NOAA forecasts above-normal temperatures for June through August across the U.S. with below-normal precipitation for much of MISO this summer.    

MISO forecasts to have enough electricity supply to meet expected consumer demand under typical conditions. However, there is the potential for elevated risk during extreme weather.

This summer, peak demand could reach nearly 123 GW, with about 138 GW of regularly available generation expected across the MISO footprint.

Severe Weather Preparations

Preparing for the possibility of extreme weather impacting the grid is a year-round task. That's why MISO conducts coordinated seasonal assessments, workshops, and drills year-round. Examples include: 

• Seasonal Readiness Workshops to prepare for the upcoming season
• Grid operator drills to identify potential challenges and develop solutions
• Fuel availability surveys and assessments with our members to identify potential risks
• After-action event reviews for major events that impact the MISO grid
• Constant and consistent communications with members and neighbors

 When severe weather is forecasted for the MISO region, operators can issue informational advisories and weather alerts to prepare for changing grid conditions. Our operators coordinate daily with neighbors and members to discuss generation and fuel availability. When necessary, MISO issues notifications to member operators which consist of situational awareness messaging and/or specific instructions designed to maximize MISO's ability to operate the bulk electric system reliably during abnormal and emergency conditions. 

The electrical grid is an interconnected network designed to generate and deliver electricity to consumers. It includes power plants, high-voltage transmission lines that carry electricity to substations, and distribution lines that bring power to homes, schools, and businesses.

MISO operates the high-voltage electric grid in much the same way air traffic controllers manage air traffic—ensuring safe and reliable flow 24/7. MISO doesn’t own the power plants, transmission towers, or lines—our members do. We simply ensure that the right amount of electricity is generated and transmitted safely and reliably to our member utilities, who then deliver the power to their customer.

To learn more about MISO and the electric industry, visit our Industry Foundations page.

The electric grid is a complex system that requires careful management to keep power flowing 24/7/365. MISO works closely with its members every day to ensure reliable power delivery and keep the lights on. During abnormal conditions, such as severe weather, MISO operators may need to implement emergency procedures to maintain grid stability and protect the electric system.

These emergency procedures allow operators to access resources not typically available, such as reserve and emergency generation, importing power from other areas, and collaborating with member utilities to reduce power usage.

If electricity supply can no longer meet demand, the final option to prevent widespread outages and protect the grid from long-term damage is to temporarily interrupt power to some consumers. This last-resort action, known as load shed, is rarely necessary.

When MISO anticipates tight electricity supply, we notify member operators about what we’re seeing, what to expect, and the necessary actions to take. These real-time notifications are posted on our website and can also be viewed on the MISO app.

The Grid Conditions gauge on the homepage shows current grid conditions based on available supply. The needle moves in response to active control room alerts, warnings, or event notifications related to supply issues:

• Green indicates normal grid conditions.
• Yellow signals alert and warning notifications.
• Orange and Red represent Energy Emergency Alerts (EEAs), with increasing severity.

By staying informed about grid conditions, consumers can better understand how MISO works to keep the power flowing and protect the grid’s reliability.

MISO’s emergency operating procedures establish requirements and instructions for members during supply and transmission shortages. Load shed is the last-resort action necessary to maintain grid reliability during system emergencies. MISO and its members play critical and distinct roles in executing load shed events. 

What is Load Shed, and Why Does it Matter? 

When the power goes out unexpectedly, one question comes to mind: Why? While many outages are caused by local issues—like downed power lines or equipment problems—some come from bigger challenges on the regional power grid.

One of the tools grid operators like MISO may use during a major emergency is called load shed. This means some electricity is temporarily turned off in specific areas to prevent much larger, longer-lasting outages. Load shed is an absolute last resort, only used when the stability of the bulk electric grid is at risk.

What is Load Shed and Why is it Necessary? 

Load shed helps prevent widespread blackouts and damage to the equipment that powers the electric grid. It’s used by all grid operators across the country and follows strict standards set by the North American Electric Reliability Corporation (NERC).

The electric grid must stay in balance. If supply and demand are not balanced, the system becomes unstable. That can cause automatic shutdowns of power plants and transmission lines—leading to major outages. Load shedding helps restore balance fast and protects the grid’s frequency, which must stay near 60 Hz.  

When Would MISO Shed Load? 

MISO may direct load shed during serious emergencies, including:

• Severe weather (like winter storms or hurricanes)
• Sudden power plant failures
• Transmission line damage or overloads
• High demand that outpaces available supply

MISO only uses load shed after all other steps have been tried. These may include bringing in extra generation, managing grid congestion, and purchasing emergency power.

What's the Diference Between a Capacity Emergency and a Transmission Emergency? 

There are two main reasons MISO might call for load shed—and they happen in different ways.

Capacity Emergency Load Shed

This happens when not enough electricity is being generated to meet demand. For example, extreme heat or cold might push demand way up, while power plants go offline due to fuel issues or equipment problems.

Capacity shortages usually happen gradually. MISO can often spot them early and take action—like tapping into reserves and/or bringing emergency generation online—before load shed becomes necessary.

Transmission Emergency Load Shed

This happens when electricity can’t reach the areas that need it, even if there’s enough power on the system. That might be due to a damaged transmission line, equipment failure, or heavy congestion on the grid.

These emergencies can happen suddenly and without warning. When they do, MISO has just minutes to act in order to avoid system overload or broader failures. Load must be reduced quickly in the affected area to keep the grid stable.

What Is MISO’s Role in Load Shed Events?

MISO coordinates the big picture. We don’t choose which homes or businesses are affected—that’s handled by local utilities. But we:

• Calculate how much load needs to be reduced
• Notify local operators with specific instructions
• Monitor the system in real time and stay in contact with neighboring regions
• Use tools like conservative operations and generation warnings to try and avoid load shedding in the first place

What Do Local Utilities Do?

MISO works with Local Balancing Authorities and Transmission Operators, who are responsible for carrying out the load shed instructions. They:

• Decide which areas will temporarily lose power
• Avoid shedding power from critical facilities like hospitals or emergency services
• May use rotating outages to limit the impact on any one group of customers
• Coordinate with MSIO to restore power as soon as it’s safe to do so

How Does MISO Prepare for Load Shed?

MISO takes emergency readiness seriously. We regularly:

• Hold drills and exercises with member utilities
• Practice for extreme weather, system failures, and other emergency situations
• Run monthly load shed drills to test systems and ensure fast response
• Identify areas for improvement and keep communication lines strong

In Summary

Load shed is always a last resort measure implemented to keep power flowing to the greatest number of people while protecting the bulk electric grid from potential damage. It can be  the safest and fastest way to prevent a much larger blackout. Whether caused by a capacity shortage or a transmission emergency, MISO works with its member utilities to act quickly, minimize impact, and restore power as soon as possible.

Our number one goal in a load shed event is always the same: Keep the grid stable and the lights on for as many people as possible.

What are rotating outages?

Rotating outages, also known as controlled load shed, are a strategy used by utilities to manage electricity supply during a grid emergency. The purpose of rotating outages is to keep the grid stable by reducing demand in a controlled, systematic way. Instead of leaving some customers without power for long periods, rotating outages temporarily cut power to different areas for shorter durations. This helps balance available supply with demand while minimizing inconvenience to customers.

In rare situations like this, MISO determines where and how much power to cut, while utilities implement the power interruptions and decide which customers will be affected.

What triggers outages?

Several factors can strain the grid and trigger the need for power outages. Extreme temperatures often increase demand for electricity while impacting the grid. Other factors include unexpected power plant or transmission line failures due to mechanical issues. Reduced generation from renewable sources, such as solar or wind, can also contribute to supply shortages, especially during cloudy or low-wind conditions.

How are areas selected for rotating outages?

When there is not enough electricity to meet demand, demand must be reduced. Power interruptions (load shed) are implemented to protect the grid from uncontrolled outages, and ensure power keeps flowing  to the greatest number of people possible. This emergency measure is always a last-resort option, directed by MISO.

MISO's role is to determine when, where, and how much power needs to be reduced. Once that’s determined, it is the responsibility of local utilities to carry out the load reductions, decide which customers will be impacted, and, if necessary, set the duration of the rolling outages.

What happens if MISO doesn't direct load shed?

Failure to direct load shed during emergency conditions could lead to  uncontrolled, cascading blackouts, disrupting power across large areas, including neighboring regions. These widespread outages can be far more damaging and may take days or even weeks to restore. By carefully managing load shed, MISO helps prevent such widespread disruptions and ensures a faster recovery.

How often do outages occur on the MISO grid?

Power interruptions on the MISO grid are extremely rare and typically occur only during extreme grid conditions.

How can I help prevent large-scale outages?

One of the best ways to help avoid large-scale outages is by reducing electricity use during times of high demand. Utilities may request that customers conserve power during emergency conditions. These requests are not common, but by following energy-saving recommendations, consumers can help protect grid reliability and reduce the likelihood of outages.

MISO, as a Regional Transmission Organization, has a specific role to play, and specific "tools" it may rely upon, when it comes to power restoration. 

Power Restoration Role and Responsibilities

MISO’s primary role during a power grid restoration in its region is to serve as a facilitator during the restoration process: coordinating, exchanging information, and maintaining stability.

MISO is responsible for the collection and exchange of information, as well as communication and coordination with the impacted entities.  Additionally, MISO is responsible for working with our impacted members to coordinate getting the power flowing again across the grid while maintaining stability so as to prevent a re-collapse of the system.

MISO also coordinates with its neighbors to ensure stability throughout the restoration process.

Restoration "Tools" or Procedures

MISO operators can rely on a number of emergency procedures to ensure grid stability and reliability during restoration. These "tools" can include sending emergency notifications and declarations to member operators in the MISO region. Some of the notification and declarations that could be issued include:

• Transmission Advisory
  • This communication tool is used for situational awareness. The message informs members that, based on projected system conditions, there may a transmission issue that will require specific actions to be taken in order to ensure reliability.
• Local Transmission Emergency
• This declaration identifies a specific entity or entities and provides instructions for mitigating a transmission emergency for a specific area of the grid
• Transmission System Emergency
• This declaration provides instructions for mitigating operating emergencies on the Transmission System that have the potential to exceed a pre-defined system operating limit that could lead to instability or outages.