Exploring the impact of energy efficiency as a carbon mitigation strategy in the U.S.

We conclude that the clean power transformation can be made more affordable by improving the efficiency of energy utilization. By downscaling the expansion of natural gas plants, energy efficiency can also avoid legacy impacts. While strong energy-efficiency policies lower overall CO2 emissions, coal plant retirements can be delayed, postponing associated local air quality benefits. Thus, we illustrate a limitation of single-pollutant policies while also demonstrating the value of co-optimizing demand- and supply-side carbon mitigation options.