Operating reserves in the three most windy U.S. power markets: A technical review

This paper reviews the procured capacity of operating reserves and its relationship with increasing penetration of wind energy in the top three United States power markets that have most wind generation, including Electric Reliability Council of Texas (ERCOT), Midcontinent Independent System Operator (MISO), and Southwest Power Pool (SPP). Using hourly data for the period of January 1, 2014, to October 31, 2019, we find there was a stable or even declining trend of procured operating reserve quantities among these three markets, while wind energy production collectively grew by more than 80% during the study period. Our study finds that in all three markets the growing wind energy production has not yet significantly increase the magnitude and temporal pattern of net-load ramp, hence potentially rendering a stable or even declining need of operating reserves. The empirical results in this paper support arguments in extant literature that the impact of wind on the operating reserves is more likely related to deviations from normal operation conditions but not for a contingency event. The geographical distribution of wind resources in all three markets could have also helped to reduce the need of additional operating reserves.