As winter storm bore down onto Texas millions of power customers lost power. Not to be outdone political pundits took the opportunity to blame specific power sources. We dig into the numbers and find out.
The unprecedented winter storm brought extreme low temperatures and snow to Texas not seen in over 100 years. These extreme conditions forced nearly one third of the power normally generated to come off line in the form of freezing lines, freezing sensors, freezing windmills and dropping pressure needed in some natural gas lines. In addition, demand spiked due to the falling temperatures as thermostats were turned on or up.
We compiled the data on the power composition of the power sources of power for ERCOT, The Electric Reliability Council of Texas on a normal day and compared this to the power sources and their relative outages during the winter storm so identify which power sources were responsible for what percentage of the outages.
ERCOT’s power is compromised of mixture of Natural Gas & Coal (66%), Nuclear (5%), Wind (23%), Solar (4%) and various other sources such as petroleum (2%). During the storm it was reported that 1/3 of the outage was due to wind (frozen windmills) and 2/3’s due to coal, gas and nuclear malfunctions related to the cold. In addition, there was a 14% increase in demand due to the cold.
This equates to 20% of the outage due to the coal, natural gas and nuclear malfunctions and wind malfunction due to 10% of the outage, with 14% of the outage due to demand over anticipated peak. While coal, natural gas and nuclear are responsible for 20% of the outage these sources are responsible for 71% of the normal power generation resulting in a 28% failure rate. Wind is responsible for 23% of the power generated and was responsible for 11% of the outage resulting gin a 43% failure rate or approx. 50% larger failure rate.
Reviewing these computations we find that the wind failures were relatively more failure prone. That being said, we feel it would be dishonest to rate any single source as the cause of the failures, especially considering the event was a weather event which can be especially unpredictable, both on a large scale (considering the unpresented nature of the storm) and on the granular level (conditions could be very different from power station to power station).