North Georgia Electric Membership Corporation (NGEMC) is grateful for the patience of members during the holiday weekend. Tennessee Valley Authority (TVA) ordered all 153 power distributors in its seven-state service area to reduce electric load by 5% on Friday, Dec. 23, and 10% on Saturday, Dec. 24. The directive was the result of insufficient generation to cover the peak demand during single digit temperatures.
The emergency orders were issued after critical TVA generation assets failed early Friday morning. TVA lost 6,200 MW of generation as multiple units failed, including natural gas plants and at least two operating coal plants, and encountered complications securing off-system purchased power. This lost generation represents a significant amount of the power needed to meet the peak demand during the load reduction mandates.
The TVA power contract includes an Emergency Load Curtailment Plan (ELCP) to ensure power grid stability throughout TVA’s seven-state service area. All 153 TVA power distributors are required to adhere to the mandatory steps of the ELCP.
The timeline, which lacked sufficient warning or notice from TVA to the power distributors, is below:
- On Thursday, Dec. 22, TVA informed all distributors that generation systems were well prepared for the upcoming weather forecast and there was no anticipation of implementing the ELCP at any level.
- On Friday, Dec. 23, for the first time in NGEMC’s history, TVA ordered Step 50 in the ELCP at 10:31 a.m., requiring all distributors to immediately reduce load by five percent.
- As noted in the process detailed below, rolling blackouts were initiated to achieve the required load reduction. The order remained in effect until 12:43 p.m.
- On Saturday, Dec. 24, at 5:51 a.m., TVA issued Step 50 again requiring a 5 percent reduction in load. Within 20 minutes, TVA doubled the load reduction directive to 10 percent. The quickly changing orders and aggressive power interruption requirements from TVA meant NGEMC had to take immediate action and significantly change the rolling blackout pace, impacting many members on an hourly basis. The order remained in effect until 11:30 a.m.
- NGEMC reported all available real-time updates received from TVA as quickly as possible via NGEMC.com, local radio stations, media partners, emergency management agencies, and social media.
- During a conference call on Saturday afternoon with elected officials across its seven-state footprint, TVA CEO Jeff Lyash acknowledged that the agency’s communication with local power companies throughout the event was lacking. He went on to explain that TVA obviously fell short of the long-term commitment to never interrupt the power supply.
The overall ELCP Step 50 process is summarized below:
- When mandated to reduce load, NGEMC is required to intermittently interrupt power supply by implementing controlled rolling blackouts to achieve the ordered percent reduction.
- All distributors were required to immediately respond to the TVA load reduction directives to stabilize the power grid and avoid the potential for long term, uncontrolled interruptions.
- In performing the rolling blackouts under TVA orders, NGEMC’s operations team worked to avoid circuits serving critical safety infrastructure such as hospitals, 911 call centers, and traffic signals. This resulted in other circuits experiencing multiple interruptions.
- The blackouts were set to last 15 minutes. In some cases, the volume of rolling interruptions on the system shifted the duration to approximately 25 minutes as operators worked continuously to remotely open and close breakers to comply with the order.
While Christmas Day was normal from a power supply perspective, on Monday, Dec. 26, more NGEMC members were impacted when TVA’s transmission line serving NGEMC substations in Gordon County and the southern portion of Whitfield County went offline due to a broken transmission pole. Approximately 6,000 members were left without power. NGEMC’s operations team worked quickly to back feed all substations to restore power within approximately 45 minutes.
As your neighbors, we know these situations created challenges and frustrations, especially given the timing. We apologize for the interruptions and inconvenience. If you would like to share further comments with NGEMC, visit our "Contact Us" page to send a message anytime or call your local NGEMC office from 7:30 a.m. to 5:30 p.m., Monday through Friday.