by Michael Goggin, AWEA Manager of Transmission Policy
Many parts of the state of Texas experienced rolling blackouts today, coinciding with unusually cold temperatures across many parts of the state. Millions of customers statewide appear to have been affected.
It appears that wind energy was not in any way a cause of this event. In fact, wind energy actually played a major role in keeping the blackouts from becoming more severe: Between 5 and 7 a.m. this morning (the peak of the electricity shortage) wind energy was providing between 3,500 and 4,000 MW, roughly the amount it had been forecast and scheduled to provide. That is about 7% of the state's total electricity demand at that time, or enough for about 3 million average homes. While information about what is happening is still coming in, there appear to be several major causes:
1) Cold and icy conditions are causing unexpected equipment failures at power plants, and to a lesser extent on power lines themselves.
2) The cold temperatures are causing electric heating demand to exceed the demand expected for this time of year. Many fossil and nuclear power plants take planned outages during non-summer months for maintenance, since electric demand is usually lower during these periods than in the summer.
3) Unusually cold temperatures are driving very high demand for natural gas for heating, which may be straining the ability of the natural gas pipeline and distribution system to meet both these heating needs and the need to supply natural gas power plants (Texas obtains about half of its electricity by burning natural gas, and gas power plants account for about 70% of the state's generating capacity).
In all, 50 power plants totaling more than 7,000 MW have been lost due to the cold. It is unclear how many if any of these outages were caused by natural gas shortages – in many cases the outages appear to be due to the cold directly causing equipment failures like pipe breaks at power plants. Two coal-fired plants suffering pipe breaks accounted for a loss of up to 2,700 MW, a hefty chunk of the total. As of 2 p.m. Central Time, the rotating outages had ended. However, unusually cold temperatures are expected to persist through tomorrow, meaning outages may resume later tonight or tomorrow.