cascaded hydropower stations could be decreased from 38 hours to 30 minutes.
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[1] Löhndorf N, Wozabal D, Minner S. 2013. Optimizing trading decisions for hydro storage systems using approximate dual dynamic programming. Operations Research 61(4), 810-823.