The state of Texas…

Austin, TX, 15 January 2024

A cold snap has raised concerns once more about security of electricity supply in Texas. Our energy editor, John Constable, happens to be travelling there and reports at first hand.

Figure 1: A screenshot of the Electricity Reliability Council of Texas web dashboard at 07.45 Central Time, 15 January 2024:

The condition of the electricity grid in Texas has been a subject of real interest to energy policy analysts around the world for some time, due to its very heavy commitment to both wind (approx. 38 GW of capacity) and solar (approx. 19.5 GW) generation, a matter that was brought into sharp focus by the crisis of February 2021 when a winter storm caused blackouts in which some 4.5 million households lost supply with  about $195 billion dollars of property damage. The gas grid also failed. Fifty-seven people lost their lives.

It was objectively extraordinary that so prosperous and proud a state as Texas, which is said to be the 8th largest economy in the world on the basis of its $2.4 trillion annual GDP, could be forced into a crisis by cold weather that while severe was not unprecedented.

Naïve critics of renewables attempted to pin the blame on wind as the proximal cause of the blackouts, which was a gift to green apologists since in fact all types of generation plant failed, and there were many other contributory factors such as transmission line collapses, low levels of natural gas storage, and errors in the weather forecasting. The resulting muddled discussion was inconclusive, a fact that should come as no surprise to anyone who has looked deeply into electricity system failures, which typically result from a broad number of coincidental problems trigged by a single exogenous event. The UK blackout of August 2019, which resulted in a loss of supply to 1 million customers, mostly in the London area, is a case in point. A lightning strike on a grid line, a common event, was the proximal “cause”, resulting in generator trips, both conventional and renewable. Proximal blame could not be decisively pinned on any technology. The underlying problem was the fact that the system had become so fragile that such a normal event as a lightning strike could cause a broad failure of supply. Robust systems ride through such events or so contain the problems that they are only local failures; weak systems, on the other hand, suffer wide areas of failure and sometimes total collapse. This weakness is the UK system was the long term outcome of renewables policies that discouraged the construction and operation of conventional plant needed to guarantee of supply and render the system robust. The fact that the diagnosis is subtle does not make it any the less true. (See my Brink of Darkness: Britain’s Fragile Power Grid (2020) for more detailed discussions.)

Texas is currently facing yet another period of low temperatures, provoking the New York Times to raise raise doubts about the system once more: “Texas Says its Power Grid is Strong: It’s about to get tested” (13.01.24)

As with other systems that have adopted wind and solar in bulk, security of supply of Texas is in fact underpinned by conventional capacity. This snapshot of the system taken from the ERCOT as I write illustrates the point:

Figure 2:  Texas generation fuel mix, 08.19 CT, 15 January 2024. Screenshot from the ERCOT webs dashboard: https://www.ercot.com/gridmktinfo/dashboards

Total system load is about 75 GW (for comparison peak load in the UK is approximately 50 to 60 GW). Of this peak, Texan wind is contributing about 5.2 GW, from a total capacity of 38 GW, and solar a small fraction of its capacity. The bulk of the heavy lifting and the provision of inertia is being done by natural gas (65%), coal (17.5%) and nuclear (7%), all thermodynamically competent sources with a high degree of round the clock reliability and dispatchability. Indeed, the dispatchable operating reserves are largely to be found in gas-fired generation, of which there is nearly 68 GW in total, with 47.8 GW generating as I write.

While the picture looks reasonably sound, ERCOT has very sensibly issued a “Conservation Appeal” (see Fig. 1 above), requesting consumers to reduce demand if safe to do so. A reserve margin of 6.5 GW, less than 10% of load is not quite sufficient to banish all concerns when a severe weather event is in progress.

But how has Texas, of all places, found itself in a position of comparative weakness, and an object of condescending pity in the New York Times?

Part of the explanation is that the state is a victim of its own success. Largely due to internal migration within the United States, the population is rising and the economy is growing, and peak demand is consequently also rising. In 2000, peak demand was 58 GW, in 2010 65 GW, in 2020 74 GW, and in 2022 a striking 80 GW. It would seem that Texas is a great place to live and do business.

But that rising demand is not resulting in major increases in the conventional capacity which, as we have already noted, continues to guarantee security of supply. The growth is in non-dispatchable wind and solar. As a result, Texas, like other similarly committed systems such as the UK, has a large generation fleet, about 150 GW in total nameplate capacity, giving a comfortable apparent margin over demand that does not materialise in actuality, and is in fact largely absent at times of stress such as inclement weather conditions. In other words, the productivity of the system has been degraded by underutilised wind and solar capacity, with little or no augmentation of security of supply. As in the UK, this is a recipe for high consumer cost, and anxiety every time the weather is unfriendly.

With luck, Texas will not suffer another blackout this winter, and many of the contributory factors that were such a problem in 2021 have, it is claimed, been dealt with. But only the very innocent would interpret this as indicating that wind and solar are “working” for Texans. Texas is beginning to look like a chronically expensive and fragile system on the European model. Do Texans want that? Outside the city of Austin, the blueberry in a bowl of tomato soup as they call it here, I think not. Push is not yet coming to shove in Texas, but shove, like winter, is surely coming.