Vice President of Procurement
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.
The spread in peak demand on three of the four days that we recommended curtailment was 115 MW, a 1/2 % variation. Initial ISO-NE reports indicated that July 20th resulted in the highest peak; however, subsequent reports indicate that August 4th was higher at 24,471 MW (preliminary and subject to change). Based on historical reporting, it is likely that August 4th will stand as the peak, but we’ll need to wait until ISO-NE officially reports it.
July 21st was an example of how storms impact demand. At 2 PM, demand was beginning to exceed the projection, but the storms that moved through around 3 PM reduced demand so that we could end the curtailment period earlier. (Note that if you are in a Utility program that implemented curtailment, you should follow the recommended time frame to ensure your program payments are not impacted).
The chart below not only depicts that the Peak is trending toward later in the day but also appears to be trending lower. The average Peak from 2001 through 2011 was 25,700 MW, vs. 24,833 MW from 2012 through 2022. The Peak only occurred once later than 3 PM in those first 11 years, compared to Peaking later than 3 PM nine times out of the last 11 years. Based on recent ISO data, the Peak hour of 6 PM on August 4th conflicts with the initial Morning Report data of 7 PM.
Future years will likely continue to present additional complexity in predicting the Annual System Peak based on weather, additional renewable generation, and implementation of energy efficiency measures. We will continue to do our best to keep you apprised of changes.