Effective Energy Management Effective Energy Management Develop baseline
Effective Energy Management
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
Energy Use Baseline – Plant energy balance • Map energy use throughout the plant – Statistical analysis (Lean Energy Analysis) • Understand drivers of energy use
Estimate Equipment Electricity and Fuel Use 1) Estimate energy use from: • rated power • frac loaded • operating hours 2) Calibrate sum against measured total energy use
Electricity And Fuel Energy Balances
Map Energy From Supply to Conversion To Process
Plant Energy Balances § Use plant energy balances to: – Identify biggest energy users – Prioritize action plans – Calibrate savings estimates
Lean Energy Analysis
Statistical ‘Lean Energy Analysis’ § Quantifying relationship between: – Energy – Production – Weather by developing simple statistical models § Deriving actionable information from models
Source Data
Actual Temperature Data http: //www. engr. udayton. edu/weather
Time Trends: Electricity and Outdoor Temperature
Time Trends: Electricity and Production
Electricity vs Toa: 3 PC R 2 = 0. 67 CV-RMSE = 6. 4%
Electricity vs Production: 2 P R 2 = 0. 32 CV-RMSE = 9. 2%
Electricity vs Toa: 3 PC-MVR R 2 = 0. 82 CV-RMSE = 5. 1%
Elec = Ind + Wea-dep + Prod-dep E (k. Wh/dy) = 41, 589 (k. Wh/dy) + 361. 159 (k. Wh/dy-F) x [Toa (F) – 30. 7093 (F)]+ + 2. 4665 (k. Wh/dy-unit) x P (units) Independent = 41, 589 (k. Wh/dy) Wea-dep = 361. 16 (k. Wh/dy-F) x [Toa (F) – 30. 71 (F)]+ Prod-dep = 2. 4665 (k. Wh/dy-unit) x P (units)
Disaggregate Electricity Use Electricity Weather = 10% Production = 39% Independent = 51% Temperature
Time Trends: Fuel Use and Outdoor Temperature
Time Trends: Fuel Use and Production
Fuel Use vs Toa: 3 PH R 2 = 0. 92 CV-RMSE = 7. 5%
Fuel Use vs Toa: 3 PH-MVR R 2 = 0. 97 CV-RMSE = 5. 1%
Fuel Use = Ind + Wea-dep + Proddep Fuel Use (mcf/dy) = 59. 58 (mcf/dy) + 9. 372 (mcf/dy-F) x [62. 06 (F) - Toa (F)]+ + 0. 0199 (mcf/dy-unit) x P (units) Independent = 59. 58 (mcf/dy) Wea-dep = 9. 372 (mcf/dy-F) x [62. 06 (F) - Toa (F)]+ Prod-dep = 0. 0199 (mcf/dy-unit) x P (units)
Disaggregate Fuel Use Fuel Weather = 28% Production = 58% Independent = 14% Temperature
‘Lean Energy Analysis’ § Called “lean energy” analysis because of its synergy with the principles of “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 Electricity Use Electricity Weather = 10% Production = 39% “Independent” is energy not added to product. Perfectly “lean” when Ind = 0 Independent = 51% Temperature
Quantified “Leaness” of Fuel Use Fuel Weather = 28% Production = 58% “Independent” is energy not added to product. Perfectly “lean” when Ind = 0 Independent = 14% Temperature
How ‘Lean’ is Your Electricity Use?
How ‘Lean’ is Your Fuel Use?
Using ‘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
Large Independent Fuel Use Identifies Insulation Opportunities • 50% of fuel use by holding furnaces • Insulate furnaces and switch to coreless furnaces
Departure From Expected Shape Identifies Malfunctioning Economizers § Air conditioning electricity use should flatten below 50 F § Audit found malfunctioning economizers
High Data Scatter Identifies Control Opportunities • Observation: heating energy varies by 3 x at same temp • Discovery: didn’t close shipping doors
High Heating Slope Identifies Excess Ventilation • Turn off excess exhaust air fans reduces vent by 13, 000 cfm • Lowers heating slope, balance temperature, and fuel use
Lean Energy Analysis § Quick, accurate disaggregation of energy use: – Quantifies non-value added energy – Helps identify savings opportunities – Provides an accurate baseline for measuring the effectiveness of energy management efforts over time.
Take Action § Identify and quantify saving opportunities § Prioritize saving opportunities § Implement saving opportunities
Identify and Quantify Saving Opportunities § Identifying energy saving opportunities – Use “Integrated Systems + Principles Approach (ISPA) § Quantifying energy savings: may consider – Equipment vendors (compressed air, boiler, etc. ) – Energy savings performance contractor (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 § Maintenance commitment § Operator commitment
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 – Use LEA model to measure savings § Benchmarking – Use LEA model to compare facilities
Measure Weather-Normalized and Production-Normalized Energy Savings Pre-retrofit Post-retrofit
Track Weather-Normalized and Production-Normalized Energy Use (NAC) Solid Line: NAC Dashed Line: Actual Consumption Annual Consumption increased 17%. NAC increased 6% Plant energy efficiency decreased 6%.
Track Weather-Normalized and Production-Normalized Energy Intensity (NEI) Normalized Energy Intensity decreased 5. 4%.
Benchmarking § Comparing energy performance across multiple sites § Benchmark best/worst NAC and change in NAC § Benchmark best/worst coefficients and change in coefficients
The Big Picture: Electricity NAC and DNAC for 14 Facilities DNAC
More Detail: Ei and DEi Best candidates for lighting retrofits DEi Ei
More Detail: Tb and DTb DTB Best candidates for controls retrofits TB
More Detail: CS and DCS Best candidates for HVAC retrofits DCS CS
Effective Energy Management: Summary § Develop baseline – Plant energy balance (breakdown) – Lean energy analysis (drivers) § Take action – Identify and quantify energy saving opportunities – Prioritize and implement energy saving opportunities – Implement energy saving opportunities § Measure and benchmark to sustain efforts – Use LEA models to measure energy efficiency improvement – Compare energy efficiency between facilities
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