February 28, 2021
Tennessee

Lights off: Lessons learned from Texas power grid failure

Robert Houk | Johnson City Press | www.johnsoncitypress.com

Could a collapse of the power grid like the one that crippled Texas during a major winter storm earlier this month happen in Northeast Tennessee?

While anything is possible during a once-in-100-years severe weather event like the one that swept through the nation’s midsection nearly two weeks ago, BrightRidge CEO Jeff Dykes said this region’s power provider is “in a much better position to handle” such a scenario.

He said the Tennessee Valley Authority, which provides power to most of the area’s public utilities, relies on a more diverse mix of sources to generate the electricity that it sells.

And unlike the power grid in Texas, TVA is largely prepared to cope with the icy conditions and single-digit temperatures that left more than 4 million customers in the Lone Star State without electricity.

Where The Power Comes From

Dykes told BrightRidge board members last week that more than 51% of electricity in Texas comes from natural gas-fueled power plants. In comparison, 20% of power comes from gas generation in the TVA system.

Coal accounts for 13% of power production in Texas. TVA still generates 19% of its electricity from coal plants.

Nuclear, which represents 40% of TVA’s power generation, accounts for just 9% of energy production on Texas.

TVA produces 9% of its power from hydro generation, while there is no such option in Texas because the Rio Grande is not deep enough for hydro generation.

Solar accounts for 2% of power generation in Texas, and 4% in the TVA system.

Dykes said one big difference between Texas and TVA, which serves most of Tennessee, is the use of wind power. In Texas, nearly one-fourth of its total power supply comes from wind turbines.

Wind plays a very small part in TVA’s power grid, and most of it is purchased from other producers.

“The best place to put wind turbines in our area to maximize generation is the Great Smoky Mountains, and we know that is not going to happen,” Dykes said.

An Unfortunate Series Of Events

Dykes said a “domino effect” led to a collapse of the Texas power grid during the week of Feb. 15. He said the high temperature for an average day at that time of the year in San Antonio, Texas, is in the lower 50s.

A major winter storm brought subfreezing temperatures and snow across the region, resulting in residents “cranking up their heat.”

At the same time, ice was beginning to freeze the wind turbines that were built to withstand typical winter weather in Texas, not for more frigid regions like Minnesota, where heating units and other costly safety measures are installed in generating equipment.

“When the wind turbines started icing over, they became out of balance and started shutting down,” Dykes said.

With the wind turbines going off line, Texas power officials were forced to increase production from the grid’s gas-powered generators. At the same time, homeowners with gas furnaces were turning up their thermostats.

This put a strain on natural gas supply and reduced pressure for both power generation and direct heat. Voltage drops resulted in rolling blackouts and a substantial loss of service throughout the Texas power grid.

A Plan For Moving Forward

Dykes said the recent problems with the Texas grid will no doubt lead power providers nationwide to take a closer look at their plans for dealing with severe storms in the coming years.

“I think coming out of this there will be heavy planning for severe storms, and they will be bringing in the equipment to deal with the next 100-year storm,” Dykes said.

He said the TVA system has not been immune to weather-related damages to power supply. Major winter storms in 1993 and 1998 brought down power lines and left many electrical customers in Northeast Tennessee without power for weeks.

More recently, thunderstorms and tornadoes have damaged TVA transmission lines in Middle Tennessee and the Chattanooga area.


URL to article:  https://www.wind-watch.org/news/2021/02/28/lights-off-lessons-learned-from-texas-power-grid-failure/