ACEEE Blog, Mar. 22, 2017, by Brendon Baatz.
http://aceee.org/blog/2017/03/why-rate-design-matters-energy

"Today, most American households pay for electric service via a two-part electric rate. This typically consists of a small, fixed customer charge ($ per month) and an energy rate applied per unit of electricity ($ per kilowatt hour). There are some variations on this model, including energy rates that vary based on time of day or total monthly consumption, but the basic structure of residential rates hasn’t changed much over time. In recent years, utilities have proposed significant departures to this format to address the changing dynamics of the electric utility industry."