An integrated electric utility planning model, the Resource Policy Screening Model (RPSM), was used to project acquisitions from independent power producers made by customers of a US power marketing authority, Bonneville Power Administration (BPA) markets power from darns in the Pacific Northwest to retail utilities, BPA＇s historical cost advantage has eroded and customers are evaluating more costly nonutility generation to meet future load growth, If some customers will pay a premium above BPA rates for power, how much load could BPA lose? Steps in the analysis are presented, RPSM is a system dynamics model used in energy policy studies since 1983, This study marked the first application for understanding effects of electric industry deregulation on BPA, RPSM was modified, potential nonutility supplies were forecast, and scenario simulations of acquisitions, loads and rates were performed for utilities in the region, Later, the study method was adapted for other uses at BPA.