Proposed future Ancillary Services in Electric Reliability Council of Texas

The existing Ancillary Services (AS) in the Electric Reliability Council of Texas (ERCOT), Texas Independent System Operator (ISO), were developed in the late 1990s based on inherent characteristics of conventional synchronous generation in the grid. ERCOT system and its generation mix have undergone significant changes over the past two decades. Therefore ERCOT staff and stakeholders are currently developing a new Ancillary Services framework to allow a broader set of resources to provide services more efficiently while still maintaining adequate system reliability. This paper presents a future Ancillary Services framework that is currently being developed in ERCOT as well as the methodologies for determination of the AS requirements.