The Impact of Hydroelectric Power and Other Forms of Generation on Grid Frequency Stability for the WECC Region

With the increased use of variable forms of generation such as wind and solar, there is increased concern not only about load matching, but grid stability itself. Hydropower plants often are proposed to back-up variable sources due to the ability of hydropower plants to store their fuel/energy. In addition to compensating for the hourly and daily variations in output from wind farms and solar plants, hydropower plants can also make significant contributions to grid stability through the capabilities of their governing systems. Other conventional forms of generation may not be making the same contribution to grid stability due to the fuel efficiency, pollution reduction, block loading and/or other operating restrictions implemented in their control systems. This paper will present the results of an analysis of recent government reports and an investigation into the control methods used by various forms of generation. This paper uses some of the concepts and models presented in (Undrill, 2010).