Cycle & save computer system

In June of 1981 the Tennessee Valley Authority began operation of its first large-scale load management program. This program, called Cycle & Save, manages electrical demand in residences and small commercial and industrial establishments by utilizing direct radio control of air-conditioners and water heaters.TVA obtained the right to interrupt service during certain hours of the day to the air-conditioners and water heaters of customers who volunteered for the program. As TVA's cost of operation rises above a predetermined economic threshold during peak demand hours, electrical service is temporarily curtailed to the water heaters and is reduced by up to 25 percent to air-conditioners.The scheduling of this new load management program's operation was controlled by six small computers located in five different cities in the TVA service area. The computers were part of an original equipment purchase from Motorola, Inc., for radio receivers, FM transmission equipment, and control computers with specially designed software.This software and hardware system is the subject of this paper. It will describe how the computers are used to optimize the benefits of load management of end-use devices to the TVA power system.