Spinning reserve service pricing in hydroelectric power plants

In the last few years, the electric sector has been going through the unbundling process of several participating agents and to the creation of a responsible market for all the occurring transactions. One of the services of great importance within this new electric sector is that pertaining to the services that contribute to the security, reliability and quality of the power supply. Such a group is referred to as ancillary services. Among the various types of ancillary services, spinning reserve is a service necessary for maintaining the integrity of the transmission system from either generation interruptions or load variations. This paper uses the application of the economic dispatch theory with the objective of financially quantify the availability of supplying spinning reserve in hydroelectric systems. The proposed methodology utilizes the generating units as well as their efficiencies so as to attend the total demand with the minimum water discharge. Thereafter, this value of demand is compared to that related with the dispatch which was realized following the guidance of the system operator. The difference in efficiency valorizes the availability for providing active spinning reserve. The proposed methodology was tested through the data provided by the Agua Vermelha hydroelectric power plant.