With the summer months behind us, we’re growing increasingly more confident that the Annual System Peak is behind us as well. Although there have been a few early September days in some years that have provided a little drama, the Peak has never occurred in any month other than June, July, or August in the past 21 years, according to data from ISO-NE.
Behind-the-meter solar installations continue to cause variability and increase the difficulty for ISO-NE to forecast demand.
Late afternoon storms on some hot and humid days caused a significant drop in power consumption.
Demand forecasts on each of the days considered as potential Peaks were very close, within a few hundred MWs. There was never a day that was a clear outlier.
Utility programs that compensate end users for curtailing have increased the amount of curtailment that is implemented, further reducing demand when it is expected to peak higher.