The Electric Reliability Council of Texas (ERCOT), the grid operator for most of the state, has implemented a wind-forecasting tool designed to help system operators prepare for large and sudden changes in wind production.
The new forecasting tool, developed by AWS Truewind LLC in collaboration with ERCOT system engineers, will help ERCOT plan for wind ramps – large and rapid changes in wind power production. Ramps can be caused by air-mass changes, thunderstorms, cold fronts, nocturnal stabilization, pressure changes and other transient atmospheric events.
The large-ramp alert tool makes calculations six hours ahead to warn the system operators of the risk of large and rapid increases or decreases in wind output. The ramp forecast calculates the values of magnitude and duration, and estimates the probability of a large ramp event beginning in a particular interval.
Information regarding the weather event that is most likely to cause the ramping event is also included, as well as additional characteristics for each predicted ramp event, such as most likely start time, duration and maximum ramp rate.
‘For example, we can look at the program and see a graph that may indicate a 45 percent chance of a system-wide wind generation decrease of 375 MW over 15 minutes, starting between 6:45 and 7 p.m.,’ says Kent Saathoff, vice president of system planning and operation at ERCOT.
The ERCOT region leads the nation in installed wind capacity – now at nearly 9,000 MW – almost a 500% increase in the last five years, Saathoff notes. On March 5, ERCOT recorded a new high for instantaneous wind output of 6,272 MW – serving 19% of the total load at the time.