Ancillary Service Methodology

Ancillary Service Methodology

The Gist Every year ERCOT looks at historical data to determine how much Ancillary Services (reserves, or ‘AS’)  it needs to procure over the coming year.  Currently it does this for four reserves; Regulation Up (REGUP) , Regulation Down (REGDN) , Non-Spinning Reserves (NSRS, or NonSpin), and Responsive Reserves (RRS).  The current (as of 1/1/2022) …