Buildings consume 75% of U.S. electricity; therefore, improving the efficiency and flexibility
of building operations could increase the reliability and resilience of the rapidly-changing
electricity system. We estimate the technical potential near- and long-term impacts of best
available building efficiency and flexibility measures on annual electricity use and hourly demand
across the contiguous U.S. Co-deployment of building efficiency and flexibility avoids up
to 742 TWh of annual electricity use and 181 GW of daily net peak load in 2030, rising to 800
TWh and 208 GW by 2050; at least 59 GW and 69 GW of the peak reductions are dispatchable.
Implementing efficiency measures alongside flexibility measures reduces the potential for
off-peak load increases, underscoring limitations on load shifting in efficient buildings. Overall,
however, we find a substantial building-grid resource that could reduce future fossil-fired
generation needs while also reducing dependence on energy storage with increasing variable
renewable energy penetration.