Although numerous factors contributed to the polar vortex-induced energy crisis in Texas, the central role of natural gas — or lack thereof — was becoming increasingly clear Friday as temperatures began to rise and power was restored.

Ercot generation

The unprecedented cold snap drove Texas power demand to new winter peak records rivalling peak demand figures in the summer, which is normally when the state sees the biggest surge in consumption, said International Energy Agency (IEA) analysts Keith Everhart and Gergely Molnar. 

In a report published Thursday, the authors highlighted three main factors contributing to the extended power outages that left residents without heat and water, in some cases for days: much higher electricity demand, lower natural gas production and power generation...