By Andrew Price, President & CEO
On October 17, the Independent System Operator New England (ISO-NE) published its preliminary annual peak load report for 2024, indicating that the peak electrical load in New England occurred on July 16 during the 5:00 PM to 6:00 PM hour. After unusually mild weather in 2023 – and the first September annual system peak since the regional forward capacity market was established close to two decades ago - the summer of 2024 was more typical for New England. A July heat wave caused air conditioning loads to spike and a peak electrical load was set in the afternoon of July 16, 2024. After adjustments, ISO-NE’s preliminary load report indicates that demand during the 5:00 PM to 6:00 PM hour on July 16th hit 24,366 MW.
As we mention frequently, peak load information is subject to change by ISO-NE as new data becomes available and adjustments are made. To highlight the impact of these adjustments, the peak load hour looked to be the 6:00 PM to 7:00 PM hour until the most recent update from ISO-NE. This is one reason that our self-help notices typically recommend a curtailment window spanning several hours. On July 16 our recommendation to participants of our ISO-NE Self-Help program was to curtail loads starting at 4:00 PM and continuing until 8:00 PM.
In addition to after-the-fact adjustments from ISO-NE, other factors make it difficult to predict the peak load hour with precision. These factors include: the influence of hundreds of individual companies responding (or not responding) to load curtailment notices throughout the region; the location and timing of summer thunderstorms; and the impact of the rapidly growing number of behind-the-meter solar PV facilities during late afternoon hours when solar PV generation falls off quickly.
The following chart shows hourly loads for July 16, published by ISO-NE on July 17, prior to any adjustments. The 6:00 PM to 7:00 PM hour (Hour 19) is the clear winner at 24,255 MW with the 5:00 PM to 6:00 PM hour (Hour 18 and the hour that ISO-NE recently indicated was the likely peak) over 300 MW lower at 23,921 MW.
As a reminder, the ISO-NE assigns every retail electricity account in New England a capacity tag based on its load during the hour of annual peak the prior year. The capacity tag is the contribution of each electric utility account to system demand during the single annual hour of peak load. This value (measured in MW) divided by the total load in New England during that hour represents that account's share of the roughly $1 to $2 billion in capacity payments ISO-NE makes each year to the region's electricity generators. If you can predict the hour when the annual system peak occurs, and are able to reduce your load that hour, you will have a smaller capacity tag and therefore be responsible for a smaller share of the total amount paid to generators. This is taken into consideration by electricity suppliers in quoting prices to serve your account, so a lower capacity tag will result in lower electricity costs the next year.
Capacity tags set during calendar 2024 will be used to determine capacity costs during the power year running June 2025 through May 2026. Regional utilities typically release customer capacity tags for each utility account in April/May.
Thank you to those that participated in our ISO-NE Self-Help program in 2024. The CES Self-Help program is always voluntary and without fees for our clients. There is never any obligation to respond to our notifications and, if you can respond during the hour of the ISO-NE system peak, 100% of any savings are yours to keep. If you wish to enroll (or unenroll) from our program – or have any feedback for us about the program – you can let us know by contacting your CES Energy Services Advisor or Nina Callanan @ ncallanan@competitive-energy.com.
Photo by: Sid Balachandran