Pacific Gas and Electric (PG&E) has recently added the voluntary Critical Peak Pricing (CPP) program that gives lower energy rates on non-CPP event days (non peak days) in exchange for higher rates on CPP event days. (high use Summer days)

You agree to pay higher peak rates of 60 cents a kilowatt-hour on no more than 15 days a year in exchange for a 3 cent discount on all other energy use times.

This is designed for businesses using more than 200 kW per month who can pull back energy use during peak days. The program has resulted in lower bills for some big customers like datacenters.