Texas power prices soar 20,000% as brutal heat wave sets off emergency

Spot electricity prices topped $ 5,000 per megawatt-hour, up more than 200 times from Wednesday morning .

The state's grid operator issued its second -highest energy emergency, then later said conditions returned to normal.

The Biden administration declared a power emergency in Texas on Thursday , waiving some air-pollution rules so generators in the state could produce more electricity.