4CP (Four Coincident Peaks)

4CP refers to the single highest 15-minute settlement interval of ERCOT system demand in each of June, July, August, and September. A facility's average demand across those four intervals sets its transmission cost allocation for the following calendar year. Because the stakes recur annually and the intervals are unknowable until the month closes, an industry of prediction, curtailment, and second-guessing exists around catching them. WattMarkets publishes its 4CP calls — and grades them in public.