effective energy management. 1.develop baseline 2.identify and quantify savings opportunities...
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Effective Energy Management
Effective Energy Management
1. Develop baseline
2. Identify and quantify savings opportunities
3. Measure and benchmark to sustain efforts
1. Energy Use Baseline
–Billing analysis• How energy is priced
–Plant energy balance• Where energy is used
– Lean energy analysis (LEA)• What drives changes in energy use
Utility Bill Analysis
Analyze rate schedule Verify billing amounts Check for saving
opportunities:– Primary/secondary– Power factor correction– Meter consolidation– Demand reduction
potential Benchmark costs
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Plant Energy Balance
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
1) Estimate energy use from:
• rated power• frac loaded• operating hours
2) Calibrate sum against measured total energy use
Energy Use Breakdowns by Equipment
0% 12% 24% 36% 48% 60%
Vacuum Pumps
Process Blowers/Fans
Lighting
Dust Collectors
Sanders
Other Process Motors
Air Compressors
Process Heating
Other
20%
18%
17%
12%
12%
8%
6%
5%
2%
Estimated Electrical Use Breakdown
Lean Energy Analysis
Understand what drives changes in Energy
Quantify “Waste” and “Lean”
Model: Energy = a + b Production + c Weather
Source Data
Date Elec (kWh/dy) Nat Gas (mcf/dy) Prod (units/dy) Toa (F)1/31/2002 76,127 590 13,065 34.72/28/2002 80,564 581 13,557 34.73/31/2002 77,362 542 12,401 39.44/30/2002 81,712 418 14,086 53.55/31/2002 80,059 348 14,181 58.66/30/2002 90,094 298 13,439 72.57/31/2002 86,361 287 10,551 77.48/31/2002 89,326 341 14,239 75.89/30/2002 95,441 348 13,830 69.710/31/2002 82,779 434 12,693 51.511/30/2002 77,639 535 12,977 39.612/31/2002 61,288 518 9,982 30.7
Actual Temperature Data
http://academic.udayton.edu/kissock
Plot Fuel vs Toa
Model Fuel Use vs Toa: 3PH
R2 = 0.92
HS
Find
Tcp
Model Fuel Use vs Production: 2P
R2 = 0.02 Prod Slope Negative
Model Fuel Use vs Toa and Prod: 3PH-MVR
R2 = 0.97 Prod Slope = Positive
Disaggregate Fuel Use
Weather = 28%
Production = 58%
Independent = 14%
Temperature
Fuel
Model Electricity vs Toa: 3PC
R2 = 0.67
Model Electricity vs Production: 2P
R2 = 0.32
Model Electricity vs Toa and Prod: 3PC-MVR
R2 = 0.82
Disaggregate Electricity Use
Weather = 10%
Production = 39%
Independent = 51%
Temperature
Electricity
Lean Energy Analysis
Called “Lean Energy Analysis” because of synergy with “Lean Manufacturing”.
In lean manufacturing, “any activity that does not add value to the product is waste”.
Similarly, “any energy that does not add value to a
product or the facility is also waste”.
Quantified “Leaness” of Fuel Use
Weather28%
Production58%
Independent14%
“Independent” is a metric of energy not added to productFuel LEA = %Production + %Weather
Fuel LEA = 86%
Quantified “Leaness” of Electricity Use
Production39%
Independent51%
Weather10%
“Independent” is a metric of energy not added to productElectricity LEA = %Production + %Weather = 49%
Electricity LEA = 49%
Average LEA Scores (%P+%W)(28 Manufacturing Facilities)
39%
58%
Use Lean Energy Analysis To Discover Savings Opportunities
LEA Indicators of Savings Opportunities– High “Independent” indicates waste– Departure from expected shape– High scatter indicates poor control
Low Electric LEA = 24%Indicates Operating Opportunities
Low Fuel LEA Identifies Insulation Opportunities
High Heating Slope Identifies Heating Efficiency / Insulation Opportunities
High Data Scatter Identifies Control Opportunities
Heating Energy Varies by 3X at Same Temp!
Departure From Expected Shape Identifies Malfunctioning Economizers
Air conditioning electricity use should flatten below 50 F Audit found malfunctioning economizers
Lean Energy Analysis
Quick but accurate disaggregation of energy use: – Quantifies the energy not adding value to product or
the facility– Helps identify savings opportunities– Provides an accurate baseline for measuring the
effectiveness of energy management efforts over time.
2. Identify and Quantify Saving Opportunities
Identifying energy savings– Use “Integrated Systems + Principles Approach (ISPA)– ISPA is effective and thorough
Quantifying energy savings– Requires competent engineering– May warrant energy audit– May consider energy savings performance contract (ESPC)
Prioritize Saving Opportunities
Multiple filters– Financial return on investment
• Rank versus other energy saving opportunities• Rank versus other requests for capital• Risk
– Consistent with other priorities– Available and knowledgeable staff to manage project
Implement Savings Opportunities
Management commitment Operator and maintenance education and buy in
3. Measurement and Benchmarking
Sustaining energy efficiency efforts requires that effectiveness of past efforts be accurately evaluated. – Verify the performance of past energy-efficiency efforts– Inform the selection of future energy-efficiency initiatives– Help develop energy-efficiency targets
Measurement – Extend LEA with sliding NAC and EI to measure energy
efficiency improvement Benchmarking
– Compare NAC and EI for inter-facility benchmarking
Normalized Energy Intensity
1) Characterize performance with ‘Energy signature’ model
2) Remove noise with ‘Normalized annual consumption’ NAC
3) Track performance with ‘Sliding NAC’ analysis
4) Benchmark performance with ‘Multi-site sliding NAC’ analysis
Raw Energy and Production Data
Normalized Energy Intensity
Benchmark NEI vs. Multiple Facilities
Smallest Energy Users
Biggest Energy Decrease
Biggest Energy Increase
Biggest Energy Users
DNEI
NEI
Case Study: Turn off Make-up Air Units During Non-Production Hours
Baseline Post-retrofit
Heating Slope Decreases by 50%
Sliding NEI
Fuel NEI decreased by 23%
Independent of weather/production changes
Summary: Effective Energy Management
Develop baseline– Plant energy balance– Lean energy analysis (LEA)
Take action – Identify and quantify energy saving opportunities– Prioritize energy saving opportunities– Implement energy saving opportunities
Measure and benchmark to sustain efforts– Develop metrics for system energy efficiency– Measure energy efficiency improvement with sliding NAC and EI– Compare energy efficiency between facilities with NAC and EI