The EIA’s Annual Energy Outlook 2014 looks at several accelerated retirements cases that represent conditions leading to additional coal and nuclear plant retirements. CO2 emissions are significantly reduced when compared to the Reference case in side cases with accelerated coal retirements. CO2 emissions increase slightly in the Accelerated Nuclear Retirements case.
Natural gas and renewables are the primary replacements for lost capacity in each scenario.
Coal (74 percent) and natural gas (24 percent) power plants accounted for almost all of the CO2 emitted by the electric power sector in 2012.
The Accelerated Nuclear Retirements case projects CO2 emissions that are 4 percent higher compared with the Reference case in 2040. In this case, natural gas-fired generation is projected to be 13 percent higher than in the Reference case. However, renewables generation in the Accelerated Nuclear Retirements case increases 5 percent relative to the Reference case, which moderates the emissions impact. Coal generation does not differ significantly between the two cases.
Like in the Accelerated Nuclear Retirements case, natural gas generation makes up for most of the lost capacity in the Accelerated Coal Retirements case, resulting in a 19 percent increase in natural gas generation relative to the Reference case in 2040. However, because generation using natural gas emits less CO2 than coal, emissions decrease by 20 percent relative to the Reference case over that period. A 10 percent increase in renewable generation relative to the Reference case also serves to lower overall emissions.
Emissions are slightly higher in the combined Accelerated Coal and Nuclear Retirements case than in the Accelerated Coal Retirements case, because natural gas-fired generation replaces some nuclear power generation. However, the effect of the coal-fired capacity retirements keeps emissions 14 percent below the Reference case level in 2040.