{{ content.title }}

Summer 2025 began with an unrelenting heat dome that blanketed the eastern half of the United States and parts of Canada, bringing with it intense and prolonged heat. Starting June 20 in the Plains and shifting into the Ohio Valley, Mid-Atlantic, and Northeast, temperatures surged well into the 90s and even 100s in many areas from June 23 through June 25.

Heat domes are unique weather phenomena that trap hot air beneath a layer of high pressure in the upper atmosphere (like a lid on a pot). The result: dangerously hot, humid conditions that linger for days. This particular heat wave pushed the electric grid to the brink as energy demand for air conditioning soared.

Energy demand and pricing skyrocketed

As temperatures rose, so did energy demand. Grid operators across North America faced one of their toughest challenges of the year so far and worked urgently to prevent blackouts and brownouts.

A growing concern this summer is tight reserve margins across several regions. Recent capacity auctions in PJM and MISO, for instance, revealed potential reliability risks due to insufficient resources available during peak events. The North American Electric Reliability Corporation’s (NERC) seasonal grid reliability assessment echoed these concerns. The report flags New England (ISO-NE), Texas (ERCOT), and the Midwest (MISO) as especially vulnerable to energy shortfalls during times of above-normal peak demand.

Several compounding factors are contributing to this unprecedented strain:

• Retirement or suspension of older generation assets that previously provided capacity, with no new assets ready to serve as replacements

• Surging load growth, driven by data centers, AI, manufacturing, and electrification

• Evolving accreditation rules that are changing how the grid values various resources in the energy mix

So, can the grid keep the lights on as we enter an unprecedented new era of climate-driven extremes and shifting energy landscapes? This heat wave may serve as a preview of what is to come. The system did hold, but not without stress. 

Here are a few key moments from those three days:

• PJM Interconnection, the grid operator serving 13 states in the Mid-Atlantic as well as Washington, DC, issued a Maximum Generation Alert on June 23, later extending it to June 25. The alert urged transmission and generation owners to defer any scheduled maintenance and keep assets online and producing power. During this period, PJM recorded its highest peak electricity demand since 2011, reaching 160,526 MW between 5:00 – 6:00 PM ET on June 23 – this number exceeds PJM’s summer forecast load of 154,000 MW. Elevated demand persisted into Tuesday and Wednesday.

• ISO New England (ISO-NE) declared a capacity deficiency on June 24 as extreme heat drove what is likely the region’s highest peak load since 2013. Similar to PJM, ISO-NE called on power plant operators to defer testing and maintenance to ensure assets remained online. 

• In New York, Governor Kathy Hochul issued a statement on Monday warning that the region’s grid operator, the New York Independent System Operator (NYISO), was approaching peak capacity and urged businesses and residents to conserve electricity. A second alert followed on Tuesday.

• Midcontinent ISO (MISO), the grid operator for 14 central states, saw system-wide demand hit 120 GW on Monday, its highest of the year so far. This news comes just weeks after NERC flagged MISO’s elevated reliability risk in its seasonal assessment.

Demand wasn’t the only thing that skyrocketed during this period – prices did, too. Some examples:

• New England: On Monday, spot wholesale electricity prices jumped more than $1,500 per MWh during peak times (around 5:30 PM ET). On Tuesday, prices soared three times higher than Monday’s.

• New York: Wholesale electricity prices in New York City soared to nearly $2,400 per MWh during peak evening demand. Wholesale prices in Long Island topped $7,000 per MWh.

Demand response stepped up

When the grid faces capacity constraints, as experienced during this recent heat wave, it has a multifaceted set of processes and resources that kick in to ensure reliability – some focus on generation, while others focus on conservation. One of the traditional methods of providing supply includes firing up peaking power plants that sit idle most of the year, reserved for high-demand periods. However, grid operators and utilities are increasingly recognizing the value of being able to dynamically control and balance the demand side of the energy equation, incentivizing consumers to reduce their electricity use when supply is tight.

One of the most effective tools in this strategy is demand response. Commercial and industrial companies that participate in demand response programs earn payments for making strategic energy reductions when the grid faces supply constraints, as we witnessed this week. Time and time again, demand response displays its value as a grid reliability tool, and this week was no different.

As a leading demand response provider for more than 80 demand response programs in the U.S. and Canada, Enel North America had an active week. Our team mobilized and responded at scale, coordinating with grid operators and utilities in advance of anticipated events. We proactively prepared and coached our customers with pre-event guidance and remained engaged throughout each demand response event to ensure optimal performance. We operated around the clock to deliver flexible capacity exactly when and where the grid needed it most. 

This is the level of service our customers have come to expect from Enel.

June 24 marked a milestone: our largest demand response event day in years, with nearly every major market in the eastern U.S. experiencing activity. And the numbers speak volumes. Over just three days, our team and participating customers:

• Offered more than 2.7 GW of flexible capacity in multiple regional markets 

• Responded to more than 120 demand response events across nearly 30 demand response programs

• Delivered more than 560 hours of demand response to help regional grid operators and utilities ensure reliability

• Delivered more than 10 GWh of load reductions

• Helped our grids avoid more than 1,800 tons of CO2 emissions

These contributions aren’t just numbers in a bulleted list. They represent real-time, measurable impact during the grid’s most challenging moment this year so far. They helped avert blackouts, protected public safety during extreme heat, and provided meaningful earnings to our customers who responded when the grid needed them.

Enel’s customers are grid heroes

Demand response works because of committed, responsive participants. Grid operators count on demand response capacity in their reliability planning, and during this heat wave, our customers delivered when it mattered most. We owe a huge thank you to our customers who activated their energy reduction plans, reduced their energy use during these critical moments, and worked with us every step of the way. Your dedication and responsiveness played a direct role in protecting grid reliability during some of the hottest, most demanding days we’ve seen in years.

Some regions experienced events on all three days of the heat wave, and we applaud the patience, resilience, and focus our customers demonstrated throughout this period. Your actions had real, immediate impact, helping keep the power on and air conditioning running not just for your operations, but for your entire community.

This is no longer a drill. This is likely the new normal. Gone are the days where audits are the primary demand response activity. Demand response was designed for exactly the type of scenario we experienced this week – emergency events. Federal Energy Regulatory Commission’s (FERC) Chairman Mark Christie acknowledged in a June 26 press conference that grid operators did in fact come “close to the edge” and that demand response was “essential.” This heat dome tested our electric grid, and some power outages did happen. But by showing up and stepping up during emergency situations, our customers proved once again that people, not just infrastructure, are key to avoiding a larger energy crisis.

You too can earn payments and reign in energy costs

Demand response is playing an increasingly vital role – not just for grid reliability, but as a smart strategy for companies looking to protect their bottom line. The events of the past week offer a glimpse into the future: a more dynamic, responsive grid – and how commercial and industrial participants are leading that transformation.

Participants in last week’s events didn’t just support the grid – they earned revenue for doing it. With advanced notice of potential grid disturbances, they were able to:

• Shut down or protect sensitive equipment at risk from voltage disruptions

• Shift load to backup generation where possible

• Avoid high electricity prices during peak periods

• Earn additional energy revenues in addition to protecting their availability payments

By working with a demand response provider, you can build a custom energy reduction plan that fits your operations, identify the right programs for your business, and confidently participate.

At Enel, we bring more than 20 years of experience across more than 15 energy markets in the U.S. and Canada. We support over 80 demand response programs and offer our DynamicDR software, which gives you real-time insights into market prices, demand forecasts, and optimal times to operate.

Since 2011, we’ve helped our customers earn over $1.9 billion in demand response revenue – and we can help you do the same. Many of your peers (and likely your competitors) are already taking advantage of this opportunity to protect their margins, their operations, and energy reliability in their community. Let’s connect and explore how you can benefit too.