Combined cycle resource scheduling in ERCOT nodal market

Abstract

ERCOT has moved from a zonal market to an advanced nodal market since December 2010. In ERCOT, combined cycle trains (CCT) contribute a significant share of its total installed capacity. Therefore, how to accurately and efficiently model the CCT is one of the key factors for a successful EROCT nodal market. In order to facilitate market operations and ensure the system reliability, the ERCOT nodal market supports the modeling of CCT in two different ways: configuration-based modeling and physical unit modeling. The complexity of dependency within a combined cycle train is tackled by introducing state transition matrix. The scheduling and settlement for CCT in Day-Ahead Market (DAM), Reliability Unit Commitment (RUC), and Real-Time Market Security Constrained Economic Dispatch (SCED) are discussed respectively. Then, calculation of Locational Marginal Price (LMP) and Settlement Point Price (SPP) for CCT is completely discussed for both Day-Ahead and Real-Time Markets. Finally, a numerical example is presented to illustrate the implemented CCT modeling.