Green Motor RewindsUES Measure Update

Industrial & Agricultural MotorsApril 16, 2013

Reason for bringing back to RTF

• RTF voted to adopt updated measure savings in December, 2012

• Informed that one recommendation from October, 2012 review was not incorporated– The UES assumes NEMA premium efficiency for

the measure motor efficiency, however an average efficiency rating consistent with motors processed through the program should be determined and used instead.

• RTF voted to review data on efficiency weights

Savings Estimation Equation

Where:• UES - Unit Energy Savings is the annual energy savings of the motor in kWh by retaining original

efficiency utilizing rewind process control• HP - Horsepower obtained from standardized horsepower ratings• 0.746 – Converts horsepower to kilowatts• OP - Operating hours is the annual operating hours of the motor• ML - Motor loading is the percentage of the standardized horsepower rating required to drive

equipment• Baseline Eff. – Nameplate motor nominal efficiency without process control (i.e.

range of 0.5% - 1% less than Efficient Case)• Efficient Case Eff. – Nameplate motor nominal efficiency with process control

HP x 0.746 x OP x ML HP x 0.746 x OP x MLUnit Energy Savings (kWh/yr) Baseline Eff. Efficient Case Eff.

=

Changes made to Workbook

• Open Workbook– Clarified analysis method on Summary Tab– Corrected source documentation for efficient case– Incorporated GMPG data tables for efficiency

values at each HP– Added references to for Pre-EPAct, EPAct and

NEMA Premium efficiency tables– Removed analysis for motor sizes <15 HP as GMPG

does not offer these

Methodology

• Current Methodology:– Use NEMA Premium as the Efficient Case motor

efficiency• (i.e. all motors entering GMPG are NEMA premium

efficiency)– Conservative estimate from initial measure

development in 2007• Proposed Methodology:– Develop estimate of Efficient Case motor efficiency

weightings for each HP size based on count of motors entering program

Proposed Method Data Sources• GMPG efficiency data collected from historical program

participation by motor size – N=2337 motors from program years 2008-2012

• Pre-EPAct motor efficiency– MotorMaster database – Conversation with Gil McCoy at WSU indicated efficiencies for

pre-1989 motors were based on ~10,000 motors available at that time

– Un-stamped nameplate indicates a Pre-EPAct motor• EPAct and NEMA Premium motor efficiency– Published efficiency tables from DOE

Weightings table*Table 3: Efficiency Levels For 15HP to 500 HP Processed Through GMI by Horsepower

HPPre-EPact Motors EPact NEMA Premium® Total

N = % of Total N = % of Total N = % of Total N =

15 82 50% 25 15% 57 35% 164

20 115 69% 32 19% 19 11% 166

25 75 72% 21 20% 8 8% 104

30 77 76% 14 14% 10 10% 101

40 88 73% 20 17% 13 11% 121

50 71 69% 17 17% 15 15% 103

60 61 82% 10 14% 3 4% 74

75 191 82% 30 13% 13 6% 234

100 127 76% 21 13% 19 11% 167

125 85 75% 15 13% 13 12% 113

150 141 81% 28 16% 6 3% 175

200 230 81% 44 15% 10 4% 284

250 123 93%     9 7% 132

300 127 94%     8 6% 135

350 75 91%     7 9% 82

400 106 96%     4 4% 110

450 31 94%     2 6% 33

500 39 100%     0 0% 39

Total 1844  79% 277 12%  216  9% 2337

*Represents number of motors collected during program years Sept. 2008 – Aug.2012

Decision needed

• SBW recommended that an average efficiency rating consistent with motors processed through the program should be determined and used instead.

• Question: Is the weighting methodology and GMPG program data sufficiently reliable to use for this estimate?

Revised Savings15 20 25 30 40 50 60 75 10

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Industrial Savings ChangePrevious Savings 12-11-12 Proposed Savings 04-16-13

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Revised Savings15 20 25 30 40 50 60 75 10

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Agricultural Savings ChangePrevious Savings 12-11-12 Proposed Savings 04-16-13

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RTF Proposed Motion:

I ______________ move that the RTF incorporates the motor efficiency data and sources presented , updates the UES savings values for both Industrial and Agricultural Green Motor Rewinds, and moves the measures from “Under Review” to “Active” status.

BACK-UP SLIDESReference Only - December 2012 RTF Presentation

Green Motor Rewinds

Measure Classification and PropertiesMarket Sector Industrial; AgriculturalMarket Segment All SegmentsMeasure Category Motors

Measure DescriptionMotors are rewound by Green Motors Practices Group (GMPG) program participants to the GMPG specifications rather than non-participant motor rewind shops. Measures are identified by motor horsepower ratings that range from 7.5 to 5,000.

Sunset Criteria October 1, 2017

Primary Workbook ProCostRTFTemplate257f_v3_9 Green Motor Rewinds 12_3_12 v11.xlsm

Linked Workbooks None

Number of Measures, and UES Components

72 total measures each calculated using a single UES component: 36 horsepower ratings x 2 market sectors (ind and ag)

Green Motor Rewinds

Summary of Actions to DateTask Task Source Result

Update efficiency rating assumption for motors greater than 500 horsepower.

Recommendation memo

Resolved. Manufacturer data for motors 600 HP and above provided by GMPG submittal.

Consider developing additional measure categories by motor type [Totally Enclosed Fan Cooled (TEFC), Open Drip Proof (ODP)] or motor speed (1200-3600 rpm).

Recommendation memo

Discussion item. Navigant recommends no further categorization as this provides little effect (~1-2%) on overall savings.

Update standard rewind efficiency degradation assumption with studies of significantly smaller and larger motors.

Recommendation memo

Discussion item. A study of smaller motor (7.5 HP) rewind efficiency degradation was provided by GMPG submittal.

Studies of motors larger than 150 HP are unavailable, as are studies of rewind efficiency degradation comparing motors in the field.

Update duty cycle (operating hours) using average op hours, by horsepower rating, from the NW Motor Database.

Recommendation memo

Industrial op hours – Discussion item. Cascade Energy found that NW database run hours show minimal correlation to motor size and end use.1

Agricultural op hours – Resolved. BPA provided motor operating hour data from its Ag Irrigation program.

1 Cascade Energy, presentation to the RTF on super high efficiency motors. November 14, 2012.

Green Motor Rewinds

Summary of Actions to Date (Continued)Task Task Source Result

Update motor load factor assumption using average load factor, by horsepower rating, from the NW Motor Database.

Recommendation memo

Agricultural motor loading – Resolved. Based on BPA data compiled between 2002 and 2012 of actual motor loads measured during irrigation pump testing.

Industrial motor loading – Discussion item. See Discussion item 2) below.

Combine industrial and agricultural green motor rewind RTF workbooks due to major similarities between them.

NWPCC / Navigant

Resolved. Navigant combined industrial and agricultural efficient motor rewinds into a single workbook.

Conduct further research into: 1) efficiency degradation assumption used by MotorMaster software, and 2) load factor assumptions in the NW Motor Database

November RTF Meeting

Discussion items:1) According to DOE, the MotorMaster standard

efficiency degradation assumption of 0.5 to 1% is based primarily on an EASA study of six 100-150 HP motors.

2) Motor loading data in the NW motors database was collected in a number of ways (metered/calculated, self-reported, estimated, etc.). Reported motor load estimates do not account for idle time.

Discussion Item: Additional Measure Categories

Green Motor Rewinds

HP Average annual

Energy Savings for GMPG Rewind (kWh)Min

Savings (kWh)

Max Savings(kWh)

Average Savings (kWh)

% Difference, Avg Savings vs. Max

SavingsODP TEFC

1200 RPM 1800 RPM 3600 RPM 1200 RPM 1800 RPM 3600 RPM7.5141 139 147 139 137 144 137 147 141 4.10%10182 182 192 185 182 189 182 192 186 3.30%20359 355 371 365 355 371 355 371 363 2.20%25532 525 547 532 525 547 525 547 535 2.30%50725 719 742 725 719 742 719 742 729 1.90%751,007 996 1,026 1,007 988 1,026 988 1,026 1,009 1.80%

1001,550 1,537 1,597 1,550 1,537 1,580 1,537 1,597 1,558 2.50%1251,890 1,875 1,927 1,890 1,875 1,890 1,875 1,927 1,891 1.90%1502,250 2,231 2,312 2,231 2,231 2,269 2,231 2,312 2,254 2.60%2002,999 2,974 3,025 2,974 2,950 2,999 2,950 3,025 2,987 1.30%2504,421 4,384 4,459 4,384 4,348 4,384 4,348 4,459 4,397 1.40%3005,305 5,261 5,305 5,261 5,217 5,261 5,217 5,305 5,269 0.70%4007,015 7,015 7,015 7,015 6,956 7,015 6,956 7,015 7,005 0.10%5008,695 8,695 8,768 8,768 8,695 8,768 8,695 8,768 8,732 0.40%

Navigant does not recommend extending motor rewind categories to differentiate between motor type (ODP/TEFC) or motor speed (1200-3600 RPM), as these have a minimal effect on overall savings. (Note: This would also add an additional 360 measure line items).

HP Range Load Factor Annual Op. Hours5 to 20 HP 79% 5,325

25 to 50 HP 80% 5,59260 to 100 HP 78% 5,829125 to 200 HP 80% 5,922250 to 500 HP 82% 5,743

600 to 1,000 HP 82% 7,0651,025 to 5,000 HP 82% 7,038

Discussion Item: Industrial Motor Loading and Op Hours

Green Motor Rewinds

• NW Industrial Motor Database load factors were collected through different methods including metering/calculating, self-reported, and estimated based on end use. Reported motor load estimates do not account for idle time.

• Cascade Energy RTF presentation found minimal correlation between size, op hours and end use in the NW Industrial Motors Database.1 Table below shows current industrial motor estimates.

1 Cascade Energy, presentation to the RTF on super high efficiency motors. November 14, 2012.

• MotorMaster’s default standard rewind efficiency degradation (0.5 – 1%) is primarily based on 2003 EASA lab test of six motors between 100 and 150 HP.1

• Lab test showed efficiency degradation from non-process controlled rewinds of 0.3 to 1% (with an average of 0.6%).

• The 2003 EASA study, in conjunction with the MotorMaster default assumption (which is also based on EASA) was previously used as the RTF’s standard efficiency rewind degradation assumption.

• GMPG submittal provided a second study by the Association of Electrical and Mechanical Trades (AEMT) of much smaller motors (7.5 HP) showing efficiency degradations between 0.5 and 3%. 2

• Studies of efficiency degradation for motors larger than 150 HP are unavailable.

• Studies of efficiency degradation comparing motors in the field or program/non-program participants are also unavailable.

Discussion Item: Standard Rewind Efficiency Degradation

Green Motor Rewinds

1 EASA/AEMT (2003). The Effect of Repair and Rewinding on Motor Efficiency. 2 AEMT (1996). The AEMT Good Practices Guide – Appendix 2: Burn-out Ovens and Their Effect on Stator Core Losses.

Do the Studies Used for Standard Rewind Efficiency Degradation Meet One of the Allowable Proven UES Estimation Procedures?

Green Motor Rewinds

• Procedure 1: Statistical (Section 3.1.1, pg. 8 of the guidelines)

• “The UES estimate may be derived from statistical analysis of baseline and efficient case energy use.”*

• Navigant’s recommendation: Does not meet guidelines

• Neither the 2003 EASA study nor the 1996 AEMT study were designed to provide statistical samples of a population.

• To use either of these studies as the statistical sample of the NW motor rewind population is not statistically justifiable.

• Procedure 2: Meta-Statistical (Section 3.1.2, pg. 9 of the guidelines)

• “In some cases, relatively small statistical studies are conducted by a number of different agencies. None of these studies alone provide sufficient confidence in the UES estimate. However, the RTF may determine that a value in the range of savings demonstrated by these studies constitutes a sufficiently reliable estimate.”*

* Regional Technical Forum (RTF). Guidelines for the Development and Maintenance of RTF Savings Estimation Methods. June 1, 2011.

Green Motor Rewinds

• Navigant’s recommendation: RTF needs to decide if these studies qualify as meta-statistical per the guidelines

• The provided motor rewind studies are not “statistical studies” in the sense that the motors tested were not designed be a statistical sample of a population.

• If the studies are considered to be “statistical studies,” the RTF could determine a “sufficiently reliable estimate” from these studies – which in the case of standard motor efficiency degradation would be some value between 0.3 and 3% (with an average closer to 0.6%).

• Procedure 3: Calibrated Engineering (Section 3.1.3, pg. 9 of the guidelines)

• “UES may be estimated with calibrated engineering procedures… Calibrated engineering estimates may be based on measurement and modeling of savings for randomly selected end users. Alternatively, they may be any group of program participants, if the RTF determines that the group is sufficiently representative of likely future participants.”*

* Regional Technical Forum (RTF). Guidelines for the Development and Maintenance of RTF Savings Estimation Methods. June 1, 2011.

Do the Studies Used for Standard Rewind Efficiency Degradation Meet One of the Allowable Proven UES Estimation Procedures?

Green Motor Rewinds

• Navigant’s recommendation: RTF needs to decide if this study qualifies as a calibrated engineering study per guidelines

• It does not appear that the provided studies use “randomly selected end users” or “program participants” for the motors tested.

• The GMPG submittal references The Canadian Standards Association (CSA) Standard C392-111, which may be able to assess savings of this measure going forward, in conjunction with additional data; however, collecting the data would be difficult.

• C392-11’s foreword states, “This Standard provides guidance to electric motor service centers in verifying that the refurbishing process has maintained or enhanced the electric motor (hereafter motor) efficiency. It is also intended to provide a reliable evaluation of changes in the condition of the motor, with respect to its efficiency that might have resulted from its failure…”

1 Canadian Standards Association (CSA). Standard C392-11, Testing of three-phase squirrel cage induction motors during refurbishment. 2011.

Do the Studies Used for Standard Rewind Efficiency Degradation Meet One of the Allowable Proven UES Estimation Procedures?

Energy Savings Results Comparison – Industrial Sector

Green Motor Rewinds

HP Prior to Update

(kWh/yr)

Current Update

(kWh/yr) HP

Prior to Update

(kWh/yr)

Current Update

(kWh/yr) 7.5 141 292 450 7,859 8,622

10 186 384 500 8,732 9,580 15 274 567 600 12,279 14,689

20 363 750 700 14,326 17,065 25 535 980 800 16,372 19,461

30 575 1,053 900 18,419 21,847 40 672 1,232 1,000 21,177 24,080

50 729 1,336 1,250 26,472 29,973 60 971 1,380 1,500 31,766 35,891

75 1,009 1,434 1,750 37,060 41,697 100 1,558 1,899 2,000 42,355 47,454

125 1,891 2,462 2,250 47,649 53,051 150 2,254 2,933 2,500 52,943 58,823

200 2,987 3,888 3,000 63,532 70,147

250 4,397 4,824 3,500 74,121 81,667 300 5,269 5,780 4,000 84,709 93,334

350 6,147 6,744 4,500 95,298 104,783 400 7,005 7,685 5,000 105,887 116,183

Energy Savings Results Comparison – Industrial Sector

Green Motor Rewinds

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TRC Comparison – Industrial Sector

Green Motor Rewinds

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Energy Savings Results Comparison – Agricultural Sector

Green Motor Rewinds

HP Prior to Update

(kWh/yr)

Current Update

(kWh/yr) HP

Prior to Update

(kWh/yr)

Current Update

(kWh/yr) 7.5 75 154 450 2,563 4,896

10 98 203 500 2,848 5,440 15 145 299 600 3,418 6,193

20 192 396 700 3,987 7,195 25 237 554 800 4,557 8,205

30 254 596 900 5,126 9,211 40 297 696 1,000 5,696 10,192

50 322 755 1,250 7,120 10,590 60 328 715 1,500 8,544 12,681

75 341 743 1,750 9,968 14,732 100 585 985 2,000 11,392 16,766

125 727 1,096 2,250 12,816 18,744 150 867 1,306 2,500 14,240 20,783

200 1,149 1,731 3,000 17,088 24,784 250 1,434 2,739 3,500 19,936 28,854

300 1,718 3,282 4,000 22,784 32,976 350 2,005 3,829 4,500 25,632 37,021

400 2,285 4,364 5,000 28,479 41,049

Energy Savings Results Comparison – Agricultural Sector

Green Motor Rewinds

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TRC Comparison – Agricultural Sector

Green Motor Rewinds

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