Stakeholders often have competing interests when selecting or planning new power plants. The purpose of developing this preliminary Electricity Portfolio Simulation Model (EPSim) is to provide a first cut, dynamic methodology and approach to this problem, that can subsequently be refined and validated, that may help energy planners, policy makers, and energy students better understand the tradeoffs associated with competing electricity portfolios. EPSim allows the user to explore competing electricity portfolios annually from 2002 to 2025 in terms of five different criteria: cost, environmental impacts, energy dependence, health and safety, and sustainability. Four additional criteria (infrastructure vulnerability, service limitations, policy needs and science and technology needs) may be added in future versions of the model. Using an analytic hierarchy process (AHP) approach, users or groups of users apply weights to each of the criteria. The default energy assumptions of the model mimic Department of Energy's (DOE) electricity portfolio to 2025 (EIA, 2005). At any time, the user can compare alternative portfolios to this reference case portfolio.3 Two alternative portfolios are compared to the reference portfolio in 2010: the zero coal portfolio and the zero energy dependence portfolio. The main effect of removing coal combustion from the portfolio in 2010 is cost--the overall levelized cost of the portfolio increases from 2.85 cents/kWhr to 4.35 cents/kWhr ($2003), total emissions of key pollutants, including carbon, drop by 1.66 trillion tons, and dependency, measured in terms of amount of oil and natural gas in the electricity sector, increases from 4.2% to 16.3%. The portfolio also becomes slightly safer in terms of worker deaths and less sustainable in terms of the depletion rate of domestic fossil fuel reserves.Despite the elimination of any imported oil or natural gas in the electricity sector in the second alternative portfolio discussed here (the zero energy dependence portfolio), U.S. imports of petroleum are barely affected; removing all petroleum from the electricity sector only decreases U.S. oil import rate from 57.9% to 56.9% in 2010. In terms of future work, EPSim would benefit from a number of enhancements, including adding four additional criteria, expanded definitions of currently completed criteria, and rigorous review and testing in small groups.