Texas Electric Grid

“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)

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 resources would be available and helpful in different ways to meet the team's needs 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.

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 becomes unstable and collapses, restoration could range from weeks to months depending upon the primary cause of failure.

CoServ continually monitors grid conditions and maintains contact with ERCOT. CoServ has several processes in place to communicate with Members during EEA events. Communications may include website and social media updates, email, SmartHub and text alerts.

Controlled outages 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 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 on 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.

If electric generation cannot meet consumer demand, typically during periods of extreme heat or cold temperatures, ERCOT begins emergency operations and activates its Energy Emergency Alert (EEA) 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 of 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.

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

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.

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.