energy audit best practices 3rd annual e source major accounts training conference and summit may...
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Energy Audit Best Practices
3rd Annual E Source Major Accounts
Training Conference and Summit
May 9-11, 2007 Boston, Massachusetts
Kelly Kissock Ph.D. P.E.
Associate Professor
Department of Mechanical Engineering, University of Dayton, Dayton, Ohio
Principal: Go Sustainable Energy
GO Sustainable Energy
Energy Assessment Experience
• Director: University of Dayton Industrial Assessment Center– 25 no-cost assessments per year for mid-sized industries– Clients report saving average of $100,000 per year
• Director: University of Dayton Building Energy Center– Energy assessments and analysis for residential, commercial, and institutional
buildings• Principal: Go Sustainable Energy
– Energy assessments for commercial, industrial, institutional facilities:– Clients include Ford, Corning, Johns Manville, Cargill, Scotts, Delphi …
• U.S. D.O.E. Certified Qualified Specialist and Energy Expert– Compressed air– Process heating
• Trained energy consulting firms, utilities, industries and government agencies in US and abroad.
• Awards:– 2003 U.S. D.O.E Center of Excellence Award– 2006 Ohio Governors Award for Energy Excellence
Purposes of an Energy Audit
• Provide specific advice on current savings opportunities
• Educate client to help manage energy costs over long term
• Foster healthy and productive long-term relationship
Organizing an Audit
1) Preparation
2) Site visit
3) Analysis and reporting
4) Follow up
Preparation: Define Expectations
• Goal to identify and quantify energy saving opportunities - not final design
• Work together
• Confidentiality
Preparation: Data Request
• Balance value of data versus client time and perceptions
• Typical pre-assessment data:
– Two years of billing data
– Production/sales/occupancy data – Major energy-using equipment and control systems
– Facility layout/plan
Preparation
• Summarize rate schedule and disaggregate costs
• Calculate avoided cost
• Verify billing amounts
• Graph and analyze trends and relationships
• Identify potential savings opportunities
• Define roles within assessment team
Site Visit
1) Briefing and billing analysis
2) Facility walk-through
3) On-site data collection
4) Debriefing
Initial Briefing: Teamwork
• Include upper management
• Two stories to promote teamwork – Client’s advantage: you know this facility– Auditor’s advantage: seen lots of facilities
– Auditor’s job: identify and quantify savings opportunities
– Client’s job: determine if ideas work within multiple constraints
• Most productive if work together
Initial Briefing: Utility Analysis
Structure• Explain rate structure as it relates to client
• Show client how to use rate structure to their advantage
• Show client how to use billing analysis to understand their processes and facilities
Purpose• Develop credibility
• Lead client into discussion of processes and facilities
Explain Rate Structure As It Relates to Client
Service: $95 /month
Energy: $0.00824 /kWh (base)$0.012 /kWh (approximate fuel adjustment)$0.00013 /kWh (PIP)$0.0204 /kWh
Demand: $13.86 /kW-monthGreatest energy use during any 30 minute periodGreatest of:
100% of on-peak (weekdays: 8 am to 8 pm)75% of off-peak (all other times)75% of max in last 11 months
Power Factor: $0.30 /kVAr-month PF charge = {$0.3 x Tan[ArcCos(PF)]} / kW saved
Disaggregate Costs
• Demand/Energy = 50/50– Typical
• Demand/Energy = 60/40– One shift operation– High demand cost
• Demand/Energy = 40/60– Three shift operation– High energy cost
Energy33.4%
Demand65.2%
Service0.4%
Power Factor1.0%
Determine Cost of Avoided Energy
• Avoided cost electricity– Energy: $0.023 /kWh– Demand: $11.23 /kW– Average: $0.071 /kWh
• Avoided cost of natural gas– Winter: $10.43 /mmBtu– Summer: $8.43 /mmBtu– Annual: $9.33 /mmBtu
Verify Billing Amounts
Date DaysConsumption (kWh/period)
Avg Daily Consumption
(kWh/day)
Actual Demand
(kW)
Power Factor
Load Factor
Billed Amount
($/period)
Unit Cost ($/kWh)
Calculated Amount
($/period)11/20/01 32 1,743,914 54,497 6,731 93% 0.34 $110,757 $0.064 $110,75812/20/01 30 1,526,951 50,898 6,610 93% 0.32 $103,913 $0.068 $103,9141/21/02 32 1,404,734 43,898 6,699 93% 0.27 $102,091 $0.073 $102,0932/20/02 30 1,515,385 50,513 4,131 88% 0.51 $95,426 $0.063 $95,4273/20/02 28 1,325,472 47,338 3,945 87% 0.50 $90,469 $0.068 $90,4704/19/02 30 1,334,098 44,470 3,734 88% 0.50 $90,694 $0.068 $90,6955/20/02 31 1,241,993 40,064 3,548 87% 0.47 $88,291 $0.071 $88,2936/20/02 31 1,335,909 43,094 3,758 86% 0.48 $90,741 $0.068 $90,7427/19/02 29 1,197,403 41,290 3,596 85% 0.48 $87,128 $0.073 $87,1308/20/02 32 1,357,669 42,427 3,467 88% 0.51 $84,359 $0.062 $84,3619/20/02 31 1,248,546 40,276 3,256 86% 0.52 $81,513 $0.065 $81,51410/21/02 31 1,260,806 40,671 3,321 86% 0.51 $81,833 $0.065 $81,834
Tot/Avg 367 16,492,880 44,953 4,400 88% 0.43 $1,107,214 $0.067 $1,107,215
Billing Analysis: Every Picture Tells a Story…
Tell Demand and Energy Story
0
20,000
40,000
60,000
80,000
100,000
120,000
1/31
/02
2/28
/02
3/31
/02
4/30
/02
5/31
/02
6/30
/02
7/31
/02
8/31
/02
9/30
/02
10/3
1/02
11/3
0/02
12/3
1/02
Co
ns
um
pti
on
(k
Wh
/da
y)
05001,0001,5002,0002,5003,0003,5004,0004,5005,000
De
am
an
d (
kV
A)
Demand (kW) Consumption (kWh /day)
Quick Electrical Demand Breakdown
• Draw line through winter demand• Below line is “production”, above is “air conditioning”• Ex: Summer = 4,700 kW, Winter = 3,900 kW AC = 800 kW• SEER 10 = 1.2 kW/ton; 800 kW = 670 tons AC
0
20,000
40,000
60,000
80,000
100,000
120,000
1/31
/02
2/28
/02
3/31
/02
4/30
/02
5/31
/02
6/30
/02
7/31
/02
8/31
/02
9/30
/02
10/3
1/02
11/3
0/02
12/3
1/02
Co
ns
um
pti
on
(k
Wh
/da
y)
05001,0001,5002,0002,5003,0003,5004,0004,5005,000
De
am
an
d (
kV
A)
Demand (kW) Consumption (kWh /day)
Quick Electricity Use Breakdown
• Draw line through winter energy use• Below line is “production”, above is “air conditioning”• Ex: Winter = 78,000 kWh/day Average = 83,000 kWh/day• Frac Prod = 78,000 / 83,000 = 94% Frac AC = 6%
0
20,000
40,000
60,000
80,000
100,000
120,000
1/31
/02
2/28
/02
3/31
/02
4/30
/02
5/31
/02
6/30
/02
7/31
/02
8/31
/02
9/30
/02
10/3
1/02
11/3
0/02
12/3
1/02
Co
nsu
mp
tio
n (
kW
h/d
ay
)
05001,0001,5002,0002,5003,0003,5004,0004,5005,000
De
am
an
d (
kV
A)
Demand (kW) Consumption (kWh /day)
Quick Natural Gas Use Breakdown
0
100
200
300
400
500
600
700
1/31
/02
2/28
/02
3/31
/02
4/30
/02
5/31
/02
6/30
/02
7/31
/02
8/31
/02
9/30
/02
10/3
1/02
11/3
0/02
12/3
1/02
Co
ns
um
pti
on
(M
cf/
da
y)
• Draw line through summer energy use• Below line is “production”, above is “space heating”• Ex: Summer = 310 Mcf/dy Average = 430 Mcf/dy• Frac Prod = 310 / 430 = 72% Frac Space Heat = 28%
Energy Breakdowns By Equipment
Equipment Rated Power Frac Loaded Oper Hours Elec Use(hr/yr) (kWh/yr)
AC #1 50 hp 90% 5,000 187,500Lights 10 kW 100% 6,000 60,000… … … … …Other 10,000
Utility Bill Total = 257,500
Equipment Rated Input Frac Loaded Oper Hours Gas Use(Btu/hr) (hr/yr) (MBtu/yr)
Boiler 1 1,000,000 70% 5,000 3,500Make Up #1 500,000 100% 2,000 1,000… … … … …Other 500
Utility Bill Total = 5,000
Gas Fired Make-up Air Unit
10%
Error due to change in outdoor
temp.4%
Parts Washer9%
Paint Dryer9%
Space Heaters (supplied by
boilers)59%
Powder Washer9%
CompTech/Shaffer
21%
CompAir Machining Equipment
13%
Dynos8%
Compressors10%
Lighting27%Fans
4%
Air Conditioning
1%
Other16%
Use Energy Breakdowns To…
• Target areas for investigation
– Savings potential is related to load/use
• Screen savings opportunities
– Estimate annual savings
– Imp cost = simple payback x savings
Graph Energy vs Temperature
R2 = 0.92 CV-RMSE = 7.5%
Graph Energy vs Production
R2 = 0.32 CV-RMSE = 9.2%
Use Graphs To Identify:Departure From Expected Shape
R2 = 0.70 CV-RMSE = 7.8%
Economizer malfunctioning!
Use Graphs to Identify:Non-Production Related Energy Use
R2 = 0.01 CV-RMSE = 22.5%
Equipment Left On!
Use Graphs to Identify:Control Opportunities
R2 = 0.59 CV-RMSE = 67.6%
ObservationHeating Energy Varies by 3X at Same Temp!DiscoveryDidn’t close shipping doors!
Or to Identify Well Controlled Facility…
R2 = 0.99 CV-RMSE = 1.1%
Other Savings Opportunities
• Primary/secondary service– Secondary < 1,000 kVA < Primary
• Power factor correction– Capacitors cost about $30 /kVAR
• Demand reduction potential– Demand potential if 2+ shifts per day
with unbalanced demand
Facility Walk Through
• Generate list of possible savings opportunities– See everything but focus on energy– Safety – Stay on task
• Consolidate ideas and plan next steps– Prioritize savings opportunities– Pursue all opportunities you believe in– Write equations for quantifying savings to
guide data collection effort
On-site Data Collection
• Safety
• Make measurements and observations to quantify opportunities
• Photographs
• Talk to as many levels of personnel as possible
Debriefing
• Include upper management
• Describe savings opportunities
• Answer questions
• Sell ideas and education throughout site visit
Analysis and Reporting
• Purposes and Format
• Documentation
• Delivery
Final Report: Purposes and Format
• Purposes – Document current energy using practices– Identify and quantify saving opportunities
• Format - should support purposes1) Executive summary2) Savings summary table3) Current energy use practices4) Savings calculations5) Implementation
Final Report: Savings Opportunities
• Energy savings opportunities
– Calculate savings (most important)
– Implementation cost (ask for client’s help)
• Consider how to handle synergistic effects
Final Report: Writing Style
• Use first person to identify what you did
• Write completely and concisely– Every number and calculation documented– No word removed without losing information
• Test– Client able to read, understand, agree/disagree,
and modify
Final Report: Delivery
• How?– Deliver report and ask for feedback– Present report– Revise report– Final report
• When? – As soon as possible– Helps client– Reduces errors and omissions
Follow-up
• Initial phone call to answer questions
• Implementation results – Determine which recommendations
implemented– Assess overall satisfaction with service
• Savings measurement and continued support
Summary
• Preparation: sets stage for everything that follows– Set expectations– Credibility– Build on your strengths: rate structures and billing analysis
• Site visit– Create “team” philosophy– Manage time effectively so you “bring home the bacon”– Communicate and sell ideas throughout assessment
• Analysis and reporting– Broad and thorough
• Follow up– Learn from feedback
Site Visit
• Initial briefing– Include upper management– Agree on agenda and deliverables– Roles:
• Your advantage: you know this facility• My advantage: seen lots of facilities• Most productive if work together
• My role is identify and quantify possible savings opportunities• Their role is determine if it can work within multiple constraints, much more difficult
– Discuss utility analysis• Facility walk-through
– Generate list of possible savings opportunities– Safety– Stay on task
• Break– Identify all savings opportunities– Prioritize savings opportunities– Write equations for quantifying savings to guide data collection effort
• On-site data collection– Make measurements and observations to quantify opportunities– Talk to as many levels of personnel as possible
• Debriefing with upper management– Describe savings opportunities– Sell ideas and education throughout site visit
Final Report
• Purposes – Document current energy using practices– Identify and quantify energy saving opportunities
• Format– Executive summary– Savings summary– Energy use practices– Detailed calculations
• Energy savings opportunities– Calculate savings– Estimate implementation cost (ask for help)– Calculate simple payback– Consider synergistic effects
• Write completely and concisely– Completely, every number and calculation documented– Use first person to identify what you did– Should be able to read each analysis and say yes I agree or no because of this.– Concisely, no word could be removed without changing meaning
• Deliver report as soon as possible
Outdoor Air Temperature Data
http://www.engr.udayton.edu/weather