Texas escaped a major disaster in February, almost losing its whole electrical grid due to severe winter weather. Millions of Texans were without power including some of my wife’s relatives south of Houston, where the inside of their house was a chilly 29 degrees for days causing water lines to burst. Some analysts say this could be the largest insurance claim event in Texas history.
Colorado will hopefully learn from what happened in Texas
There is a lot of finger pointing going on between both sides of political spectrum on who was responsible for the millions of Texans without power. Republicans are saying it was due to the high amount of wind power that Texas has installed in the past 10 years that has caused unreliability on the grid. Democrats are saying it was due to lack of winterization of natural gas backup that failed due to freeze ups of natural gas infrastructure. Both are somewhat true, but let’s look at some of the facts that has led Texas to this point.
Texas has become the largest generator of wind power in all of the US due to its high wind resource in west and southeast Texas. In the past 10 years, Texas has increased its wind generation from 9% to 23% of total generated capacity. One thing that is not being reported in most major news outlets is that Texas had also invested over 7 billion dollars in Competitive Renewable Energy Zone (CREZ) transmission lines during the past 10 years to upgrade its grid for all of this new wind generation.
The Electric Reliability Council of Texas (ERCOT) manages the flow of electricity for the majority of Texans. One of the missions of ERCOT is ensuring a reliable grid for its customers. The grid was far from reliable in mid-February during some of the most severe winter weather Texas has seen in decades. Five members of the ERCOT board recently resigned over this debacle, and all five resided out of state. The chair and vice chair of ERCOT (who both resigned) live in Michigan and Germany, respectively.
ERCOT is responsible for the way Texas has changed their electricity generation over the past 10 years where a significant amount of dispatchable reliable coal generation has been retired in lieu of more wind power generation (does this sound familiar, Colorado). Texas coal generated electricity has gone down from 39% in 2011 to 18% in 2020.
Wind generation is given priority on the grid due to its intermittency, and when the wind fails to blow or has mechanical problems then usually natural gas is used as a backup to fill capacity requirements. During the week Texas had its issues, wind generation went from supplying 42% of generation capacity at the beginning of the severe weather event to only 8% in the latter part of the week due to a drop in wind and frozen wind blades. To fill the gap, more natural gas generation had to be brought online, but the cold caused both an increase in demand for natural gas heating and freezes to occur in the natural gas infrastructure that precluded it from being a full backup.
During the week of severe weather in Texas it appears that it may have started with non-dispatchable wind power going down and then the failure of adequate grid backup. Since wind is given priority on the grid and due to its unreliability, it causes grid operators to constantly balance the system with the ramping up and down of more reliable backup/baseload sources (such as natural gas, coal, and nuclear). Taking more reliable sources such as coal generation off the grid in Texas the past 10 years may have caused more grid instability.
Colorado currently has about 20% wind penetration in their electric generation, but still has about 45% coal fired generation and 30% natural gas. Colorado plans to retire a good part of its coal generation over the next few years and replace it with less reliable non-dispatchable wind/large scale solar. This could put many Coloradans at risk of power outages. The Colorado Public Utilities Commission’s (PUC) policy of retiring reliable coal plants early could lead Coloradans to face the same fate as Texas in February, California last year, and in Australia in 2016 where a higher penetration of non-dispatchable unreliable wind/large scale solar led to grid instability. The PUC and our state’s utilities need to keep a close watch over the hearings that will be taking place over the next several months in the state of Texas to see what conclusions are drawn.
Even though the natural gas infrastructure should have been better winterized, it did provide a significant amount of backup generating capacity when the wind turbines went down, otherwise the whole Texas power grid would have failed and power outages would have lasted weeks if not months.
Steve Soychak has worked in various engineering and managerial capacities in the energy Industry for over 36 years. He is currently Program Director and on the faculty for the Energy Management/Landman program at Colorado Mesa University.
