The 2026 Heat Dome and PJM Energy Markets: Navigating Extreme Temperatures and Grid Reliability

For commercial and industrial facilities, understanding how these weather events impact the PJM Interconnection, MISO and neighboring grids is critical to maintaining operational continuity, managing energy costs and supporting broader system reliability.

With the right energy partner, businesses can move beyond simply securing a competitive rate. Dynegy helps customers evaluate usage patterns, understand peak-related cost drivers and identify practical strategies — including 5 Coincident Peak (5CP) and 1 Coincident Peak (1CP) management — that may help reduce costs and ease strain on the grid.

Understanding the 2026 Heat Dome Phenomenon

A heat dome occurs when a persistent high-pressure system traps hot air over a specific geographic region for an extended period. Instead of allowing heat to rise and dissipate, the high pressure acts like a lid, pushing warm air back down to the surface where it continues to heat up. This weather pattern can prevent cooler systems from moving into the area, resulting in prolonged periods of extreme temperatures.

The 2026 heat dome has settled over highly populated and heavily industrialized corridors across the East and Midwest. Because these conditions can persist for days or even weeks, they may reduce the overnight cooling periods that buildings, equipment and grid infrastructure often rely on to recover.

According to PJM forecasts, this extreme weather event could result in the region setting a new all-time summer peak for energy use. Current models predict a 07/02/2026 peak load of 166,304 MW. If reached, this demand would exceed the previous PJM record of 165,563 MW established in 2006.

PJM Emergency Orders and Market Actions

To manage the forecasted 166,304 MW peak, PJM initiated several progressive operational steps designed to maximize available power generation and prepare the market for potential supply shortages. These actions serve as early warning signals to market participants, utility companies and energy consumers.

Ahead of the forecasted extreme weather, PJM issued a maintenance outage recall on 06/25/2026. This recall requested that planned maintenance outages be returned to service to help maximize the amount of generation physically available to meet surging customer demand before the highest temperatures arrive.

As conditions intensified toward the end of June, PJM issued a comprehensive hot weather alert effective for the entire region through 07/03/2026. This alert is intended to prepare transmission and generation workers and facilities for expected increases in load and help ensure personnel are positioned to respond rapidly to localized equipment issues caused by severe heat.

For 07/01/2026, PJM elevated its response by issuing additional system alerts, including a load management alert to provide advance notice that an emergency demand response event could occur. This alert signals to commercial and industrial energy consumers enrolled in specific programs that they may be called upon to reduce grid reliance.

MISO Hot Weather Alert and 1CP Considerations

The Midcontinent Independent System Operator, or MISO, borders PJM to the west and also plays an important role in regional grid reliability. MISO issued its own hot weather alert on 06/29/2026 and made a conservative operations declaration for 07/01/2026 and 07/02/2026. Conservative operations typically involve suspending transmission maintenance, reviewing resource availability and operating the system with higher safety margins than normal.

For businesses in MISO, these periods are also important because of 1 Coincident Peak (1CP) exposure. Qualifying customers may have an opportunity to reduce demand during the hours when MISO is using the most electricity in each season. These seasonal coincident peak hours can impact monthly costs for a 12-month period, and forecasts can help customers identify when hourly peaks could occur so they can take action when operationally feasible.

Our 1CP communications may include:

• Morning alerts during parts of the season when peaks are more likely.
• High, Medium or Low probability indicators for potential coincident peak events.
• Weekly outlooks of load conditions and potential peak days.
• Additional alerts on medium- or high-likelihood days with a suggested time window for potential curtailment.

5CP: A Strategic Tool for PJM Customers

For businesses in PJM, 5 Coincident Peak (5CP) management can be an important part of an energy cost strategy.If a company can reduce demand during the five hours when PJM is using the most electricity of the year, it may be able to reduce capacity charges the following year.

Qualifying customers are subject to capacity charges based on their average contribution during the highest peak hour on the five highest peak days in summer, from June through September, across the PJM Interconnection. These 5CP periods help determine how much capacity the customer pays for over the next 12-month market year.

Dynegy’s 5CP service gives customers advance notice to reduce usage when demand peaks on the PJM system. Customer communications may include:

• Non-holiday weekday emails around 9:00 a.m. ET with the probability of a coincident peak event.
• High, Medium or Low probability levels to help customers plan.
• Weekly load-condition outlooks and potential peak days.
• Follow-up communications when a coincident peak is forecast, including estimated hours when the peak could occur.

For eligible Dynegy customers, 5CP is positioned as a practical way to save money, save electricity, and reduce strain on the grid.

Demand Response: Supporting Grid Reliability and Business Goals

Demand response is another structured energy market mechanism where commercial and industrial consumers may be financially compensated for reducing energy usage during periods of grid stress.

When PJM issues a load management alert, demand response participants may be placed on standby. The concept is straightforward: reducing load during critical periods can help restore the balance between supply and demand without requiring additional generation. For businesses, demand response can also create a potential revenue stream while supporting reliability across the broader system.

Demand response actions may include:

• Temporarily shifting or reducing energy-intensive operations.
• Shutting down non-essential equipment.
• Adjusting HVAC operations within acceptable comfort and safety limits.
• Using backup generation where appropriate and permitted.
• Automating load reductions through approved demand response programs.

Different programs may fit different business profiles. Some are designed for economic participation when prices reach certain thresholds, while others are tied to emergency grid conditions. Dynegy works with customers to evaluate which options may align with their operations, risk tolerance and business goals.

Voluntary Conservation Strategies for Businesses

Formal demand response programs require prior enrollment and specific load reduction commitments. However, every business can still play an important role by taking voluntary steps to conserve energy when grid conditions are tight. Even temporary reductions during peak afternoon and early evening hours can make a meaningful difference for regional grid stability.

When operationally feasible, businesses may consider the following actions:

1. Adjust thermostat setting: Raising cooling setpoints by a few degrees in large commercial spaces, offices or warehouses can significantly reduce HVAC demand.
2. Reduce non-essential lighting: Turning off decorative exterior lighting, shutting down lights in unoccupied areas and using natural daylight can provide immediate load reduction.
3. Shift energy-intensive processes: Moving heavy production, industrial baking, machining, large-scale charging or pumping operations to off-peak hours can reduce stress during the most vulnerable periods.
4. Temporarily reduce non-critical equipment loads: Facility teams can identify secondary systems that may be safely powered down without disrupting core operations.
5. Review energy usage during peak periods: High-demand events serve as a stress test for building efficiency. Monitoring which systems draw the most power can help identify future opportunities for efficiency upgrades, operational changes or demand management.

Partnering for Resilience and Strategic Energy Management

Navigating extreme weather events like the 2026 heat dome requires preparation, insight and the right market expertise. High-demand periods are an opportunity for businesses to better understand when and where electricity is being used, identify opportunities to manage demand and align energy strategies with broader operational and financial goals. Dynegy works closely with commercial and industrial customers to help evaluate energy usage patterns and demand management opportunities. Whether the goal is improving budget certainty through structured supply products, exploring demand response enrollment, participating in 5CP or 1CP forecasting, or identifying efficiency opportunities, informed decision-making is one of the best defenses against market volatility.