The role of buildings in U.S. energy system decarbonization by mid-century
Full decarbonization of the U.S. energy system to meet climate goals requires aggressive emissions reductions across energy end uses; however, prevailing policies focus on end-use electrification and clean energy supply rather than a broader set of demand-side solutions. We assess multiple CO2 emissions reduction pathways to mid-century for U.S. buildings, which are among the largest sources of CO2 emissions across end-use sectors. We find potential for up to a 91% reduction in building CO2 emissions from 2005 levels by 2050 using a portfolio of efficiency, load flexibility, and electrification alongside rapid grid decarbonization. Demand-side measures could account for nearly half of overall emissions reductions, with building efficiency delivering more than double the emissions reductions of electrification measures in the near term. Further, building efficiency and flexibility would generate up to $122 billion in annual power system cost savings by 2050, offsetting nearly half the incremental cost of full grid decarbonization.