New generation capacity investments may last for 60 years or more, during which time significant changes in policy and market conditions may occur. For example, a new gas-fired unit built today might face higher operating costs in the future if a CO2 policy were enacted, or if natural gas prices were to rise. How might future climate policy or gas price uncertainty influence the portfolio of new generation capacity assets built today? This technical update summarizes the results of research on this question by the Electric Power Research Institute’s (EPRI) Program 201-B.