The Effect of Natural Gas Supply on US Renewable Energy and Greenhouse Gas Emissions

Thursday, 18 December 2014
Christine Shearer, University of California Irvine, Irvine, CA, United States, John Bistline, Stanford University, Los Altos Hills, CA, United States, Mason Inman, Near Zero, Seattle, WA, United States and Steven J Davis, University California Irvine, Irvine, CA, United States
Increased use of natural gas has been promoted as a means of decarbonizing the US power sector, because of superior generator efficiency and lower CO2 emissions per unit of electricity than coal. We model the effect of different gas supplies on the US power sector and greenhouse gas (GHG) emissions. Across a range of climate policies, we find that more abundant natural gas decreases use of both coal and renewable energy technologies in the future. Without a climate policy, overall energy use also increases as the gas supply increases. With reduced deployment of lower‑carbon renewable energies and increased electricity consumption, the effect of higher gas supplies on GHG emissions is small: cumulative emissions 2013-2055 in our high gas supply scenario are 2% less than in our low gas supply scenario, when there are no new climate policies and a methane leakage rate of 1.5% is assumed. Assuming leakage rates of 0 or 3% does not substantially alter this finding. In our results, only climate policies bring about a significant reduction in future CO2 emissions within the US electricity sector. Our results suggest that without strong limits on GHG emissions or policies that explicitly encourage renewable energy, more abundant natural gas may actually slow the process of decarbonization, primarily by delaying deployment of renewable energy technologies.