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No, Wind Turbines Didn't Keep Texas Grid Online

Wind energy kept Texas powered earlier this week, according to supporters of the renewable energy power source.

Plunging temperatures as a result of the polar vortex pushed energy generation across the country above normal winter levels, including Texas:

ERCOT said demand for electricity today reached 55,486 megawatts between 7 a.m. and 8 a.m. That’s short of the record winter demand of 57,265 on Feb. 10, 2011, which produced rotating outages, and lower than peak demand during last month’s run of low temperatures, said ERCOT spokeswoman Robbie Searcy.

The demand for electricity in Texas nearly pushed the grid to begin triggering rolling power outages:

The Electric Reliability Council of Texas (ERCOT), which manages the electric grid in most of Texas, briefly issued an Energy Emergency Alert 2 early Monday morning, the last step before rotating power outages would be implemented. ERCOT canceled the warning about possible outages shortly after 9:30 a.m.

But the loss of just one more large power plant could have pushed the grid over the edge, Dan Woodfin, ERCOT director of system operations, told reporters on a conference call. The grid lost two big power plants to weather-related problems and some others to other problems, totaling about 3,700 megawatts of power, Woodfin said.

Texas made up the deficit between demand and supply by tapping energy sources outside the state:

During that time, the state imported about 800 megawatts from the nation’s eastern power grid, and another 180 megawatts from Mexico. A megawatt is roughly enough to supply about 200 Texas homes during a period of peak electricity use, although demand in Texas peaks during the summer as air conditioners fire up.

For about an hour during the emergency alert period, wholesale power prices hit the state’s regulatory ceiling of $5,000 per megawatt-hour, Woodfin said. That’s about 100 times the $50 per megawatt-hour price generally seen.

Why did Texas need to seek out of state electricity when, as was trumpeted by wind energy supporters, wind was filling in?

Wind could not fill the gap created by increased demand from the cold and the drop in capacity due to outages from plants–both scheduled and unscheduled.

The Energy Reliability Council of Texas monitors the production of wind energy in the Texas grid and produces daily “wind integration reports” (WIR) that carefully illustrate:

Hourly averages of actual ERCOT load vs. wind output, and total installed wind capacity
Actual average wind output as a percentage of the total installed wind capacity
Actual average wind output as a percentage of the ERCOT load
Weekly graph of the ERCOT load vs. actual wind output

The first graph from the January 6 WIR shows that at the very moment energy demand in Texas began to increase in the early morning hours Monday, actual wind output began to plummet precipitously.

Wind production falls well below 2,000 MW and remains there for most of the rest of the daylight hours on Monday, picking up again only as night returns:
ERCOT Load vs Wind Input2

In the next graph, ERCOT’s detailed hourly picture shows wind output falling below 20 percent of installed capacity by 7am, the same hour as power plants totaling 1,350 MW went offline.

Actual Wind Output as Percentage of Installed Wind Capacity

Actual wind output as a percentage of ERCOT’s total load declined from approximately 15 percent at midnight to around just 5 percent by 7am, as the peak of the surge of demand was felt, and remained below the 10 percent threshold until after 11pm Monday.

Actual Wind Output as Percentage of ERCOT Load

So, instead of bailing out the Texas grid, the intermittent source was reduced to a trickle on a near-record setting day for the state of Texas.

The Institute for Energy Research found the same results:

But even though early morning is generally a good time for wind generation, on Monday morning only 17 percent of ERCOT’s wind capacity (1,782 megawatts of the approximately 10,400 megawatts of wind capacity) were operating at that time. According to Fuel Fix, this means that “on Monday [wind] only contributed about 3.2 percent of electricity used during peak demand. It is obviously a judgment call whether 17 percent of capacity and 3.2 percent of total generation is indeed “massive quantities” of wind or merely middling amounts.

Winter energy demand is lower than summer peak demand–when Texans reasonably clamor for air conditioning–and more than 10,000 MW of generation for the state’s grid was offline Monday for routine, scheduled maintenance:

Electric supplies on Monday tightened after more than 3,700 megawatts of generation was forced to shut overnight Sunday and early Monday, Dan Woodfin, ERCOT’s director of system operations, told reporters. The forced outages came on top of nearly 10,000 MW of generation that was already shut for the season or for planned maintenance, he said.

Woodfin said about 1,800 MW of the 3,700 MW of the forced outages were weather-related, including two large power plants in north central Texas that he declined to name.

The American Wind Energy Association was quick to tout wind’s contributions:

Then in Texas, the more than 2,000 MW of wind output on Monday morning was the critical difference keeping heaters running as the grid operator struggled with numerous outages at conventional power plants. More than 13,000 MW of conventional power plants were down for maintenance, while another 2,000 MW of conventional power plants experienced unplanned outages, forcing the grid operator to resort to emergency procedures. In a similar incident two years ago, wind energy earned accolades from the grid operator for helping to keep the lights on as dozens of conventional power plants failed in another cold snap.

Other outlets like ThinkProgress, also pushed wind’s contributions.

“Demand remained high on Tuesday, but increased output from West Texas wind farms enabled the state to avoid an emergency scenario,” said ClimateProgress, TP’s climate blog.

Even Al Armendariz, the former Environmental Protection Agency regional director whose promises to “crucify” oil and gas producers resulted in his abrupt resignation, joined in congratulating wind:

Calling coal, gas, and nuclear “unreliable” Armendariz dinged the “old stuff” of traditional power generation–the Luminant Comanche Peak 1 nuclear was at 72 percent of capacity, according to Reuters, both Monday and Tuesday–while neglecting to mention that all day Monday, actual wind output for ERCOT as a percentage of total wind capacity never even managed to reach 70 percent during any one hour, and fell short of 50 percent in at least 20 of the 24 hours that day, according to ERCOT’s reports.

Armendariz currently works for the Sierra Club’s “Beyond Coal” campaign.