He must have used an ENORMOUS amount of electricity to have a $17k bill. In fact the math doesn't even make sense. At $9 per kw/hr, it means he used 1800 kw/hr over a few days, which shouldn't even be possible. A typical house uses 20 kw/hr per day, so how is he using over 400 per day? Is he running a grow house or something?
Wholesale natural gas prices at some point during the storm spiked to ~$1000/MMBtu. If their contracts were linked directly to wholesale prices they would've experienced the higher rates