You could try to sue for negligence or not informing customers or whatever. But they simply are not gouging.
Edit: Also, I didn't appreciate that this wasn't even a market spike. The Texas government literally set a ludicrously high price, to try to boost supply:
> Texas’ Public Utility Commission, appointed by Abbott, raised the wholesale market price of electricity to $9 per kilo-watt hour — a 7,400% increase over the average 12 cents per kilo-watt hour — in response to rising demand. The hope was power generators would be enticed to produce more electricity.
So the charge is even more ridiculous that it first appears. Griddy is literally passing on the price set by the state government — and which they in turn were paying to suppliers.