When ancillary services decrease with more wind in ERCOT

The extant literature predicts that increasing penetration of variable generation resources should have a profound effect on ancillary services for maintaining system frequency and reliability. However, a study of the ERCOT market found that between 2014 and 2017, the procured quantities of ancillary services continuously declined, while annual wind generation output increased by 26 million MWh. This article discusses potential reasons for the phenomenon of declining need for ancillary services and its implications.