Bob Corker, former Chattanooga mayor and Tennessee U.S. senator, is helping to lead an independent panel looking at how America's biggest public utility failed to deliver enough power to many of its 10 million customers during an arctic cold wave just before Christmas.
Corker is joining with the president of the American Public Power Association, Jay Ditto, and retired Electric Power Research Institute CEO Mike Howard to assess how the Tennessee Valley Authority prepared and acted during the winter storm that pushed up power demand more than forecast and left millions in the dark, at least temporarily.
The high winds and cold weather during Winter Storm Elliott idled TVA's biggest coal plant and some of its gas generation during the highest power demand period ever for December. As a result, TVA was forced to impose rolling blackouts for the first time in its 89-year history.
TVA President Jeff Lyash told local power customers last month that TVA takes full responsibility for the Dec. 23-24 power outages, and TVA Chief Operating officer Don Moul is heading an internal investigation into what went wrong during the cold snap.
Temperatures plummeted Dec. 23 at one of the fastest rates in history, and high winds and sub-freezing temperatures froze some sensory and equipment lines, idling both units at the Cumberland coal plant in Middle Tennessee and various gas-fired combustion turbines across the Valley -- both for TVA and for independent power producers that supply electricity to TVA.
Moul said the outside review by industry experts will help provide another perspective on TVA's activities and corrective action program.
"These leaders bring tremendous experience and expertise not only in public power and energy systems, but also an understanding of the growing energy needs of the region," Moul said in a statement Thursday. "As we work through our internal review and develop actions, we appreciate and value their independent review and insights."
(READ MORE: TVA developing plans for 20 small nuclear reactors to power Tennessee Valley by 2050)
TVA and Duke Power Co. both imposed rolling blackouts in December. The utilities' actions are also being reviewed by the Federal Energy Regulatory Commission and the North American Electric Reliability Corporation, which are investigating how power systems across the country operated during the winter storm.
"The effects of Winter Storm Elliott demonstrate yet again that our bulk-power system is critical to public safety and health," regulatory commission Chairman Rich Glick said in an announcement of the commission's study just after Christmas. "The joint inquiry with NERC will allow us to dig deeper into exactly what happened so we can further protect the reliability of the grid."
Reliability Corporation CEO and President Jim Robb said multiple energy emergencies were declared and new demand records were set across the continent during the cold weather this past month.
"This storm underscores the increasing frequency of significant extreme weather events (the fifth major winter event in the last 11 years) and underscores the need for the electric sector to change its planning scenarios and preparations for extreme events," Robb said in a statement.
TVA's inspector general office also said it is monitoring the utility's investigation to help decide what kind of reviews its office may conduct. The blue-ribbon panel is working to have some assessment and recommendations by the end of the month to help inform the new board of the Tennessee Valley Authority, which includes six new directors. The new board will meet next Feb. 16 in Muscle Shoals, Alabama, and is expected to review the power outages and recommended reforms, if any.
TVA said most of the local power companies it supplies were able to keep the rolling blackouts in December to "relatively short durations" for 15 minutes or so, in most instances. But the unprecedented call of short-term outages, in some cases, created power problems for local distributors and users that resulted in longer outages. Weather-related damages to some power lines and equipment also produced longer outages.
In Chattanooga, EPB was able to avoid rolling blackouts Dec. 23 when TVA reduced power by 5% to each of its 153 local power companies. EPB asked for voluntary power cutbacks and used its battery storage to help levelize its load.
But a longer and more severe 10% cut in power during the day Christmas Eve forced EPB to cut power, at least temporarily, to more than 100,000 of its roughly 160,000 customers.
"We exhausted every available measure before resorting to brief, controlled power interruptions in response to TVA's request for drastic load reductions the morning of Dec. 24, which were necessary to avoid more catastrophic, unpredictable and prolonged power outages," EPB spokesman J. Ed. Marston said in an email to the Chattanooga Times Free Press on Thursday. "Over the course of five hours, approximately 100,000 customers experienced a brief, controlled interruption lasting about 15 minutes. We intentionally excluded critical community service providers such as hospitals from this process."
Marston said there were about 3,000 EPB customers who experienced unanticipated outages lasting longer than an hour.
The Tennessee Valley Public Power Association, the Chattanooga-based trade group that represents the 153 municipalities and power cooperatives that distribute TVA power across its seven-state region, welcomed the additional review of last month's power outages.
"We are encouraged by TVA's post-event review process," association President Doug Peters said Thursday in a statement. "A thorough internal review of plans and processes, a deep dive into lessons learned and external reviews by both a diverse group of Tennessee Valley power company leaders and thoughtful business leaders from outside the industry will enable TVA to set benchmarks for success."
Contact Dave Flessner at dflessner@timesfreepress.com or 423-757-6340.