Increasing concerns regarding the impact of CO2 production from the electric power system on global climate and heightened prospects of mandatory controls on the production of CO2, led the Council in the summer of 2006 to request a forecast of the CO2 produced from alternative future resource portfolios. Four scenarios were identified: the recommended resource portfolio of the Fifth Power Plan (the base case), a low-conservation scenario in which the conservation targets of the Fifth Power Plan are not achieved, a high-renewables scenario based on state renewable energy portfolio standards, and a scenario based on the resource acquisition recommendations of utilities’ integrated resource plans. Two additional sets of studies were subsequently requested: 1) the CO2 effects of removing the federal dams on the lower Snake River; and 2) the CO2 effects of summer spill at the lower Snake River and lower Columbia River dams.
The purpose of these alternative scenarios is to quantify the sensitivity of results to plausible changes in the power system and to some related policies that have received attention. No new Council position on any of these policies is intended by this analysis, nor should any be inferred.