Long-term optimal hydropower reservoir operation with minimum flows and maximum ramping rates

by Ignacio Guisández

Institution: Universidad Politécnica de Madrid (UPM)
Department: Department of Hydraulic, Energy and Environmental Engineering
Year: 2016
Keywords: Electric Power, Hydrology
Posted: 02/01/2018
Record ID: 2187237
Full text PDF: http://oa.upm.es/43237/1/Ignacio_Guisandez_Gonzalez_2.pdf


This thesis studies the long-term operation of price-taker peak hydropower plants associatedto reservoirs and subject to minimum flows and maximum ramping rates that sell energy inday-ahead electricity markets. The thesis is organised in five chapters and two appendixes.The first chapter is an introduction of the above-mentioned issue. It aims to provide bothan overview as well as a mathematical description of the addressed problem and define thescope and objectives of the thesis.The second chapter shows a review of the literature related to the main topics tackled inthe thesis, such as the principal approaches of reservoir decision support tools, the optimisationtechniques most used in hydro scheduling, the main procedures for the characterisationof the involved random inputs and the methods most employed to estimate the generationcharacteristic of a peak hydropower plant. Furthermore, the chapter also presents a brief descriptionof the hydro scheduling models that have considered minimum flows and maximumramping rates jointly.The third and the fourth chapters are devoted to the achievement of the thesis objectivesand are divided in several studies. Among the main contributions cointaned in these studiescan be found different long-term optimisation models for hydropeaking subject to minimumflows and maximum ramping rates, several sensitivity analyses of the long-term effects ofthese constraints on certain economical and operational aspects of a peak hydropower plant,a set of formulae for the approximate assessment of the long-term economic impact causedby these constraints on this type of plants, and the introduction of a new concept in hydroscheduling: flow value.The fith chapter sets out the conclusions of the thesis which can be summarised as follows.On the one hand, the presence of minimum flows in hydropeaking increases the spillagevolume and the water value, whereas decreases the generated energy, the number of start-upsand shut-downs of the hydro units, the plant capability for price tracking and the revenue.On the other hand, the presence of maximum ramping rates, in turn, increases the number ofplant operating hours, the spillage volume, and, in the driest weeks, the flow value, whereasdecreases the number of start-ups and shut-downs of the hydro units, the plant capability forprice tracking, the revenue, the water value, and, in the wettest weeks, the flow value.The appendix A contains the equations involved in the developed optimisation models andthe appendix B provides a summary of the main data of the case studies considered in thethird and fourth chapters. Finally, both the cited references and the applied nomenclaturecan be found at the end of the thesis.Advisors/Committee Members: Prez Daz, Juan Ignacio, Wilhelmi Ayza, Jos Romn.