Also from the CNN article:
The energy crisis in Texas raises also questions about the nature of the state's deregulated and decentralized electric grid. Unlike other states, Texas has made a conscious decision to isolate its grid from the rest of the country.
That means that when things are running smoothly, Texas can't export excess power to neighboring states. And in the current crisis, it can't import power either.
"When it comes to electricity, what happens in Texas stays in Texas," Cohan said. "That has really come back to bite us."