Winter Storm Elliot Review

The first task taken on by TVECG is a review of the events of Christmas Week 2022 when winter storm Elliot resulted in the first TVA rolling blackouts in recent history. The TVECG report is now going out for review to our Participants and Sponsors. We prepared a detailed computer model of the event and compared the model results to actual TVA performance. We have also reviewed the TVA After Action Reports which can be found at TVA Reports. Some of the points made in the TVECG report are:

• Winter Storm Elliot was a strong, cold, and wide spread event and the most severe winter event in the region in several years, but not "once in a life time" or "once in a century" as it was characterized. In fact there have been a number of more extreme winter events over the past century. There is a significant chance of similar or even more extreme winter weather in upcoming years. It would be a mistake to dismiss Elliot as an extreme event, we must plan for such events.
• The TVA peak load of 33,425 mw was higher than the TVA load forecast predicted. Had the same weather event occurred mid week in January or February instead of during the holidays, the load could have been much higher. Also the load continued to increase as the temperature dropped and more portable electric heaters came into play. If the temperature had dropped further or was sustained longer the load could have been much higher. It is not unreasonable that a winter peak load of 40,000 mw could happen.
• Once the event was underway, all indications are that both TVA and the Distributor staffs did an excellent job of dealing with the situation. The rolling blackouts were a necessity, not a choice.
• The TVA Nuclear and Hydro plants performed at maximum capacity through the event.
• Three large coal units and a number of natural gas units failed due to weather related issues. TVA has developed a plan to address these issues and we can expect fewer cold weather related failures in future events.
• TVA did not report losing any generation due to loss of natural gas fuel supply. But other utilities did lose generation due to limitations on natural gas supply and if the TVA gas units that failed for other reasons had been available it is likely that TVA would have lost units due to fuel supply. With TVA having 3800 mw of new natural gas units under construction and with other utilities also expanding natural gas capacity we have to question the availability of natural gas for the next extreme event. This has raised questions regarding TVA plans for replacement with natural gas and TVECG will address this in upcoming studies.