U.S. Commercial Buildings Energy Consumption and Intensity Trends: A Decomposition Approach

Transcription

1 U.S. Commercial Buildings Energy Consumption and Intensity Trends: A Decomposition Approach 31 st USAEE/IAEE North American Conference Behjat Hojjati, PhD Steve Wade, PhD November 5th, 2012 Austin, Texas U.S. Energy Information Administration Independent Statistics & Analysis v

2 Overview Introduction Data Source Overview of energy consumption Factors affecting energy consumption Methodology Results and Sensitivity of results to the choice in regions/categories 2

3 Commercial Buildings Energy Consumption Survey (CBECS) The only national-level survey on buildings characteristics and energy use CBECS includes all buildings >1000 square feet that are not residential, industrial, or agricultural with 50 percent or more commercial activity Multistage area probability statistical sample 3

4 Space heating and lighting accounted for over 55 percent of total energy use in 2003 Source: U.S. Energy Information Administration, Commercial Buildings Energy Consumption Survey,

5 Electricity gains as the main energy source in commercial buildings Source: U.S. Energy Information Administration, Commercial Buildings Energy Consumption Surveys, 1989 and

6 A wide variety of heterogeneous activities are performed in commercial buildings Assembly Education Food service Food sales Health care (inpatient) Lodging large offices (>50,000 square feet) Small offices (<=50,000 square feet) Mercantile and service Warehouse Other 6

7 Mercantile and service used more energy in 2003 Source: U.S. Energy Information Administration, Commercial Buildings Energy Consumption Surveys,

8 Between 1989 and 2003, average size of inpatient health care buildings grew faster than other types Source: U.S. Energy Information Administration, Commercial Buildings Energy Consumption Surveys, 1989 and

9 Growth in average size of buildings varied by Census region between 1989 and 2003 Source: U.S. Energy Information Administration, Commercial Buildings Energy Consumption Surveys, 1989 and

10 Energy intensity varied by building types in 2003 Source: U.S. Energy Information Administration, Commercial Buildings Energy Consumption Surveys,

11 Distribution of buildings shifted slightly towards the Midwest Source: U.S. Energy Information Administration, Commercial Buildings Energy Consumption Surveys, 1989 and

12 Aggregate energy intensity increased between 1989 and 2003 Energy consumption increased by 20.1 percent Total floorspace increased by 18.3 percent Energy intensity per square foot increased by 1.9 percent But aggregate intensity includes structural effects as well as efficiency and conservation changes. 12

13 Decomposition separates structural effects and produces intensity estimates better-related to the evolution of energy use in buildings Decomposition separates the impacts of three main effects and isolates structural changes from intensity Activity Structural Intensity E = BD * 11 BD SQFT E i * i Ei * = BD i = i = 1 BD BD SQFT i = 1 BD i i i = 1 E i 13

14 Results: Total Energy, Source: U.S. Computed from Energy Information Administration, Commercial Buildings Energy Consumption Surveys, 1989 and

15 Results: Total Electricity, Source: U.S. Computed from Energy Information Administration, Commercial Buildings Energy Consumption Surveys, 1989 and

16 Results: Total Natural Gas Space Heating, Source: Computed from U.S. Energy Information Administration, Commercial Buildings Energy Consumption Surveys, 1989 and

17 Results: Total Energy, and Source: Computed from U.S. Energy Information Administration, Commercial Buildings Energy Consumption Surveys, 1989, 1995, and

18 Results: Total Electricity, and Source: Computed from Energy Information Administration, Commercial Buildings Energy Consumption Surveys, 1989, 1995, and

19 Results: Total Natural Gas Space Heating, and Source: Computed from Energy Information Administration, Commercial Buildings Energy Consumption Surveys, 1989, 1995, and

20 Comparison Between Decomposed and Aggregate Intensity Source: Computed from U.S. Energy Information Administration, Commercial Buildings Energy Consumption Surveys, 1989 and

21 Thank You Behjat Hojjati Steve Wade U.S. Energy Information Administration 21