Method and Case Study for Estimating the Ramping Capability of a Control Area or Balancing Authority and Implications for Moderate or High Wind Penetration: Preprint

In several regions of the United States there has been a significant increase in wind generation capability over the past several years. As the penetration rate of wind capacity increases, grid operators and planners are increasingly concerned about accommodating the increased variability that wind contributes to the system. In this paper we examine the distinction between regulation, loadfollowing, hourly energy, and energy imbalance to understand how restructured power systems accommodate and value inter-hour ramps. We use data from two restructured markets, California and PJM, and from Western Area Power Administration's (WAPA's) Rocky Mountain control area to determine expected load-following capability in each region. Our approach is to examine the load-following capabilitythat currently exists using data from existing generators in the region. We then examine the levels of wind penetration that can be accommodated with this capability using recently collected wind farm data. We discuss how load-following costs are captured in restructured markets, what resources are available to meet these requirements, why there are no explicit load-following tariffs, and thesocietal importance of being able to access generator ramping capability. Finally, the implications for wind plants and wind integration costs are examined.