Princeton University’s Zero Lab REPEAT Project

The report assesses the role of electricity transmission in enabling the full emissions reduction potential of the Inflation Reduction Act (IRA).

Previously, REPEAT Project estimated that IRA could cut U.S. greenhouse gas emissions by roughly one billion tons per year in 2030 and reduce cumulative greenhouse gas emissions by 6.3 billion tons of CO2-equivalent over the decade (2023-2032).1 That outcome depends on more than doubling the historical pace of electricity transmission expansion over the last decade in order to interconnect new renewable resources at sufficient pace and meet growing demand from electric vehicles, heat pumps, and other electrification.

While our modeling finds this outcome makes economic sense, current transmission planning, siting, permitting and cost allocation practices can all potentially impede the real-world pace of transmission expansion. We thus model the impact of constrained growth in U.S. electricity transmission on emissions outcomes and the pace of renewable electricity expansion under IRA.


1 Jenkins, J.D., et al., “Preliminary Report: The Climate and Energy Impacts of the Inflation Reduction Act of 2022 ,” REPEAT Project, Princeton, NJ, August 2022. DOI: 10.5281/zenodo.6992940