Approaches for Benchmarking Energy Performance

1
Approaches for Benchmarking Energy Performance

• by Terry Sharp
• ASHRAE Winter Meeting - 2002

http//www.energystar.gov/ http//eber.ed.ornl.gov
/benchmark/
2
Benchmarking Approaches

• Averages
• Medians
• Simple Ranking
• Normalized Ranking

3
Distributions of Building Energy Use Intensities
(EUIs) Are Skewed
4
EUIs Averages Versus Medians
71
69
69
80
64
54
60
Location in
40
Distribution
()
20
0
Educ.
Office
Lodge
Health
Food
50
50
50
50
50
Median EUI
69
69
71
54
64
Average EUI
5
Distributions of Building Energy Use Intensities
(EUIs) Are Skewed
6
A Cumulative Distribution of Building EUIs Can Be
Used to Rank
7
A Cumulative Distribution Can Serve as a Rating
Tool
8
Building Operational Characteristics Impact
Energy Use Intensity
9
Drivers of Energy Use
10
A Cumulative Distribution Can Serve as a Rating
Tool
Rating

100
80
60
40
20
0
0
50
100
150
200
Energy Use Intensity (kBtu/sf-yr)
11
Site and Source Energy Use Conversions

• Site basis
• 1 kWh 3.412 Btu
• Source basis
• 1 kWh 3.412 x 3.02 10.3 Btu

12
For Comparisons, Understanding Site and Source
Energy Is Critical
Rating

80
-- Part electric
40
All electric --
0
Energy Use Intensity (kBtu/sf-yr)
13
Summary

• Beware averages
• Simple ranking by EUI is a good approximation for
  comparisons
• Ranking where important secondary drivers are
  accounted for is best
• Limited and simple data needed
• Tools can provide rapid snapshot of cost
  reduction / improvement potential