EIA explores effects of weather projections on energy consumption in buildings

Nearly half of the energy consumed in U.S. buildings in 2021 was used for heating and cooling, according to modeled estimates in our Annual Energy Outlook 2022 (AEO2022) Reference case. An Issues in Focus analysis on alternative weather assumptions highlights how different long-term weather projections affect space heating and space cooling demand in the U.S. residential and commercial sectors.

In the full analysis, we modified assumptions for future heating degree days (HDDs) and cooling degree days (CDDs)—indicators of space heating and space cooling energy demand, respectively—to show how those weather assumptions affect energy prices, electricity generation, and energy-related emissions.

In our Reference case, we assume that future heating and cooling degree days in each state follow a linear trend based on the previous 30 years. These state-level values are weighted by population to form census division and national values. We assume that the past trend of migrations to warmer and drier climates within the United States will continue. Cases in the analysis include assumptions based on warmer or cooler weather than in the Reference case, and they also contrast future trends based on using the previous 10 years instead of the previous 30 years of historical data.

In the Cooler case, consumption of energy in residential and commercial buildings in the United States is 12% higher in 2050 than in the Reference case because of increasing fossil fuel demand for space heating. In the Warmer case, demand for space cooling leads to 4% more purchased electricity consumption in buildings by 2050 compared with the Reference case.

Weather-driven changes to energy demand in U.S. buildings lead to variation in fuel prices in all sectors in these cases. U.S. average electricity prices are 8% higher in 2050 in the Warmer case than in the Reference case due, in part, to increased use of natural gas to meet generation demand from the electric power sector for space cooling in the summer. Average electricity prices are lower in the Cooler case than in the Reference case as a result of lower peak summer demand and differences in the mix of fuels used to generate that electricity.

More fossil fuel consumption in the Cooler case and 12% more delivered energy consumption in buildings by 2050 lead to 24% more direct carbon dioxide (CO₂) emissions from residential and commercial buildings in 2050 than in the Reference case. The Warmer case results in 5% less delivered energy consumption in buildings and 15% less direct CO₂ emissions from residential and commercial buildings.

Principal contributor: Kevin Jarzomski