  In this paper, we study the price responsiveness of electricity consumption
from empirical commercial and industrial load data obtained from Texas.
Employing a dynamical system perspective, we show that price responsive demand
can be modeled as a hybrid of a Hammerstein model with delay following a price
surge, and a linear ARX model under moderate price changes. It is observed that
electricity consumption therefore has unique characteristics including (1)
qualitatively distinct response between moderate and extremely high prices; and
(2) a time delay associated with the response to high prices. It is shown that
these observed features may render traditional approaches to demand response
and retail pricing based on classical economic theories ineffective. In
particular, ultimate real-time retail pricing may be limitedly beneficial than
as considered in classical economic theories.
