Hourly energy and reserve joint dispatch with a hydrothermal technological based representation

Abstract

Intermittent technologies are enhancing both the economic and technological value of ancillary services in the electric system. Some of these services, commonly denoted as reserves, have been liberalized and are offered in the balancing markets in the European Union countries, or in the regulation markets in the USA. This paper presents a deterministic single-node centralized energy and secondary reserve dispatch that outputs hourly scheduled energies and reserves, and both commodities prices. In this model, units of each generation company are simplified into technologies and sub-technologies for faster performance, but still considering inter temporal constraints such as ramps and responding time for reserves, and unit commitment decisions such as start-up and shut-down costs. Detailed shortterm hydro-thermal constraints (topology, efficiency, etc.) have been simplified by means of weekly constraints based on historical data (inflows, installed capacity, productions). The model has been validated by comparing its output prices and productions with the real ones occurred during 2010 in the Spanish market with very satisfactory results. Furthermore, a study-case on high penetration of solar generation reveals strong interactions between the energy and reserve markets and points out the importance of hydro technologies in the system.