In Case of a Regional Power Grid Emergency

FAQ

Why would SWEPCO disconnect power during a regional power grid emergency?

If the Southwest Power Pool (SPP) declares an emergency requiring utilities to reduce the electric load on the regional power grid, SWEPCO puts its emergency plan into action. As the regional power grid operator, SPP would require the action as a last resort to avoid widespread power loss and to prevent long-term damage to the regional electric system. The action may be due to extreme temperatures, unexpected electric system problems, tight supplies of electricity across the region, or other power grid emergencies. SWEPCO would implement a series of controlled outages that temporarily interrupt power to customers in parts of its service territory, rotating the outages so that customers are not without power any longer than necessary.

What is the Southwest Power Pool?

SWEPCO is part of a group called the Southwest Power Pool (SPP) that operates the electric power grid in a multi-state territory. SPP makes sure – at any time of the day – that the amount of available power generation matches the amount of electricity needed by customers, plus an additional margin in case it’s needed. In a regional power grid emergency, they work with member utilities like SWEPCO to restore the grid to normal operations.

SPP does not own or operate generation or transmission facilities. Similar to air traffic controllers who monitor air space, SPP monitors and directs the electric power network to ensure that electricity safely and reliably gets to end-use customers in the region. SPP is a regional transmission organization and not-for-profit corporation mandated by the Federal Energy Regulatory Commission (FERC) to ensure reliable supplies of power, adequate transmission infrastructure and competitive wholesale electricity prices on behalf of its members.

Has this type of power grid emergency happened before?

The controlled outage event during the major winter storm in February 2021 was the first time in the 80-year history of the Southwest Power Pool that this kind of emergency has happened. However, SPP and member utilities maintain plans and regular drills to prepare for such emergencies.

What are "controlled outages"?

Controlled outages are efforts to reduce power to parts of the service territory and then rotate the outages to other areas to limit the length of outages for customers. "Load shedding" is the emergency reduction of load – or electric demand – on the power grid to avoid widespread power loss and to prevent long-term damage to the regional electric system.

How does SWEPCO decide which customers have power interrupted?

When SWEPCO must reduce the load on its electric system in an emergency, we use "controlled outages. The Southwest Power Pool (SPP) tells SWEPCO and other electric utilities how much electric load we must reduce.

In our emergency plan, SWEPCO matches the number of circuits that add up to the amount of electricity we are required to reduce. For example, a circuit might have 500 to 1,500 customers, and SWEPCO might need to disconnect 25 circuits. Those circuits would be in different locations around SWEPCO’s three-state service territory. SWEPCO would temporarily disconnect power to these circuits, and when possible, rotate to another group of circuits to limit the impact in any one location to one to two hours. It may take longer to get the power back on because of electric system issues or weather conditions. We make every effort to avoid interruption of service to critical public health and public safety facilities.

When SWEPCO gets word from SPP that the controlled outages have reduced power to bring balance back to the overall energy delivery system, then the controlled outages can end. During a longer emergency period, SPP could order additional controlled outages until the system returns to lower levels of emergency and then to normal operations.

Why isn’t there advance notice of controlled outages?

Emergency conditions on the electric system can change quickly during emergencies. The Southwest Power Pool (SPP) must act fast to protect the electric system and avoid bigger and longer outages for all customers, and long-term damage to the regional electric system.

SWEPCO and other electric companies must act immediately to reduce the amount of electricity demand on their system. We usually are not able to provide advance notice to specific locations or customers because we don’t know in advance how much electric load we need to reduce.

Usually, the first thing the public will hear is an emergency request to reduce use of electricity. If energy conservation action does not reduce electricity use enough, the additional emergency action may be needed, including controlled outages.

SWEPCO makes every effort to notify customers about the requests to conserve electricity and the possibility of further emergency action.

Does a request to conserve energy come first?

Whenever possible, a request to conserve energy comes before other emergency action like controlled outages. SWEPCO asks customers to reduce electricity use as much as possible. Use energy needed for your personal safety and to protect against property damage. But adjust thermostats, avoid using unnecessary lighting and appliances, and keep doors, windows and blinds shut to retain heat inside. Get tips here. Customers’ combined efforts can reduce overall demand for electricity and help ease the emergency situation.

How do customers help with energy conservation?

Individual customers’ efforts across the region make a difference. SPP operates the multiple-state electric system – balancing energy production and electricity use for the entire area. That’s why energy conservation in one place, for example North Dakota, can have a meaningful impact on electric reliability in another, like Arkansas, Louisiana, or Texas. And our efforts contribute to reliability at home and across the multi-state SPP region which serves customers in approximately 17 states.

What are the SPP’s emergency alert levels?

SPP uses the following Emergency Energy Alert (EEA) levels on the regional electric grid, summarized generally:

• EEA1 – potential regional power grid problems
• EEA2 – developing regional power grid problems – requires public appeal for energy conservation
• EEA3 – regional energy deficiency – requires load reduction through controlled outages by utilities
• EEA0 – end of regional emergency

For current grid conditions and more information about SPP alert levels, visit: https://spp.org/markets-operations/current-grid-conditions/

Where do SWEPCO customers get their power?

A customer’s power comes from the local SWEPCO power plant, but also from other SWEPCO plants in Louisiana, Texas, and Arkansas, along with wind facilities in other states, and some power purchases from other power plants outside the SWEPCO system.

Why is SWEPCO connected to other electric companies?

Electric companies are connected to each other so they can work together for reliable electric service. They help each other out when there are power plant or other electric system problems. They work to get their customers the best price on power from different power plants. They work together to plan and build the right transmission lines to deliver electricity where it needs to go.

What is SWEPCO’s history with the Southwest Power Pool (SPP)?

SWEPCO is a founding member of SPP. In 1941, SWEPCO and its AEP sister company, Public Service Company of Oklahoma (PSO), were among 11 companies that pooled electricity to power an aluminum plant at Jones Mill, Ark., for critical national defense. SPP was maintained after World War II to continue the benefits of regional cooperation.

Is SWEPCO in the same grid as most of Texas?

No. Most of Texas is in a power grid called the Electric Reliability Council of Texas (ERCOT). SWEPCO’s East Texas and Panhandle service territory is in the Southwest Power Pool (SPP), which is a neighboring but different power grid. We understand this can be confusing. For example, Mineola, Gladewater, Kilgore and Longview are in SPP (served by SWEPCO) while nearby Tyler is in ERCOT (served by another utility). Among American Electric Power (AEP) companies in the West, SWEPCO and Public Service Company of Oklahoma (PSO) are part of SPP. AEP Texas is part of ERCOT.