Transmission Needed for Decarbonization

Decarbonization studies suggest we need to expand our current transmission system by 50%–210%, but today's project pipeline would add only 11%–12% to the system.

Note: “Current system” and “Current pipeline” are based on Americans for a Clean Energy Grid (April 2021).

“100% clean electricity, limited load growth” is based on scenarios from Vibrant Clean Energy (December 2020) and Brown & Botterud (January 2021); they are (from bottom to top): VCE CE (95% emissions reductions from 1990 levels by 2050 in the US power sector, without co-optimization of distributed energy resources), VCE CE-DER (same as VCE CE, but with co-optimization of distributed energy resources) and B&B USA + AC +DC (achieving 100% renewable energy supply in the US power sector with only commercial technologies, allowing build-out of new and existing AC and DC transmission within and between regions).

“Economy-wide decarbonization” is based on scenarios from Princeton (October 2021); they are (from bottom to top): Princeton E+ RE- (fully decarbonizing the entire US economy, assuming aggressive end-use electrification but constrained wind and solar buildout) and Princeton E+ (same as Princeton E+ R- but without constrained build rates).