METHODS FOR ESTIMATING NET SAVINGS FOR 2004-2005 STATEWIDE RARP

1
METHODS FOR ESTIMATING NET SAVINGS FOR 2004-2005
STATEWIDE RARP

• Presentation at CALMAC Meeting
• Pacific Energy Center
• July 18, 2007

Presentation by Donald DohrmannADM Associates,
Inc.
2
Presentation Overview

• Historical Context of RARP Net Savings Estimation
• KEMA Method for Estimating Net Savings for 2002
  RARP
• KEMA Method Applied to 2004-2005 RARP
• Modifications to KEMA Method
• Method for Estimating Free-ridership

3
Estimating Net Savings for RARPObjectives

• Determine program-level savings attributable to
  RARP
• (i.e., What proportion of gross savings
  resulted because of program?)

4
Previous NTG Estimates
Impact Evaluation of 1994 Spare Refrigerator Recycling Program, Project ID 515, Final Report to SCE, Xenergy, 1996 0.42
Impact Evaluation of the Spare Refrigerator Recycling Program, CEC Study 537, Final Report to SCE, Xenergy, 1998 0.53
Measurement and Evaluation Study of 2002 Statewide Residential Appliance Recycling Program, Final Report, KEMA-Xenergy, 2004 0.35
Measurement and Verification Report for NCPA SB5X Refrigerator Recycling, Final Report, Robert Mowris Associates, 2003 0.64
Measurement and Verification of SB5X Energy Efficiency Programs for the Sacramento Municipal Utility District, Final Report, Heschong Mahone Group, 2003 0.55
5
Estimating Net SavingsIssues

• Overall drop in NTG 1996-2002 programs .53 to
  .35.
• Rise in proportion who would have discarded
  without program.41 to .86
• Drop in proportion who would have continued use
  without program .45 to .09
• Disaggregated NTG (2003)
• Among primary refrigerators .37
• Among secondaries .65
• Among freezers .73

6
Estimating Net SavingsGuiding Principles

• Maintain consistency with past evaluations of
  RARP (as much as possible)
• Improve statistical precision of estimates

7
Estimating Net SavingsHow NTG Estimated-2002
Program
8
Estimating Net SavingsHow NTG Estimated-2002
Program
9
2002 NTG Re-stated
What Would Have Happened to Recycled Unit Percentage of Refrigerators in Category Attribution Factor Part Use Factor P x A x U
Kept but not used 4.60 1.000 0.000 0.000
Kept in use 9.00 1.000 0.880 0.079
Discarded-Destroyed 21.43 0.000 0.000 0.000
Discarded-Transferred 64.97 0.429 0.977 0.272
Overall NTG 0.351
10
2004-2005 Per KEMA Method
What Would Have Happened to Recycled Unit Percentage of Refrigerators in Category Attribution Factor Part Use Factor P x A x U
Kept but not used 4.1 1.000 0.000 0.000
Kept in use 12.0 1.000 0.923 0.111
Discarded-Destroyed 25.8 0.000 0.000 0.000
Discarded-Transferred 58.1 0.520 0.988 0.298
Overall NTG 0.409
11
Discarded-Transferred Calculation2002
Main or Spare Unit What Would Transferree Do Because Unit Not Available Percentage of Refrigerators in Category Attribution Factor P x A
Main Buy new unit 33.8 0.70 0.236
Main Buy/fix similar unit 35.1 0.00 0.000
Main Buy worse unit 5.2 0.00 0.000
Main Not buy another 6.5 1.00 0.065
Spare Buy new unit 5.2 0.70 0.036
Spare Buy/fix similar unit 3.9 0.00 0.000
Spare Buy worse unit 1.3 0.00 0.000
Spare Not buy another 9.1 1.00 0.091
Result 0.429
12
Discarded-Transferred Calculation2004-2005
Main or Spare Unit What Would Transferree Do Because Unit Not Available Percentage of Refrigerators in Category Attribution Factor P x A
Main Buy new unit 44.4 0.70 0.311
Main Buy/fix similar unit 21.4 0.00 0.000
Main Buy worse unit 3.8 0.00 0.000
Main Not buy another 14.1 1.00 0.141
Spare Buy new unit 3.7 0.70 0.026
Spare Buy/fix similar unit 7.5 0.00 0.000
Spare Buy worse unit 0.8 0.00 0.000
Spare Not buy another 4.2 1.00 0.042
Result 0.520
13
Discarded-Transferred CalculationBuying of Used
Unit
Energy Use Before Energy Use After Savings
Unit recycled and not transferred E 0 E
Unit to be bought ??E ?E (? -1)?E
Totals E(1 ??) ?E E(1 ?? - ?)
? portion of year used unit was on grid using electricity
? energy use of purchased used unit vis-a-vis recycled unit
14
Discarded-Transferred Calculation Example
Alternatives for Used Units
Inventory Turnover ? ? Attribution Factor NTG
0 0 1.0 0.520 0.409
2.2 0.545 1.0 0.677 0.500
3.6 0.722 1.0 0.728 0.529
0 0 0.7 0.606 0.459
2.2 0.545 0.7 0.717 0.522
3.6 0.722 0.7 0.753 0.543
15
Estimating Net of Free-Ridership Impacts

• Per most recent protocols from CPUC
• Two categories for free-ridership
• Unit kept but not used
• Unit discarded in way that it would be destroyed
• Includes some units discarded to dealers

16
Data for Estimating Free-ridership for 2004-2005
RARP

• Customer Telephone Surveys
• 716 households that participated in 2004-05 RARP
• 354 households that did not participate in the
  2004-05 RARP but that disposed of a refrigerator
  in past four years

17
Free-ridership ComponentsPrimary Refrigerators
Kept Not Used
PGE SCE SDGE All
kept 11.0 10.0 10.1 10.2
of kept not used 50.0 38.1 33.3 38.8
kept but not used 5.50 3.82 3.37 3.96
18
Free-ridership ComponentsPrimary Refrigerators
Destroyed
Non-participant survey PGE SCE SDGE All
discarded 89.0 90.0 89.9 89.8
of discarded destroyed 47.8 39.8 45.4 43.6
destroyed 42.5 35.8 40.8 39.1
Participant survey PGE SCE SDGE All
discarded 89.0 90.0 89.9 89.8
of discarded destroyed 58.0 36.1 51.7 41.7
destroyed 51.6 32.5 46.5 37.5
19
Free-ridership Estimates2004-2005 RARP Primary
Refrigerators
PGE SCE SDGE All
FREE-RIDERSHIP FREE-RIDERSHIP FREE-RIDERSHIP FREE-RIDERSHIP FREE-RIDERSHIP
Non-participant survey 48.0 39.6 44.2 43.1
Participant survey 57.1 36.3 49.9 41.4
NET OF FREE-RIDERSHIP NET OF FREE-RIDERSHIP NET OF FREE-RIDERSHIP NET OF FREE-RIDERSHIP NET OF FREE-RIDERSHIP
Non-participant survey 52.0 60.4 55.8 56.9
Participant survey 42.9 63.7 50.1 58.6
20
Statistical Precision

• Standard errors for proportions
• Propagation of error techniques
• Sample sizes major factor
• 2004-2005 sample sizes gt 2002 sample sizes
• 2004-2005 participant sample size gt 2004-2005
  non-participant sample sizes
• Sample sizes smaller for individual utility
  estimates
• Samples for refrigerators gt samples for freezers

21
Comparison of Sample SizesRefrigerators
2002 2004-2005
Keep/Discard 390 716
Destroy/Transfer 138 354
Acquisition 77 210