Widespread power outages that swept across Texas and parts of New Mexico this week due to extreme cold in the region can be traced back to supply chain failures involving both natural gas and renewable energy sources.

On Wednesday, 28,000 megawatts of thermal energy generation, which includes gas, coal and nuclear plants, was offline in Texas compared to 18,000 megawatts of renewable energy generation.

Dan Woodfin, the Senior Director of System Operation with the Electric Reliability Council of Texas (ERCT) relayed those numbers to reporters during a press briefing.

“In different ways the very cold weather and snow has impacted every type of generator,” Woodfin said.

To prevent damage, about half of the fleet of wind turbines in Texas had to be taken offline due to icing on the blade, Woodfin said.

Texas Governor Greg Abbott on Fox News on Tuesday blamed the “shutdown” of solar and wind energy for Texas’s inability to generate enough power to meet the increase in demand.  “This shows how the Green New Deal would be a deadly deal for the United States of America,” Gov. Abbott said.  However, officials with ERCT said during the press briefing the following day that a lack of thermal energy generation, not renewable energy generation, is at the heart of the energy crisis.

There is some issue on the natural gas system as a whole. You’ve got freeze offs in the well heads, they’re cold so you’re not getting gas out of the ground into the pipeline system.

Dan Woodfin

A lack of winter weatherization for both renewable energy sources like wind turbines as well as thermal energy generators like gas, coal and nuclear, also contributed to the rolling power outages and energy crisis.

In northern states, thermal energy plants are typically housed within a building to help keep generators warm and to protect against winter conditions, Woodfin said. Likewise, renewable sources in the north are outfitted with upgrades that help them to operate better in the winter.

In Texas and most southern states, thermal generators are not contained within a building in order to maximize their output in the summer, when energy demand tends to peak.

“If you put a thermal generator in a building, you actually can’t get as much out of that generator, it can’t produce as much because it gets hotter in the building,” Woodfin said.

Because extreme cold is a rare occurrence in Texas, most of the wind turbines also do not have upgrades that would allow them to operate better in cold weather, Woodfin said.

ERCT President and Chief Executive Officer Bill Magness reiterated that both renewable and nonrenewable energy sources contributed to the energy shortages.

“Those generation units that came offline in the extraordinary weather were of all types,” Magness said. “We’re really just seeing the impacts of this weather event go across wind, solar, nuclear, gas—across the industry.”

In a Wednesday press release, the Lea County Electric Cooperative also cited disruptions to both gas and renewable energy generation as contributing to the power outages in the region.

“Because of the record-setting freezing weather, the demand for electricity in New Mexico & Texas is more significant than what can be produced at power plants,” the cooperative said in the release. “There is very limited output from the renewables due to icing on the wind turbines and overcast skies limiting the solar panels as well.”

With more than five days of below-freezing temperatures, water used power plants is limited because much of it is frozen, the cooperative said. “Natural gas has been in limited supply due to the weather conditions.”

Damage to power lines from winter storms has also led to some of the power outages in the Lea County area, the cooperative said.