Yes, I see, it says megawatt hour. So that means they are charging $3 per KWH?
That is the wholesale rate for short-term peak demand. That cost is passed to the consumers in various rate plans. During that peak time only a small portion is bought at that rate meaning the average price only goes up a small amount. That and the freeze only lasted a couple of days and the customer would only see a small increase in his monthly bill. But it gets big headlines ...