Michael Sivak shows us the numbers.
The energy used to heat interior spaces accounts for the largest share of residential energy consumption throughout most of the United States. The exceptions are parts of the south where air conditioning dominates and parts of the southwest where, surprisingly, water heating dominates.
In the United States, residential energy consumption accounts for 20% of all energy used. This analysis focused on how locale climate affects the distribution of residential energy for various uses.The Department of Energy divides the United States into eight climate regions: Hot-humid, Mixed-humid, Hot-dry, Mixed-dry, Cold, Very cold, Marine, and Subarctic. The map below shows seven of these eight climate regions. (The eighth region, Subarctic, is confined to only a portion of Alaska. The rest of Alaska is in the Very cold region, while Hawaii is in the Hot-humid region.)
The raw data for this analysis came from the Residential Energy Consumption Survey (administered by the Energy Information Administration) and are applicable to 2015. The Residential Energy Consumption Survey provides breakdowns by end uses for all climate regions except for Subarctic. However, the survey combines the Cold and Very cold regions into one, as well as the Hot-dry and Mixed-dry regions. Therefore, data were available for a total of five climate regions.
The first entry row in the table below lists the data for all homes combined. The average total energy consumption for all homes in the United States in 2015 was 77.1 million Btu per household. Space heating was responsible for the largest share of residential energy use (46%), followed by water heating (19%) and air conditioning (9%), which used only about a fifth of the energy for space heating. Lower users of energy were lighting (5%) and refrigeration (3%). Below the entries for all homes combined are the data for the five examined climate regions, rank-ordered by the average total household consumption.
The region with the greatest average energy consumption was Cold/Very cold, followed by Mixed-humid, Hot-humid, Marine, and Hot-dry/Mixed-dry. The average energy consumption in the Cold/Very cold region was 82% greater than in the Hot-dry/Mixed-dry region (94.2 vs. 51.8 million Btu per household).
Space heating was the main user of residential energy in the two regions with the greatest total energy consumption—Cold/Very cold and Mixed-humid—as well as in the Marine region. Air conditioning was the main user of energy in one region (Hot-humid), while water heating was the main user of energy in the region with the smallest total energy consumption (Hot-dry/Mixed-dry).
Michael Sivak is the managing director of Sivak Applied Research and the former director of Sustainable Worldwide Transportation at the University of Michigan.