On the Equilibrium Dynamics of Demand Response in Thermostatic Loads

Demand response is expected to play a crucial role in many aspects of "smart grid" technologies being examined in recently undertaken demonstration projects. The behavior of load as it is affected by load control strategies is key to understanding the degree to which various classes of end-use load can contribute to demand response programs at various times. This paper examines a simple case in an effort to illustrate how subtle changes in the consumer behavior that drives demand can have dramatic impacts on the diversity of load and consequently the effectiveness of demand response programs. The example studied here uses electric water heaters to illustrate not only the complexity of the problem, but also the significance of the effect. This example can be readily extended to other end-use devices, such as air-conditioners, heat pumps, and electric vehicle chargers.