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What to Expect During Controlled Outages

During extreme circumstances, and at the direction of ERCOT, the Texas grid manager, CoServ may have to initiate controlled, temporary interruptions of electric service called controlled outages to reduce demand and ensure the state electric grid’s stability.

If CoServ is required to help lower the demand on the ERCOT grid, we will initiate controlled outages. These controlled outages should only last 30 to 60 minutes per rotation.

Should you experience an extended outage of one hour or more, please utilize SmartHub or text OUT to 855-938-3496 to report a possible outage unrelated to this situation.

Click here to access and bookmark our Outage Map.

We want to do our part to keep the electric grid stable. To learn ways you can help check out our energy-saving tips.

Mandated Load Shed

Under Senate Bill 3, all Texas utilities, including electric cooperatives, are required to provide information related to load shed and critical accounts.

Who is ERCOT?

The Electric Reliability Council of Texas (ERCOT) manages the flow of electricity to more than 26 million Texas consumers. Visit to learn more.

What are controlled outages?

Controlled outages are temporary, controlled service interruptions designed to reduce consumer demand for electricity on the ERCOT grid. This is commonly referred to as load shed.

When do controlled outages occur?

If electric generation cannot meet consumer demand, ERCOT begins emergency operations and activates its Energy Emergency Alert System. Typically, before requesting controlled outages, ERCOT takes other steps to reduce demand, including requests for energy conservation. However, as a last resort and to prevent uncontrolled blackouts, ERCOT will instruct utilities to implement controlled outages. The outages could occur without notice because there are emergency orders from the Electric Reliability Council of Texas (ERCOT). All electric utilities must comply until ERCOT determines that controlled outages are no longer needed.

What should I do when ERCOT issues a call for conservation or an Energy Emergency Alert?

Everyone must work together to conserve energy when ERCOT requests conservation. Reducing electricity usage early could prevent the grid from reaching more critical levels that could force ERCOT to call for controlled outages. Visit our Energy Savings section for conservation tips.

What is a Residential Critical Care Account?

If someone who lives in your home uses life-sustaining equipment, your account may qualify as a Residential Critical Care Account*. Visit Critical Care – Residential Accounts for more information.

How do you qualify as a Commercial Critical Care Account?

Accounts that are critical during an emergency or provide major support to the electric system during an emergency may be listed as a Commercial Critical Care Account*. Visit Critical Care – Commercial Accounts for more information.

* Critical Care distinctions do not guarantee an uninterrupted supply of electricity. 

ERCOT Energy Emergency Alerts

The Electric Reliability Council of Texas (ERCOT) is a nonprofit corporation authorized by the Texas Legislature to manage the reliable supply of electric power to 24 million Texans, including residents and businesses in CoServ's service territory.

Before every summer and winter, ERCOT forecasts potential electricity demand and capacity. ERCOT currently expects to have sufficient generation to meet peak customer demand. If this changes, however, and it appears that demand will exceed supply, ERCOT will initiate its Energy Emergency Alert (EEA) system. Alerts range from calls for conservation to a declaration of a statewide power emergency that could result in controlled outages—controlled, planned service interruptions designed to ensure grid stability.

ERCOT Grid Normal

ERCOT grid conditions are normal.

Ercot Conservation Alert

Conservation Alert

ERCOT may ask consumers to conserve power by adjusting their thermostats and limiting the use of appliances.

ERCOT Conservation Needed

Energy Emergency Level 2: Conservation is critical.

Operators drop large commercial/industrial load resources that have entered contracts agreeing to be interrupted during an emergency.

ERCOT Conservation Critical

Energy Emergency Level 1: Conservation is needed.

ERCOT operators have the authority to call on all available power supplies, including power from other grids, if available.

ERCOT Controlled Outages

Energy Emergency Level 3: Controlled Outages in Progress.

ERCOT requires controlled outages to reduce demand and ensure the state electric grid's stability. These controlled outages typically last 30 to 60 minutes per rotation.


Who orders load shed and why?

When there is not enough generation available to serve consumers’ demand for electricity, and all other solutions available to ERCOT have been exhausted, ERCOT will instruct utilities to reduce power on the system to balance supply and demand. This is referred to as load shed. (Source: ERCOT)

How do we get to the point where Controlled Outages are necessary?

Physical Responsive Capacity (PRC) is a measurement of operating reserves to meet increased demand for energy.  PRC is similar to bench depth on a sports team.  These are resources that would be available and helpful in different ways to meet the needs of the team to accomplish their goal.

Energy Emergency Alert Level 3 is triggered when the PRC drops below 1,000 MW and is not expected to recover within 30 minutes.  This condition indicates that demand exceeds supply.  When this occurs, the system frequency will decrease.  To prevent damage and the possible failure of generators as they try to keep up with the increased demand, demand is reduced through controlled outages.

Why does CoServ have to comply with these requests?

ERCOT instructs electric transmission and distribution utilities to reduce power on the system to balance supply and demand.  CoServ is obligated to follow instructions from ERCOT under PUCT regulations.

These controlled outages help establish grid stability by keeping generators available.  Controlled outages are stopped when demand is anticipated to not exceed supply any longer and restoration will not jeopardize grid stability.  In a worst-case scenario, if the state’s electric grid become unstable and collapse, restoration could range from weeks to months depending upon the primary cause of failure.

How does CoServ conduct controlled outages and do some feeder lines or circuits receive priority?

Controlled outages are temporary, controlled interruptions of service.  They typically last 30 to 60 minutes. During these outages, service is interrupted to several feeders at a time to meet load shed requirements before rotating on to another section.

CoServ’s Critical Load designation is a listing of nonresidential Members that can be classified as public safety, industrial, or natural gas infrastructure, and have an approved Critical Load application with CoServ.  Critical load designations are determined based upon PUCT substantive rules.  When controlled outages are mandated, CoServ rotates feeders in the time blocks described while prioritizing designated Critical Loads for restoration as much as practicable.  Critical Load designation does not guarantee an uninterrupted, regular, or continuous power supply.

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