Impacts of Wind-powered Generation Resource integration on prices in the ERCOT Nodal Market

In recent years many electric power grids, including the Electric Reliability Council of Texas (ERCOT), have seen a growing percentage of total energy coming from variable generation resources. In ERCOT, Wind-powered Generation Resources (WGRs) have been the primary source of this growth. As the penetration has increased, the influence of WGRs on market prices has also become more prevalent. This paper uses the ERCOT Nodal Market to explore the impacts of WGRs on both energy and Ancillary Service (AS) prices. To perform this analysis, typical energy offers for WGRs are first examined. In addition, ERCOT´s methodology for determining reserve requirements is modified to remove the effects of WGRs in an attempt to quantify the impacts of WGR output uncertainty and variability.