March 16, 2020

The U.S. Energy Information Administration (EIA) projects that delivered energy for air conditioning will increase more than any other end use in residential and commercial buildings (also known as the buildings sector) through 2050, while energy consumption for space heating will decline. Higher residential and commercial energy consumption for air conditioning and lower energy consumption for space heating result from projected population shifts from colder to warmer parts of the United States, assumptions of warmer weather, and regional differences in sector growth.
In 2019, space heating accounted for 38% of delivered energy in buildings, a larger share than any other end use. EIA projects that from 2019 to 2050, delivered energy consumed for space heating will fall by more than 1.5 quadrillion British thermal units—the largest decline among end uses in both absolute terms and percentage terms. Total consumption of delivered energy by the buildings sector will increase by 7% as growing demand for end uses, including air conditioning, electronics, and water heating, more than offsets declines in energy consumption for heating and lighting.
Across the buildings sector, purchased electricity accounted for 94% of delivered energy for air conditioning in 2019. A wider variety of fuels met space heating needs. Natural gas was by far the most common fuel for space heating, accounting for about 70% of energy consumed for space heating in 2019. Smaller shares of wood, distillate, propane, and electricity also fuel heating equipment.
EIA projects that the United States will gain more than 58 million people and 24 million households by 2050 and that total square footage of U.S. residences will expand by 33%. By 2050, 71% of households will be in single-family homes, which typically have more air-conditioned floorspace than multifamily or mobile homes. These single-family homes will consume 86% of the energy used in U.S. residential air conditioning.
Based on population-weighted heating and cooling degree day data from the National Oceanic and Atmospheric Administration and U.S. Census Bureau population data, EIA estimates that in 2019, the United States experienced almost 4,300 weighted heating degree days and nearly 1,500 cooling degree days. The difference between these values largely explains why more energy is used for space heating than for air conditioning. EIA expects historical trends in population growth, regional population distribution, and average annual temperature to continue through 2050, and it expects the difference between population-weighted heating and cooling degree days to continue to narrow.
(Source and image: EIA)