AbstractThe Bonneville Power Administration uses system dynamics to assist in its analysis of conservation policies for the Pacific Northwest electric system. This article describes the system dynamics models—the Conservation Policy Analysis Models—and explains why they are useful. After briefly describing model design and assumptions, the article gives examples of model application. One example involves simulation studies of a hypothetical policy by contractors. The second example involves Bonneville's own study of policies under consideration in the 1986 resource strategy. Key features that have made the models useful at Bonneville are no