ReliabilityFirst (RF) projects both the MISO and PJM areas to have adequate resources to serve normal electric demand in the upcoming summer season, including during expected periods in which certain generation resources become unavailable. This analysis is based on data provided by MISO and PJM, which we use to perform our annual summer reliability assessment.

While these 50/50 demand forecasts project MISO and PJM to have adequate resources to satisfy their respective planning reserve requirements, if resource outages and/or demand are experienced beyond the established projections, there is an increased likelihood that corrective actions (like Load Modifying Resources and Operating Reserves) would need to be utilized to serve forecasted load. The 50/50 demand forecast projects a 50% likelihood that demand exceeds projected load and 50% likelihood that it is below.

This risk of resource unavailability requiring corrective actions to be taken is elevated in the MISO area compared to the PJM area. When resource outages and/or demand are experienced beyond the established projections, PJM is at low risk while MISO is at an elevated risk for the summer of 2024.

MISO does anticipate increasing Maximum Gen events to call on their demand response programs, which provide an early alert that system conditions may require the use of MISO’s generation emergency procedures. These resources are only eligible to be used after all other online callable and dispatchable generation has maxed out.

The availability of MISO wind energy resources will also play a key role in determining whether MISO will need assistance from external (non-firm) resources during periods of more extreme demand levels. MISO has more than 31,000 MW of installed wind capacity, however historically these resources typically max out at approximately 5,616 MW of on-peak capacity.

Capacity and reserves

PJM’s planning reserve margin requirement is 17.7% for the 2024 planning year, and its forecasted reserve margins comes in above that figure at 27.6%. As a result, PJM is considered a low risk of electricity supply shortages this summer.

MISO’s planning reserve margin requirement is also 17.7% for the 2024 planning year and its forecasted reserve margin is also above that figure at 26.1%. However, the MISO area is considered to have an elevated risk of electricity supply shortages this summer if resource outages and/or demand are experienced beyond the established projections.

Since PJM and MISO are both projected to have adequate resources to satisfy their respective forecasted reserve margin requirements, the RF footprint as a whole is projected to have sufficient resources for the 2024 summer period.

Likelihood of generation unavailability

Exhibit 1 PJM Summer 2024 Outage Probability. The outage total across the horizontal axis of the graph is the number of outages that could occur during the five-year timeframe examined based on historical GADS data. The probabilities on the vertical axis are not based on a true statistical analysis of the available daily random outage data. Instead, these values represent the proportion of outages compared to the total resources available, then determines how often this proportion occurred within the five-year historical summer period.

RF’s summer assessment also evaluated the likelihood associated with different levels of generation unavailability for PJM and MISO. This analysis uses historical GADS data from a rolling five-year period, which provided a range of outages that occur during the summer period (i.e., May through September) of 2019 through 2023 (note: the distribution of random outages used for this assessment is not linear throughout the range of outages observed).

Exhibit 1 shows PJM’s summer outage likelihood based on different generation outage levels. For example, there is a 63% likelihood that PJM will experience 15,000 MW of generation unavailability this summer. The yellow load dots indicate that available resources are beginning to no longer be sufficient to serve the projected load including demand response and operating reserves.

Exhibit 2 MISO Summer 2024 Outage Probability. The outage total across the horizontal axis of the graph is the number of outages that could occur during the five-year timeframe examined based on historical GADS data. The probabilities on the vertical axis are not based on a true statistical analysis of the available daily random outage data. Instead, these values represent the proportion of outages compared to the total resources available, then determines how often this proportion occurred within the five-year historical summer period.

The 90/10 demand forecast is a more extreme model than the 50/50 demand forecast, projecting a 10% chance that demand exceeds extreme load. For 90/10 load, 26,200 MW of generation unavailability may require the operator to begin mitigating actions to prevent firm load shed (i.e., this includes using operating reserves, interchange transactions, and demand response).

For 50/50 load, 31,900 MW of generation unavailability may require operator mitigating actions. This analysis indicates that there’s a very low likelihood of this amount of generation outages occurring, making PJM a low risk for the upcoming summer.

Exhibit 2 shows MISO’s summer outage likelihood based on different generation outage levels. Since there is a lower amount of generator outages that need to occur before MISO operators need to take corrective action to stop firm load shed, MISO is at an elevated risk for the upcoming summer.