Overview of a K-12 Utility
Benchmark Study and Survey
Supported by the Arkansas
Dept. of Education and the ADED – Energy Office
Darin W. Nutter, Ph.D., P.E.
Mechanical Engineering Department
University of Arkansas
[email protected]
1
Background
Arkansas public schools
• 463,000 Students
• 82 million square feet of building
space
• Annual utility expenditures
exceed $50 million



Concerns regarding recent
high utility prices and fixed
M&O budgets
Taxpayers pay 10 times the
cost of construction on M&O*
AEO pilot utility tracking
program
* California Energy Commission Report 400-03-019C, Sept, 2003
Outside Contract
Labor
5%
Other
8%
Equipment &
Supplies
8%
Payroll
48%
Energy/Utilities
31%
Percentage distribution of M&O budget.
American School and University, April, 2004
2
Pilot Utility Tracking Program






Water
Natural gas
Electricity
Trial online utility tracking efforts
Eight (8) participating districts
Completed Fall 2005
3
2005 Summer UA Mechanical
Engineering Internships
4
UA Project Objectives


Help schools with data entry and utilization
of online service
Perform first level evaluation of K-12 facility
usage characteristics
• Publish benchmark values for several parameters
related to building performance which can be
used as a point of reference
• Evaluate the potential for significant utility cost
reductions in Arkansas schools
• Determine the utility-related practices and
concerns at the district level
5
Part 1 – Benchmark Study
BENCHMARKING: measuring and comparing one’s performance
against the performance of similar organizations
Six Steps:
1. Identify key variables –$, electricity, NG, water
2. Select good comparable sources – EPA Energy Star,
DOE, AS&U. …
3. Collect and measure performance data
4. Normalize and adjust to meaningful data
5. Compare / analyze data
6. Prioritize, change, and improve performance
Yam, R., et al., Journal of Quality in Maintenance Engineering, v 6 n 4, 2000, p224-240
6
Data Collection

84 school campuses in 8 Arkansas school districts
•
•
•
•
•

56 Elementary (EL)
8 Middle School (MS)
10 Junior High (JH)
10 High School (HS)
452 total utility meters
Bills entered into online database
• Assistance from interns

Used data from May 2004 – April 2005
• Most consistent 12 months
• Monthly data compiled into annual values
7
Normalization
Normalized
• Usage, power, other
• per student
• per ft2 of building
area

Computed
•
•
•
•
mean,
25th percentile
75th percentile
school types
Total Energy per Unit Area (kBtu/ft2-yr)

120
EL
100
EL
80
JH
EL
EL
EL
JH
E
L
E
LHS
E
L
HS
HS
HS
E
L
JHS
H
JH
JH
EL
EL
LJH
LEHS
EE
LEL
EL
EL
LHS
LEMS
EE
LEL
EL
MS
EL
LMS
LEL
LE
LE
LE
LE
LE
EE
LE
HS
E
L
E
L
S
HEL
LJLM
LE
LE
LE
LE
LE
MJH
SEE
JH
EHS
LEL
EL
E
L
EL
HS
EL
EEL
LEL
JH
EMS
L
EL
EL
EL
AVERAGE
60
40
1999 CBECS
20
MS
EL
MS
0
0
10
20
30
40
50
60
70
80
School Number
8
90
Computed Benchmark Values
Table 1 Average, 25th percentile, and 75th percentile values for benchmarking parameters by school type
ELECTRICITY
kWh/ft2-yr
25th
School Type
Elementary
Middle School
Junior High
High School
Overall
75th
Percentile Average Percentile
8.76
8.27
9.22
9.39
8.88
6.94
6.44
7.64
8.06
7.11
5.13
4.62
6.06
6.73
5.34
NATURAL GAS
CCF/ft2-yr
25th
75th
Percentile Average Percentile
0.296
0.353
0.314
0.281
0.304
0.220
0.230
0.246
0.232
0.225
0.144
0.107
0.177
0.184
0.147
WATER
kgal/ft2-yr
25th
75th
Percentile Average Percentile
0.022
0.015
0.016
0.024
0.021
0.016
0.011
0.014
0.019
0.015
0.010
0.006
0.012
0.013
0.010
Also tabulated cost and
per student benchmarks
9
Normalization – Expenditures ($)

Total Utility Costs
• $0.81/ft2-yr
• $113/student-yr
Percentage of total utility costs
Water
13%
Natural Gas
29%
Electric
58%
10
Normalization – Electricity

Energy
•
•
•
•
•
•

$0.47/ft2-yr
$65/student-yr
24.3 kBtu/ft2-yr
CBECS 33.1 kBtu/ft2-yr
7.11 kwh/ft2-yr
993 kwh/student-yr
Demand (power)
• Study Median – 3.9 W/ft2
• CBECS Median – 4.3 W/ft2
11
Normalization – Natural Gas & Water

Natural Gas
•
•
•
•
•

$0.24/ft2-yr
$34/student-yr
22.5 kBtu/ft2-yr
CBECS 12.7 kBtu/ft2-yr
32.3 CCF/student-yr
Water
•
•
•
•
•
•
$0.11 /ft2-yr
$15/student-yr
15 gal/ft2-yr
2.12 kgal/student-yr
Little data for comparison in literature
Significant variation between schools
12
Part 1 – Overall Findings



Over 1/3rd of schools in the study were
below the 25th percentile in either
electricity, natural gas, or water
consumption per square foot of building
area
Ample benchmarks to evaluate Arkansas
schools (i.e., peer group comparison)
Currently looking at:
• equipment type and age
• weather influence
13
Part 2 – School District Survey



16 statements requiring Likert scale responses
1 open-ended question
Over 30% of districts responded
Statistically analyzed all data for:
• All districts combined
• Smaller districts (enrollment < 2000, 79%)
• Larger districts (enrollment ≥ 2000, 21%)
28000
2005/2006 AR K-12
District Enrollment
24000
20000
Enrollment

16000
12000
8000
4000
Enrollment = 2000
14
0
0
20 40 60 80 100 120 140 160 180 200 220 240 260
District
Survey Findings – All Districts



86% use buildings for community
activities
62% agree that it is difficult to track
costs between academic and nonacademic facilities
93% feel tracking utilities would be
beneficial
15
Survey Findings – All Districts


51% agree their district has
significant potential to reduce utility
costs
51% disagree that their local
utilities have helped conserve energy
and reduce utility costs
16
Survey Findings – CONTRAST

District utilizes automated building controls in
most of its buildings – Larger (65% agree),
Smaller (67% disagree)
100%
Small
Large
80%
60%
40%
“It is important to bring the
technologies and practices together …
specifically with the use of controls”
as related to flexible building use and
operations.
20%
By: Jean Lupinacci, U.S. EPA, ASHRAE panel on
Sustainability & the Building Environment, April 16, 2006
0%
SA/A
N
D/SD
Figure 3. Response by district size to Statement 2:
"Our school district utilizes automated
building controls in most of our buildings."
17
Survey Findings – CONTRAST


90% of large districts and 63% of small
districts carefully track utilities
Could the district use help tracking utilities?
– Larger (70% disagree), Smaller (73%
agree)
100%
Small
Large
80%
60%
40%
20%
0%
SA/A
N
D/SD
Figure 4. Response by district size to Statement 9:
"Our school district could use assistance
in tracking our utilities."
18
Survey Findings – CONTRAST


District could use additional or specialized
evaluation assistance to help conserve utilities and
reduce costs – Larger (40% agree), Smaller (77%
agree)
Maintenance and facilities operation personnel could
use more training related to optimal building
operation – Larger (45% agree), Smaller (81%
agree)
100%
Small
Large
80%
60%
40%
20%
0%
SA/A
N
D/SD
Figure 5. Response by district size to Statement 10:
"Our maintenance and facilities operation personnel could
use more training related to optimal building operations"
19
Survey Findings – CONTRAST

In planning for new buildings, capital costs are
more important than future costs – Larger
(60% disagree), Smaller (56% agree)
100%
Small
Large
80%
60%
40%
20%
0%
SA/A
N
D/SD
Figure 6. Response by district size to Statement 15:
"In Planning for new buildings, minimizing capital costs weigh
heavier on decision making than minimizing future utility costs."
20
Future Recommendations


Make available and further refine
benchmark parameters as a guide for
other school districts across the state.
Better understand the unique needs of
smaller school districts and applicable
technologies.
• Education
• Assistance
• Technology

Continue to utilize engineering students
to assist the state with
energy/environmental issues.
21
Questions?
22