The Emergency Load Curtailment Plan (ELCP) is a process the Tennessee Valley Authority (TVA) uses to address periods of high demand or other stresses on its transmission grid. The ELCP allows TVA and Local Power Companies (LPCs), to work together to mitigate the effects of extreme weather events or system damage.
These events typically occur during peak usage times when power consumption across the Tennessee Valley is highest. During summer, peak demand generally occurs between noon and 8 p.m., as air conditioners work to cool homes and businesses, and people are returning home from work to adjust thermostats, prepare dinner, and perform household tasks.
TVA is equipped to meet most power demand and normally would have enough generation capacity to handle typical fluctuations and some excess to spare. TVA can also purchase additional power from outside sources when necessary. However, in rare instances, these resources may not be sufficient. That’s where the ELCP comes in.
The ELCP is designed in a series of incremental steps, ranging from minor actions to more drastic measures, depending on the severity of the situation. Most frequently, TVA activates steps 10 through 30, which are designed to quickly address issues behind the scenes. The plan includes 60 steps in total, each with specific actions to manage power demand. Here’s a closer look at these steps and what happens when they are triggered.
Step 10: TVA and LPCs begin conserving power
When Step 10 is activated, TVA and Local Power Companies (LPCs) begin reducing their own energy use. Lights are turned off in offices and facilities, and heating or cooling systems are scaled back. In many cases, these initial internal conservation efforts are enough to reduce overall system load across the Valley.
Step 20: Voluntary conservation requested
At Step 20, TVA issues a public appeal asking end-use customers—including residential and commercial customers—to voluntarily reduce power consumption. Recommended actions include lowering thermostat settings, turning off non-essential lights, and shifting high-energy tasks such as laundry or cooking to non-peak hours. Commercial and industrial customers are also encouraged to postpone or limit non-essential operations.
Step 30: System-wide voltage reduction
Step 30 involves a 5% voltage reduction across the system. This measure, while still requesting voluntary conservation, reduces the overall power flowing through the grid—similar to lowering water pressure. While voltage is decreased, the system continues to meet essential needs and power remains available to all customers.
Step 40: Power curtailed to large users
Step 40 affects the largest power consumers in the Valley, including major industries and large commercial operations. TVA will implement this step only when absolutely necessary, due to the significant impact on affected operations.
Step 50: Rotating service interruptions (rolling blackouts)
Commonly known as rolling blackouts, Step 50 requires all LPCs to temporarily interrupt power to portions of their systems on a rotating basis. These outages typically last 30 minutes and move through different parts of the service area in rotation. Circuits serving critical infrastructure—such as hospitals or essential healthcare facilities—are exempt. As of Jan. 1, 2024, Step 50 had only been implemented once in TVA’s history, during the extreme cold weather around Christmas of 2023.
Step 60: TVA-initiated service interruptions
Step 60 is the most extreme level of the Emergency Load Curtailment Plan. At this stage, TVA would begin shutting off power to entire sections of the Valley to prevent a widespread grid collapse.
For comments from Greeneville Energy Authority President and CEO Dwayne Wells about the cutbacks, click on the link below:
TVA Urging Local Power Utilities And Residents To Conserve Energy During Hot Weather – WGRV.com
