By Andy May
I live in Texas and write about climate science and energy, so I get a lot of questions about recent issues. My wife and I are fine, we have a natural gas powered generator and we haven’t lost electricity like most people did earlier this week. We also had a broken pipe, but it was outside the house and I was finally able to plug it with the help of a neighbor after the normal (for me) three trips to the hardware store and two failed attempts.
As is common nowadays, discussions about natural events quickly turn into useless political arguments about who or what is to blame. Little thought is given about technical or scientific issues; everything is viewed through the prism of democratic or republican political agendas. Ideology trumps common sense. So we have Democrats blaming natural gas shortages and coal downtime and Republicans blaming the collapse of wind power. What really happened?
The chronology
Texas is a great place; It is 1,387 km wide and 23% larger in area than France. The weather varies widely from northwest Texas, where the wind turbines are located, to Austin, San Antonio, and Houston, where some of the worst problems occurred. So let’s look at the data. In Figure 1, we see electricity generation from February 7th to February 18th.
Figure 1. EIA chart of ERCOT data generated hourly from February 7th to 17th.
Monday evening, February 8th, West Texas was just freezing, with patchy freezing rain and sleet and 100% humidity. See figure 2.
Figure 2. Weather Underground historical weather for Midland, Texas.
Figure 2 shows some of the critical weather statistics for Midland, Texas, near wind turbine country West Texas. What is not shown is the humidity. The sudden drop in temperature started on Tuesday February 8th and the humidity quickly rose to 100%. No measurable precipitation occurred between February 8th and 13th, but condensation water froze on the wind turbine blades. The condensation was generally concentrated on the leading edge of the blades, which directs the wind around the blade and creates the spin and force. The ice on the blades, especially the ice on the leading edge, stopped the blades from turning.
As Elliot Hough, an engineer, put it:
“The turbine blades, and especially the leading edge that directs the airflow around the blade to create lift, become covered with ice and eventually lose all lift. In the case of a turbine blade, this means that the turbine no longer rotates. In the case of an airplane, the airplane falls to the ground. When the air is well below freezing, there is little to no moisture in the air and the blades will not freeze. These are the conditions much further north in North Dakota where temperatures can be subzero F and the turbines won’t freeze. “Elliot Hough on Linkedin
When these conditions occur on aircraft about to take off, the wings are de-iced with a chemical that melts the ice and stays on the wings long enough for the aircraft to reach an altitude where the humidity is low enough that no ice forms. But wind turbines are on the ground and if the humidity remains very high for three days, as in West Texas, and temperatures continue to drop, they fail.
When the wind turbines were frozen, natural gas combined cycle power plants switched on. These were all over the state. Natural gas production is usually a very good safeguard. It’s flexible and can increase or decrease its generation almost instantly when needed, unlike coal or nuclear power. These latter two sources have a lot of fuel on site and are usually immune to interference but are slow to change performance. They are therefore considered to be base load power sources. Natural gas is very flexible, but because its fuel is pipelined when needed, it is prone to disruptions in supply. The weather in Texas was so bad that on February 15th, the coldest day, even some nuclear and coal-fired power plants were affected.
As Figure 1 shows, the natural gas rose to make up for the wind loss. In fact, it rose 450%, as shown in Figure 3 from the Wall Street Journal on Feb.17.
So the sequence of events was that wind turbines iced up from February 8th to 10th and their output dropped by 93%. Natural gas rose quickly to meet the shortage and increased a staggering 450%, but the pipelines that fueled it iced over, especially the valves on the pipelines, and put the natural gas generators out of service.
If the Texas grid generation mix had more coal and nuclear power, this problem would have been much less in cold weather. However, coal and nuclear power plants have been shut down to make way for more wind power. To make matters worse, some coal and nuclear power plants have had cold weather issues themselves.
Conclusions
The immediate cause of the collapse of the Texas power grid was the very cold weather from February 9th to 17th. The initial problem was that the wind produced over 25% of Texas’s electricity and occurs intermittently. Knowing it was intermittent, ERCOT increased natural gas production as an instant backup to the wind, but forgot that natural gas is available on demand and the pipelines are prone to disaster, especially in cold weather. Disaster power sources are coal and nuclear, they have fuel on site for days or weeks and do not require a pipeline or backup.
Political Implications
Texas has promoted the construction of wind turbines. They do this in coordination with the US government through direct subsidies and by paying for wind generation rather than for electricity purchased. This sales guarantee means that the producer companies do not have to take market demand into account, but can build wind turbines endlessly and without risk. They can even pay others to take their power and then be refunded by the government with our taxpayers’ money! Since 2006, federal and Texas subsidies for wind power totaled $ 80 billion. This stupidity is well explained on the stopthesethings website.
Wind overcapacity has distorted the Texas generation mix to dangerous and unbalanced levels. Natural gas, coal and nuclear power plants have too little income to expand or fortify their facilities, as wind can generate as much as it wants and income is guaranteed for the electricity generated.
The subsidies and mandates must be stopped and our base load capacity (also known as emergency capacity) increased and strengthened. The production of coal and nuclear power must increase. It should be clear to everyone by now that while natural gas is a perfect minute by minute grid stabilizer as it is an on-demand power generator, it is prone to weather disruption. The current base load capacity in Texas is too small and too fragile.
Politics has thoroughly corrupted climate science, as I explain in my new book: Politics and Climate Science: A Story. The thoroughly corrupt field of climate science policy is now corrupting the areas of technology involved in generating electricity. It’s dangerous, engineers have to make technical decisions, not politicians. Reliable electricity is essential to our prosperity and well-being. Our various governments shouldn’t deliberately destabilize our power grid with silly renewable energy policies. You should strengthen the power grid to make Texas more resilient.
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