Report on Electronic Ballast DSM Rebate Research

Lawrence Berkeley National Laboratory

April 10, 1998

Abstract

In May of 1997, LBNL began to collect data for a study of the impact of DemandSide Management (DSM) programs on the market for electronic fluorescent ballasts. This

investigation into the historical trends in DSM rebates for electronic ballasts was

undertaken to inform predictions about the future developments in the fluorescent ballast

market. The most significant finding of this study is the substantial decrease in the number

of DSM rebates for electronic ballasts. It is possible that fewer DSM rebates for

electronic ballasts has contributed to the slowed growth since 1995 in the market share

garnered by electronic ballasts.

Two sample data sets, referred to as the core and expanded samples, were

collected for this study. The core data set includes six utilities. The total energy efficiency

spending of these six utilities represents about 15% to 20% of national spending on energy

efficiency programs, a large component of DSM spending that includes all rebate

programs. The expanded sample data set adds three utilities to the core; some estimation

was required to fill in the less than absolutely complete information these three additional

utilities provided. Total energy efficiency expenditures for utilities in the expanded sample

account for roughly 25% to 35% of national expenditures. It is not known whether or not

the sample is representative of the nation as a whole.

In order to estimate DSM rebates for electronic ballasts, we first calculated the

fraction of energy efficiency spending devoted to electronic ballast rebates and the average

value of the rebate per ballast for the sample data. Next, we assumed that in each year the

average rebate value and fraction of EE spending going to ballast rebates was the same for

the nation as in our sample. For each year, nationally-aggregated energy efficiency

spending was multiplied by the fraction of EE spending going to ballast rebates in our

sample to estimate national spending on ballast rebates. Then, we divided this estimate of

spending on ballast rebates by the average rebate per ballast to estimate the number of

ballasts rebated for the year. The assumptions used in our estimation technique as well as

concerns about the size of our sample data sets and whether or not they are representative

are discussed in the last section of this report which covers uncertainty.

I

EE-RM-97-500 COMMENT 20G

Report on Electronic Ballast DSM Rebate Research 

Lawrence Berkeley National Laboratory 

April 10, 1998 

Abstract 

In May of 1997, LBNL began to collect data for a study of the impact of DemandSide Management (DSM) programs on the market for electronic fluorescent ballasts. This 

investigation into the historical trends in DSM rebates for electronic ballasts was 

undertaken to inform predictions about the future developments in the fluorescent ballast 

market. The most significant finding of this study is the substantial decrease in the number 

of DSM rebates for electronic ballasts. It is possible that fewer DSM rebates for 

electronic ballasts has contributed to the slowed growth since 1995 in the market share 

garnered by electronic ballasts. 

Two sample data sets, referred to as the core and expanded samples, were 

collected for this study. The core data set includes six utilities. The total energy efficiency 

spending of these six utilities represents about 15% to 20% of national spending on energy 

efficiency programs, a large component of DSM spending that includes all rebate 

programs. The expanded sample data set adds three utilities to the core; some estimation 

was required to fill in the less than absolutely complete information these three additional 

utilities provided. Total energy efficiency expenditures for utilities in the expanded sample 

account for roughly 25% to 35% of national expenditures. It is not known whether or not 

the sample is representative of the nation as a whole. 

In order to estimate DSM rebates for electronic ballasts, we first calculated the 

fraction of energy efficiency spending devoted to electronic ballast rebates and the average 

value of the rebate per ballast for the sample data Next, we assumed that in each year the 

average rebate value and fraction of EE spending going to ballast rebates was the same for 

the nation as in our sample. For each year, nationally-aggregated energy efficiency 

spending was multiplied by the fraction ofEE spending going to ballast rebates in our 

sample to estimate national spending on ballast rebates. Then, we divided this estimate of 

spending on ballast rebates by the average rebate per ballast to estimate the number of 

ballasts rebated for the year. The assumptions used in our estimation technique as well as 

concerns about the size of our sample data sets and whether or not they are representative 

are discussed in the last section of this report which covers uncertainty. 
Analysis of the core and expanded samples using this approach led to the following

two national estimates of the number of electronic ballast DSM rebates:

Core Sample Date[ Set Estimates (full table appears on p4;e 7)

Year 1992 1993 1994 1995 1996 1997

Estimated number of 4.58 10.8 19.4 16.1 10.5 6.34

rebates nationwide

millions

Expanded Sample Data Set Estimates (full table appe

Year 1992 1993 1994 1995 1996 1997

Estimated number of 7.02 9.36 12.8 14.4 7.10 Not

rebates nationwide Available*

millions

None of the three utilities added to the core data set were able to provide information on 1997.

Results of analysis of the core sample data set suggest that electronic ballast

rebates peaked in 1994 in terms of the number of ballasts rebated and utility spending on

rebates. Estimates of the number of rebates decline slightly in 1995 and substantially in

the last two years. Analysis of the expanded sample data set suggests the same general

trend in DSM rebates. The expanded data set indicates rebates peaked in 1995 rather than

1994. However, as is the case with the core sample, the analysis points to a sharp drop

from 1995 to 1996.

Although uncertainty certainly exists with respect to the DSM rebate estimates for

any given year, we are confident in the veracity of the general trend identified by this

analysis: DSM rebates for electronic ballasts increased in number up until recent years

when they began to decline in number. All of the sample data collected shows utilities

reducing spending on or eliminating their DSM rebates for electronic ballasts recently.

Thus, the sample data parallels the general national trend of declining electric utility

spending on DSM programs.

This study.attempts to shed some light on the impact of DSM rebates for

electronic ballasts on the ballast market by comparing trends in DSM rebates and the

market share garnered by electronic ballasts . No direct one-to-one relationship between

DSM trends and electronic ballast penetration is found . However, it does seem possible

that the declining strength of DSM rebates has contributed to the apparent levelling off or

slowed increase in the electronic ballast's penetration of the market. The rate of growth

for electronic ballasts in terms of market share has fallen since 1995 when this study

indicates that DSM rebates for electronic ballasts began to decline substantially.

ars on page 8)

2

EE-RM-97-500 COMMENT 20G

Analysis of the core and expanded samples using this approach led to the following 

two national estimates of the number of electronic ballast DSM rebates: 

c ore S amp4e l D ata S. et E . stlmates (full table appears on page 7) 

Year 1992 1993 1994 1995 1996 1997 

Estimated number of 4.58 10.8 19.4 16.1 10.5 6.34 

rebates nationwide 

Irmillions) 

E xpan d e dS ampJe IDS. ata et E . stmwtes (full table appears on page 8) 

Year 1992 1993 1994 1995 1996 1997 

IEstimated number of 7.02 9.36 12.8 14.4 7.10 Not 

rebates nationwide Available" 

Irmillions) 

" .. . None of the three utIlItIes added to the core data set were able to provlde informatIon on 1997 . 

Results of analysis of the core sample data set suggest that electronic ballast 

rebates peaked in 1994 in terms of the number of ballasts rebated and utility spending on 

rebates. Estimates of the number of rebates decline slightly in 1995 and substantially in 

the last two years. Analysis of the expanded sample data set suggests the same general 

trend in DSM rebates .. The expanded data set indicates rebates peaked in 1995 rather than 

1994. However, as is the case with the core sample, the analysis points to a sharp drop 

from 1995 to 1996. 

Although uncertainty certainly exists with respect to the DSM rebate estimates for 

any given year, we are confident in the veracity of the general trend identified by this 

analysis: DSM rebates for electronic ballasts increased in number up until recent years 

when they began to decline in number. All of the sample data collected shows utilities 

reducing spending on or eliminating their DSM rebates for electronic ballasts recently. 

Thus, the sample data parallels the general national trend of declining electric utility 

spending on DSM programs. 

This study.attempts to shed some light on the impact ofDSM rebates for 

electronic ballasts on the ballast market by comparing trends in DSM rebates and the 

market share garnered by electronic ballasts. No direct one-to-one relationship between 

DSM trends and electronic ballast penetration is found. However, it does seem possible 

that the declining strength of DSM rebates has contributed to the apparent levelling off or 

slowed increase in the electronic ballast's penetration of the market. The rate of growth 

for electronic ballasts in terms of market share has fallen since 1995 when this study 

indicates that DSM rebates for electronic ballasts began to decline substantially. 

2 
la Introduction

In May of 1997, LBNL began to collect data for a study of the impact of DemandSide Management (DSM) programs on the market for electronic fluorescent ballasts.

LBNL sought to estimate the number of rebates paid for electronic ballasts annually and

the dollar value of these rebates since their widespread emergence in the early 1990's.

This investigation into the historical trends in DSM rebates for electronic ballasts was

undertaken to inform predictions about future developments in the fluorescent ballast

market. The objective was to discern trends over time in DSM rebates and to judge their

impact on the market share garnered by electronic ballasts.

2. General Developments in DSM and EE Programs

Electric utility DSM programs grew rapidly in the late 1980's and early 1990's due

to incentives created by state regulatory programs to encourage integrated resource

planning.' Expenditures on DSM programs peaked in 1993, reaching a level of about 1%

of electric utility revenue or $2.7 billion for the nation.2 This figure dipped slightly in

1994, and fell to $2.4 billion in 1995 and $1.9 billion in 1996.3

Spending on the Energy Efficiency (EE) component of DSM programs has

followed a similar path. 4 EE spending reached a peak in 1993, levelled off, and then

declined sharply in 1995 and 1996. In 1995, EE spending fell by 12% from the year

before and in 1996 it fell by 26%. Table 1 (page 5) lists national spending on the EE

programs from 1992-1997, as well as the percentage of that national total accounted for

by the two sample data sets analyzed in this study.

The Energy Information Administration (EIA), the DOE's independent statistical

and analytical agency, reports that electric utilities are scaling back their DSM programs in

anticipation of a competitive market. "In the search for cost savings, utilities are

reassessing approaches to energy conservation and peak load reduction . In many cases,

they are opting to discontinue or reduce the emphasis on these programs."' The EIA's,

1996 annual report on DSM found that 1003 utilities out of 3,199 electric utilities in the

nation reported having DSM programs in 1996 compared to 1053 in 1995. Of the 50

utilities discontinuing DSM programs in 1996, there were 10 large and 40 small electric

utilities.6

' Eto, Joseph, December 1996, "The Past, Present, and Future of U.S. Utility Demand-Side Management

Programs," LBNL-3993 1.

2 DOE-EIA, "US. Electric Utility Demand-Side Management Programs, 1993," DOE/EIA-0589(93)

3 DOE-EIA, "U.S. Electric Utility Demand-Side Management Programs, 1994," DOE/EIA-0589(94),

DOE-ETA, "U.S. Electric Utility Demand- Side Management Programs, 1995," DOE/EIA-0589(95),

DOE-ETA, "U.S. Electric Utility Demand-Side Management Programs, 1996," DOE/EIA-0589(96)

4 In addition to energy efficiency, the other components of DSM programs are: direct load control,

interruptible load, and other load management.

s EIA Press Release, January 7, 1998, "Demand- Side Management Programs: Utilities Shift Focus,

Reduce Spending."

6 DOE-EIA, "U.S. Electric Utility Demand-Side Management Programs, 1996," DOE/EIA-0589(96)

3

EE-RM-97-500 COMMENT 20G

1. Introduction 

In May of 1997, LBNL began to collect data for a study of the impact of DemandSide Management (DSM) programs on the market for electronic fluorescent ballasts. 

LBNL sought to estimate the number of rebates paid for electronic ballasts annually and 

the dollar value of these rebates since their widespread emergence in the early 1990's. 

This investigation into the historical trends in DSM rebates for electronic ballasts was 

undertaken to inform predictions about future developments in the fluorescent ballast 

market. The objective was to discern trends over time in DSM rebates and to judge their 

impact on the market share garnered by electronic ballasts. 

2. General Developments in DSM and EE Programs 

Electric utility DSM programs grew rapidly in the late 1980's and early 1990's due 

to incentives created by state regulatory programs to encourage integrated resource 

planning. l Expenditures on DSM programs peaked in 1993, reaching a level of about 1 % 

of electric utility revenue or $2.7 billion for the nation.2 This figure dipped slightly in 

1994, and fell to $2.4 billion in 1995 and $l.9 billion in 1996.3 

Spending on the Energy Efficiency (EE) component ofDSM programs has 

followed a similar path. 4 EE spending reached a peak in 1993, levelled off, and then 

declined sharply in 1995 and 1996. In 1995, EE spending fell by 12% from the year 

before and in 1996 it fell by 26%. Table 1 (page 5) lists national spending on the EE 

programs from 1992-1997, as well as the percentage of that national total accounted for 

by the two sample data sets analyzed in this study. 

The Energy Information Administration (EIA), the DOE's independent statistical 

and analytical agency, reports that electric utilities are scaling back their DSM programs in 

anticipation of a competitive market. "In the search for cost savings, utilities are 

reassessing approaches to energy conservation and peak load reduction. In many cases, 

they are opting to discontinue or reduce the emphasis on these programs." 5 The EIA's' 

1996 annual report on DSM found that 1003 utilities oUt of3,199 electric utilities in the 

nation reported having DSM programs in 1996 compared to 1053 in 1995. Of the 50 

utilities discontinuing DSM programs in 1996, there were 10 large and 40 small electric 

utilities. 6 

1 Eto, Joseph, December 1996, "The Past, Present, and Future of U.S. Utility Demand-Side Management 

Programs," LBNL-39931. 

2 DOE-EIA, "US. Electric Utility Demand-Side Management Programs, 1993," DOEIEIA-0589(93) 

3 DOE-EIA, "US. Electric Utility Demand-Side Management Programs, 1994," OOEIEIA-0589(94), 

DOE-EIA, "U.S. Electric Utility Demand-Side Management Programs, 1995," DOEIEIA-0589(95), 

OOE-EIA, "US. Electric Utility Demand-Side Management Programs, 1996," DOEIEIA-0589(96) 

4 In addition to energy efficiency, the other components ofDSM programs are: direct load control, 

interruptible load, and other load management. 

5 EIA Press Release, January 7, 1998, "Demand-Side Management Programs: Utilities Shift Focus, 

Reduce Spending." 

6 DOE-EIA, "US. Electric Utility Demand-Side Management Programs, 1996," OOEIEIA-0589(96) 

3 
To date, only a few states (California, Rhode Island and Massachusetts) have

introduced competition in the electricity market. It seems unlikely that the national

declines in EE and DSM spending observed in recent years will reverse as more and more

utilities move from anticipating the cost-minimizing and profit-maximizing demands of a

competitive market to actually facing competition.

3. Data Collection

LBNL sought to collect as much data as possible on electronic ballast rebates from

around the nation. Data requests were made to the 15 utilities with the largest DSM ,

programs and 32 utilities overall. Six utilities provided detailed data showing both the

number of ballasts installed under rebate measures and the cost of these rebates . The six

utilities that comprise the core sample data set are : Central Maine Power Company (ME),

the Long Island Lighting Company (NY), Pacific Gas & Electric (CA), Rochester Gas &

Electric (NY), San Diego Gas and Electric (CA) and one which will be referred to as

Utility X since the utility requested that its identity remain confidential. The total spending

on energy efficiency programs of the six utilities in our core sample data set accounts for

about 15% to 20% of national spending on energy efficiency programs.

Three large utilities-Baltimore Gas & Electric (MD), Southern California Edison

(CA), and Consolidated Edison (NY) - also provided data that was useful and extensive,

but not as complete . Baltimore Gas & Electric provided annual figures on the number of

rebated ballasts installed, but not the dollar value of these rebates . Southern California

Edison provided data on yearly spending on ballasts , but not the corresponding number of

rebated ballasts. Consolidated Edison provided data that involved estimation of the

number of electronic ballasts rebated under some measures for each year , and later years

lacked specific information on the value of each rebate.

Using the average rebate value from the core sample data set, it was possible to

incorporate the information provided by the three utilities listed above to create an

expanded sample data set. In the case of Southern California Edison, the figures provided

on annual expenditures for electronic ballast rebates were divided by the average rebate

value from the core sample to estimate the number of ballasts rebated annually

(expenditures on electronic ballast rebates = $'s per rebate = total number of electronic

ballasts rebated). In the case of Baltimore Gas & Electric, the figures for the annual

number of rebates were multiplied by the average rebate value to estimate the utility's

annual spending on electronic ballast rebates (number of rebates x $'s per rebate = total

spending on electronic ballast rebates). For the years during which Consolidated Edison

provided information on the number of rebates only , the same approach was used as in the

case of Baltimore Gas & Electric. As Table 1 illustrates (next page), the nine utilities

included in the expanded data set account for roughly 25% to 35% of national

expenditures on energy efficiency programs.

4

EE-RM-97-500 COMMENT 20G

To date, only a few states (California, Rhode Island and Massachusetts) have 

introduced competition in the electricity market. It seems unlikely that the national 

declines in EE and DSM spending observed in recent years will reverse as more and more 

utilities move from anticipating the cost-minimizing and profit-maximizing demands of a 

competitive market to actually facing competition. 

3. Data Collection 

LBNL sought to collect as much data as possible on electronic ballast rebates from 

around the nation. Data requests were made to the 15 utilities with the largest DSM 

programs and 32 utilities overall. Six utilities provided detailed data showing both the 

number of ballasts installed under rebate measures and the cost of these rebates. The six 

utilities that comprise the core sample data set are: Central Maine Power Company (ME), 

the Long Island Lighting Company (NY), Pacific Gas & Electric (CA), Rochester Gas & 

Electric (NY), San Diego Gas and Electric (CA) and one which will be referred to as 

Utility X since the utility requested that its identity remain confidential. The total spending 

on energy efficiency programs of the six utilities in our core sample data set accounts for 

about 15% to 20% of national spending on energy efficiency programs. 

Three large utilities- Baltimore Gas & Electric (MD), Southern California Edison 

(CA), and Consolidated Edison (NY) - also provided data that was useful and extensive, 

but not as complete. Baltimore Gas & Electric provided annual figures on the number of 

rebated ballasts installed, but not the dollar value of these rebates. Southern California 

Edison provided data on yearly spending on ballasts, but not the corresponding number of 

rebated ballasts. Consolidated Edison provided data that involved estimation of the 

number of electronic ballasts rebated under some measures for each year, and later years 

lacked specific information on the value of each rebate. 

Using the average rebate value from the core sample data set, it was possible to 

incorporate the information provided by the three utilities listed above to create an 

expanded sample data set. In the case of Southern California Edison, the figures provided 

on annual expenditures for electronic ballast rebates were divided by the average rebate 

value from the core sample to estimate the number of ballasts rebated annually 

(expenditures on electronic ballast rebates + $'s per rebate = total number of electronic 

ballasts rebated). In the case of Baltimore Gas & Electric, the figures for the annual 

number of rebates were multiplied by the average rebate value to estimate the utility's 

annual spending on electronic ballast rebates (number of rebates x $'s per rebate = total 

spending on electronic ballast rebates). For the years during which Consolidated Edison 

provided information on the number of rebates only, the same approach was used as in the 

case of Baltimore Gas & Electric. As Table 1 illustrates (next page), the nine utilities 

included in the expanded data set account for roughly 25% to 35% of national 

expenditures on energy efficiency programs. 

4 
Table 1: Energy Efficiency Spending of Utilities in Core and Extended

Sample Data Sets as a % of Nation's Total Energy Efficiency Spending

Year National EE $'s* Core Sample % Expanded Sample %_

1992 1,205,270, 000 18% 33%

1993 1,607,952,000 14% 29%

1994 1,592, 125,000 18% 31%

1995 1,408,542,000 19% 27%

1996 1,037,758,000 18% 30%

1997 1,057,085,000** 17% NA***

as reported in the DOE/EIA Annual Reports on DSM, "U.S. Electric Utility Demand Side

Management," for 1993 , 1994, 1995, 1996 [(EIA-0589(93-96)]. No report was published for 1992; data

for the year were provided directly by EIA.

II' aggregate figure not yet available for 1997. The amount listed for 1997 is spending projected by

utilities in 1996 "Annual Electric Utility Report," Form EIA-86 1 , as reported in the DOE/EIA Annual

Report on DSM, "U.S. Electric Utility Demand Side Management for 1996," EIA -0589(96).

*** not available : none of the three utilities added to the core sample data set were able to provide

information on 1997 rebate programs.

Notes on Table 1 : The column "National EE $'s" indicates total national DSM expenditures on energy

efficiency for each year. The column "Core Sample %" lists the percentage of national EE expenditures

represented by the energy efficiency spending of the six utilities that comprise the core sample data set.

The column "Expanded Sample %" lists the percentage of national EE expenditures represented by the

nine utilities that comprise the expanded sample data set.

One data complication arose when utilities offered a rebate for an electronic ballast

in combination with a lamp or a fixture . Generally, in the case of such rebate measures,

we looked to see the value of the rebate for the ballast alone and used that as our guide.

For example, in 1994, Pacific Gas & Electric offered a $5 rebate for an electronic ballast

alone or $6 for an electronic ballast with T8 lamp . In this case, the total spending on the

combined lamp and ballast measure was multiplied by a fraction of 5/6 to approximate the

amount of the rebate attributable to the ballast.

Data collection efforts were hindered by a number of factors:

1. Frequent turn-over in personnel made it difficult to find staff with historical

knowledge;

2. Many utilities do not keep detailed historical data; lack of a standardized reporting

format made it a challenge to interpret data when it was provided.

3. Diminishing resources devoted to DSM made individuals still working on DSM less

available to respond to requests for data.

4. In one case, the utility failed to provide data despite state regulations requiring that the

data be made available upon request.

4. Analytical Methodology

Our first set of estimates is based on analysis using only the core sample data set.

We used two values derived from the core sample to estimate the number of electronic

ballasts for the nation and their dollar value annually for the years 1992 to 1997 . First, we

calculated the fraction of energy efficiency spending devoted to electronic ballast rebates

5

EE-RM-97-500 COMMENT 20G

Table 1: Energy Efficiency Spending of Utilities in Core and Extended 

Sample Data Sets as a % of Nation's Total Energy Efficiency Spendi ng 

Year National EE $'s * Core Sample % Expanded Sample % 

1992 1,205,270,000 18% 33% 

1993 1,607,952,000 14% 29% 

1994 1,592,125,000 18% 31% 

1995 1,408,542,000 19% 27% 

1996 1,037,758,000 18% 30% 

1997 1,057,085,000·· 17% NA·*· . .. as reported m the DOEIEIA Annual Reports on DSM, "U.S. Electnc UnlIty Demand Side 

Management," for 1993, 1994, 1995, 1996 [(EIA-0589(93-96)]. No report was published for 1992; data 

for the year were provided directly by EIA . 

•• aggregate figure not yet available for 1997. The amount listed for 1997 is spending projected by 

utilities in 19% "Annual Electric Utility Report," Form EIA-861, as reported in the DOEIEIA Annual 

Report on DSM, "u.s. Electric Utility Demand Side Management for 1996," EIA-0589(96) . 

...... not available: none of the three utilities added to the core sample data set were able to provide 

information on 1997 rebate programs. 

Notes on Table 1: The column "National EE $'s" indicates total national DSM expenditures on energy 

efficiency for each year. The column "Core Sample %" lists the percentage of national EE expenditures 

represented by the energy efficiency spending of the six utilities that comprise the core sample data set. 

The column "Expanded Sample %" lists the percentage of national EE expenditures represented by the 

nine utilities that comprise the expanded sample data set. 

One data complication arose when utilities offered a rebate for an electronic ballast 

in combination with a lamp or a fixture. Generally, in the case of such rebate measures, 

we looked to see the value of the rebate for the ballast alone and used that as our guide. 

For example, in 1994, Pacific Gas & Electric offered a $5 rebate for an electronic ballast 

alone or $6 for an electronic ballast with T8 lamp. In this case, the total spending on the 

combined lamp and ballast measure was multiplied by a fraction of 5/6 to approximate the 

amount of the rebate attributable to the ballast. 

Data collection efforts were hindered by a number of factors: 

1. Frequent tum-over in ·personnel made it difficult to find staff with historical 

knowledge; 

2. Many utilities do not keep detailed historical data; lack of a standardized reporting 

format made it a challenge to interpret data when it was provided. 

3. Diminishing resources devoted to DSM made individuals still working on DSM less 

available to respond to requests for data. 

4. In one case, the utility failed to provide data despite state regulations requiring that the 

data be made available upon request. 

4. Analytical Methodology 

Our first set of estimates is based on analysis using only the core sample data set. 

We used two values derived from the core sample to estimate the number of electronic 

ballasts for the nation and their dollar value annually for the years 1992 to 1997. First, we 

calculated the fraction of energy efficiency spending devoted to electronic ballast rebates 

5 
and the average value of the rebate per ballast for the sample data. Next, we assumed that

the average rebate value and fraction of EE spending going to ballast rebates was the same

for the nation as in our sample. For each year, nationally-aggregated energy efficiency

spending was multiplied by the fraction of EE spending going to ballast rebates in our

sample to estimate national spending on ballast rebates. Then, we divided this estimate of

spending on ballast rebates by the average rebate per ballast to estimate the number of

ballasts rebated for the year.

For example, in 1994, the six utilities in our core sample spent about $280 million

on energy efficiency programs and $36 million on ballast rebates, so the ballast rebates

represented 13% of total EE spending for the, sample. The $36 million was distributed

among about 3.5 million ballasts, for an average expenditure of approximately $10 per

ballast in 1994. Next, we applied the fraction of EE spending going to ballast rebates

(13%) to national spending for 1994. Nationally, EE programs amounted to about $1.6

billion in 1994, so we estimated that electronic ballast rebates amounted to about $200

million (13% of $1.6 billion) for the year. Based on an average value of $10/rebate, we

estimated that 20 million ballasts ($200 million divided by 10$/rebate) were installed under

DSM rebate measures in 1994.

A second set of estimates was calculated using the expanded data set. For the

years 1992-1994, a new average rebate value was calculated for the sample using

Consolidated Edison's data.' Otherwise, the average rebate value from the core sample

data set was used to fill out the information provided by the three extra utilities in the

expanded sample (see the previous section for a detailed explanation of this process).

Then the same approach was used; we calculated the percentage of energy efficiency

spending going to electronic ballast rebates in the sample. We applied this percentage to

national energy efficiency spending in order to calculate an estimate of national

expenditures on electronic ballast rebates. Then, we estimated the number of ballasts

rebated nationwide by dividing the estimate of national electronic ballast rebate

expenditures by the average rebate per ballast.

5. Data Analysis

5.1. Core Sample Data Set

Using the methodology described above and the core sample data set, LBNL has

calculated the following national estimates of number of electronic ballast DSM rebates

and spending on these rebates.

' The utility was excluded from the core sample data set for 1992-1994 (when complete data were

provided) because for each year some measures reported by Con Ed included estimates of ballast rebates

rather than actual figures. Although our contact at Con Ed felt fairly reliable estimates could be made,

uncertainty about the precision of estimates led us to include all the Con ED data in the expanded sample

data set rather than the core.

6

EE-RM-97-500 COMMENT 20G

and the average value of the rebate per ballast for the sample data. Next, we assumed that 

the average rebate value and fraction of EE spending going to ballast rebates was the same 

for the nation as in our sample. For each year, nationally-aggregated energy efficiency 

spending was multiplied by the fraction ofEE spending going to ballast rebates in our 

sample t9 estimate national spending on ballast rebates. Then, we divided this estimate of 

spending on ballast rebates by the average rebate per ballast to estimate the number of 

ballasts rebated for the year. 

For example, in 1994, the six utilities in our core sample spent about $280 million 

on energy efficiency programs and $36 million on ballast rebates, so the ballast rebates 

represented 13% of total EE spending for the. sample. The $36 million was distributed 

among about 3.5 million ballasts, for an average expenditure of approximately $10per 

ballast in 1994. Next, we applied the fraction ofEE spending going to ballast rebates 

(13%) to national spending for 1994. Nationally, EE programs amounted to about $1.6 

billion in 1994, so we estimated that electronic ballast rebates amounted to about $200 

million (13% of $1.6 billion) for the year. Based on an average value of$lO/rebate, we 

estimated that 20 million ballasts ($200 million divided by lO$/rebate) were installed under 

DSM rebate measures in 1994. 

A second set of estimates was calculated using the expanded data set. For the 

years 1992-1994, a new average rebate value was calculated for the sample using 

Consolidated Edison's data. 7 Otherwise, the average rebate value from the core sample 

data set was used to fill out the information provided by the three extra utilities in the 

expanded sample (see the previous section for a detailed explanation of this process). 

Then the same approach was used; we calculated the percentage of energy efficiency 

spending going to electronic ballast rebates in the sample. We applied this percentage to 

national energy efficiency spending in order to calculate an estimate of national 

expenditures on electronic ballast rebates. Then, we estimated the number of ballasts 

rebated nationwide by dividing the estimate of national electronic ballast rebate 

expenditures by the average rebate per ballast. 

5. Data Analysis 

5.1. COTe Sample Data Set 

Using the methodology described above and the core sample data set, LBNL has 

calculated the following national estimates of number of electronic ballast DSM rebates 

and spending on these rebates. 

7 The utility was excluded from the core sample data set for 1992-1994 (when complete data were 

provided) because for each year some measures reported by Con Ed included estimates of ballast rebates 

rather than actual figures. Although our contact at Con Ed felt fairly reliable estimates could be made, 

uncertainty about the precision of estimates led us to include all the Con ED data in the expanded sample 

data set rather than the core. 

6 
Table 2: Electronic Ballast DSM Rebate Estimates Derived from Core S ple

Year

% of EE $'s to

electronic ballast

rebates in the sample

National estimate of

spending on rebates

(millions of $'s)

Average $'s/rebate

in the sample _

Estimated number of

rebates nationwide

(millions)

1992 1993 1994 1995 1996 1997"

5.3% 7.3% 13% 13% 7.8% 2.0%

$63.9 $118 $207 $180 $79.9 $21.2

13.97 10.94 10.70 11.17 7.64 3.35

4.58 10.8 19.4 16.1 10.5 6.34

.1997 estimates based on data for 1/2 to 3/4 of the year. Described further below.

Notes on Table 2: The estimate of the number of rebates nationwide, listed in row four, results from

dividing the estimate of national spending on rebates in row two by the weighted average rebate value

found in row three (row four = row two / row three). The national estimate of spending on electronic

ballast rebates in row two results from multiplying national spending on rebates (listed in Table 1) by the

fraction of energy efficiency dollars going to rebates listed in row one.

The results of this analysis suggest that electronic ballast rebates peaked in 1994 in

terms of the number of ballasts rebated and utility spending on rebates. Estimates of the

number of rebates decline slightly in 1995 and substantially in the last two years. In 1996,

our analysis suggests that the number of rebates fell by about 43% and that spending on

electronic ballast rebates fell by about 55% from the year before.

The decline from 1996 to 1997 in spending on and number of DSM rebates for

electronic ballasts also appears substantial. Our estimates suggest that the number of

rebates fell by almost 40% and utility expenditures on rebates fell by about 73%.

However, analysis of data for 1997 is less certain for two reasons. First, the sample data

set includes data for less than the full year. Between 6 months and 10 months of utility

data were used to estimate the number of ballasts rebated and spending on these rebates

for the year. Secondly, the analysis for 1997 is based on projected national EE spending

as reported by utilities in their 1996 annual report to the DOE-EIA. However, in recent

years, utilities have consistently projected higher spending on DSM for the following year

than they ended up spending in reality. For example, in 1996, actual spending on DSM

fell $329 million short of the level predicted the year before (or 85% of the predicted level

of spending).' For 1995 and 1994, the figures were $171 million (or 92% of predicted)

and $288 million respectively (or 90% of predicted). If 1997 follows this pattern, then

basing our 1997 estimates on projected EE spending for the year would overstate ballast

incentives for the year.

The trend that this analysis identifies, a reduction in incentives provided by

electronic ballast DSM rebates since 1994, is confirmed by the decision of two of the

e Utility projections of DSM spending for the next year and five years later can be found in table 22 of the

EIA's annual report on DSM

7

EE-RM-97-500 COMMENT 20G

Table 1: Electronic Ballast DSM Rebate Estimates Derived from Core Sample 

Year 1992 1993 1994 1995 1996 1997" 

%ofEE $'sto 5.3% 7.3% 13% 13% 7.8% 2.0% 

electronic ballast 

rebates in the sample 

National estimate of $63.9 $118 $207 $180 $79.9 $21.2 

spending on rebates 

millions of$'s) 

Average $'s/rebate 13.97 10.94 10.70 11.17 7.64 3.35 

in the sample 

Estimated number of 4.58 10.8 19.4 16.1 10.5 6.34 

rebates nationwide 

millions) 

*1997 estimates based on data for Y2 to % of the year. Described further below. 

Notes on Table 2: The estimate of the number of rebates nationwide, listed in row four, results from 

dividing the estimate of national spending on rebates in row two by the weighted average rebate value 

found in row three (row four = row two I row three). The national estimate of spending on electronic 

ballast rebates in row two results from multiplying national spending on rebates Oisted in Table 1) by the 

fraction of energy efficiency dollars going to rebates listed in row one. 

The results of this analysis suggest that electronic ballast rebates peaked in 1994 in 

terms of the number of ballasts rebated and utility spending on rebates. Estimates of the 

number of rebates decline slightly in 1995 and substantially in the last two years. In 1996, 

our analysis suggests that the number of rebates fell by about 43% and that spending on 

electronic ballast rebates fell by about 55% from the year before. 

The decline from 1996 to 1997 in spending on and number of DSM rebates for 

electronic ballasts also appears substantial. Our estimates suggest that the number of 

rebates fell by almost 40% and utility expenditures on rebates fell by about 73%. 

However, analysis of data for 1997 is less certain for two reasons. First, the sample data 

set includes data for less than the full year. Between 6 months and 10 months of utility 

data were used to estimate the number of ballasts rebated and spending on these rebates 

for the year. Secondly, the analysis for 1997 is based on projected national EE spending 

as reported by utilities in their 1996 annual report to the DOE-EIA. However, in recent 

years, utilities have consistently projected higher spending on DSM for the following year 

than they ended up spending in reality. For example, in 1996, actual spending on DSM 

fell $329 million short of the level predicted the year before (or 85% of the predicted level 

ofspending).8 For 1995 and 1994, the figures were $171 million (or 92% of predicted) 

and $288 million respectively (or 90% of predicted). If 1997 follows this pattern, then 

basing our 1997 estimates on projected EE spending for the year would overstate ballast 

incentives for the year. 

The trend that this analysis identifies, a reduction in incentives provided by 

electronic ballast DSM rebates since 1994, is confirmed by the decision of two of the 

8 Utility projections ofDSM spending for the next year and five years later can be found in table 22 of the 

EIA's annual report on DSM 

7 
smaller utilities in our sample to end their electronic ballast rebate programs in recent

years. In 1995, the Central Maine Power Company stopped offering electronic ballast

rebates. Rochester Gas & Electric ended their incentives program for ballasts in 1996.

5.2. Expanded Sample Data Set

Using the expanded data set, LBNL calculated a second set of national estimates

of the number of electronic ballasts rebated and spending on these rebates.

Table 3: Electronic Ballast Rebate Estimates Derived from Expanded Sa

Year

% of EE $'s to electronic

ballast rebates in the sample

ational estimate of

spending on rebates

(millions of $'s

Average $'s/rebate

in the sample

Estimated number of

rebates nationwide

1992 1993 1994 1995 1996

11% 5.7% 8.4% 11.4% 5.2%

$129 $91.0 $133 $161 $54.2

18.40 9.73 10.39 11.17 7.64

7.02 9.36 12.8 14.4 7.10

Notes on Table 3: The estimate of the number of rebates nationwide , listed in row four, results from

dividing the estimate of national spending on rebates in row two by the weighted average rebate value

found in row three (row four = row two -^- row three). The national estimate of spending on electronic

ballast rebates in row two results from multiplying national spending on rebates (listed in Table 1) by the

fraction of energy efficiency dollars going to rebates listed in row one. Recall that none of the utilities

added to the core sample were able to provide any information on 1997. Thus, there is no new estimate

for that year.

Analysis of the expanded sample data set suggests that DSM rebates for electronic

ballasts peaked in 1995 rather than 1996. Despite this difference, estimates from the

expanded sample generally support the pattern that emerged from analysis of the core

sample. As in the case of the core sample, analysis of the expanded sample indicates a

sharp fall in DSM rebates from 1995 to 1996. None of the utilities added to the core

sample to create the expanded sample were able to provide any data for 1997.

One notable aspect of the expanded sample data set is the large value calculated

for the weighted average value per rebate in 1992 . This reflects the fact that Consolidated

Edison rebated over 1 million ballasts for the year for $25 to $35 per ballast based on the

number of lamps the ballast accommodated . Consolidated Edison's electronic ballast

rebates accounted for more than 40% of the ballast rebates in the expanded sample for

1992. By the following year, the utility 's rebate levels had fallen into line with others in

the sample, ranging from $6 to $15 per ballast.

Figure 1 (next page) presents a comparison of the DSM rebate estimates derived

from the core sample data set and the expanded sample data set along with figures on

shipments of electronic ballasts in the U . S. as reported by the National Electrical

Manufacturers Association. It should be noted that the 1997 values in Figure 1 are both

based on incomplete data for that year.

8

EE-RM-97-500 COMMENT 20G

smaller utilities in our sample to end their electronic ballast rebate programs in recent 

years. In 1995, the Central Maine Power Company stopped offering electronic ballast 

rebates. Rochester Gas & Electric ended their incentives program for ballasts in 1996. 

5.2. Expanded Sample Data Set 

Using the expanded data set, LBNL calculated a second set of national estimates 

of the number of electronic ballasts rebated and spending on these rebates. 

Table 3: Electronic Ballast Rebate Estimates Derivedfrom EXRanded Sample 

Year 1992 1993 1994 1995 1996 

% of EE $' s to electronic 11% 5.7% 8.4% 11.4% 5.2% 

ballast rebates in the sample 

~ational estimate of $129 $91.0 $133 $161 $54.2 

spending on rebates 

millions of $'s) 

Average $'s/rebate 18.40 9.73 10.39 11.17 7.64 

in the sample 

Estimated number of 7.02 9.36 12.8 14.4 7.10 

rebates nationwide 

Notes Oil Table 3: The estunate of the number of rebates natlonWlde, hsted m row four, results from 

dividing the estimate of national spending on rebates in row two by the weighted average rebate value 

found in row three (row four = row two + row three). The national estimate of spending on electronic 

ballast rebates in row two results from multiplying national spending on rebates Oisted in Table 1) by the 

fraction of energy efficiency dollars going to rebates listed in row one. Recall that none of the utilities 

added to the core sample were able to provide any information on 1997. Thus, there is no new estimate 

for that year. 

Analysis of the expanded sample data set suggests that DSM rebates for electronic 

ballasts peaked in 1995 rather than 1996. Despite this difference, estimates from the 

expanded sample generally support the pattern that emerged from analysis of the core 

sampl~. As in the case of the core sample, analysis of the expanded sample indicates a 

sharp fall in DSM rebates from 1995 to 1996. None of the utilities added to the core 

sample to create the expanded sample were able to provide any data for 1997. 

One notable aspect of the expanded sample data set is the large value calculated 

for the weighted average value per rebate in 1992. This reflects the fact that Consolidated 

Edison rebated over 1 million ballasts for the year for $25 to $35 per ballast based on the 

number oflamps the ballast accommodated. Consolidated Edison's electronic ballast 

rebates accounted for more than 40% of the ballast rebates in the expanded sample for 

1992. By the following year, the utility's rebate levels had 'fallen into line with others in 

the sample, ranging from $6 to $15 per ballast. 

Figure 1 (next page) presents a comparison of the DSM rebate estimates derived 

from the core sample data set and the expanded sample data set along with figures on 

shipments of electronic ballasts in the U.S. as reported by the National Electrical 

Manufacturers Association. It should be noted that the 1997 values in Figure 1 are both 

based on incomplete data for that year. 

8 
Figure 1: Comparing DSM Rebate Estimates --

Core vs. Expanded Samples (Plus Shipment Data)

0-

1992 1993 1994 • 1995 1996 1997

Year

-&-core sample estimates ( millions)

-expanded sample estimates ( millions)

...• electronic ballast shipments ( millions)

6. Discussion: Market Impact

Here we combine this study's national electronic ballast DSM rebate estimates

with data provided by NEMA on domestic ballast shipments in the US in order to gain

some insight into the impact of DSM on the ballast market. In particular, we look to see if

the reduction in the number of DSM rebates for electronic ballasts has had a discernible

effect. It seems possible that this reduction in DSM rebates has contributed to the

apparent levelling off or slowed increase in the electronic ballast's penetration of the

market. The rate of growth for electronic ballasts in terms of market share has fallen since

1995 when this study indicates that DSM rebates for electronic ballasts began to decline

substantially. From 1995 to 1996, the share of the market going to electronic ballasts fell

by about 2% (see Table 4). Their market share increased from 1996 to 1997 by about

6%. Still, this gain does not compare to the rate of changes from 1993 to 1994 and from

1994 to 1995, when the gains were 13% and 20% respectively.

9

EE-RM-97-500 COMMENT 20G

~ c 

(I) 

E 

Q. 

:c 

rJ) 

!! 

en 

S 

ItS 

.c 

~ 

'0 

... 

(I) 

.c 

E 

::I 

Z 

40 

35 

30 

25 

20 

15 

10 

5 

0 

Figure 1: Comparing DSM Rebate Estimates --

Core "s. Expanded Samples (Plus Shipment Data) 

..... , .. 

........... "::::: 

...... .... 

1992 1993 1994 , 1995 1996 1997 

Year 

--+-core sample estimates (millions) 

~expanded sample estimates (millions) 

.... :::.: .... electronic ballast shipments (millions) 

6. Discussion: Market Impact 

Here we combine this study's national electronic ballast DSM rebate estimates 

with data provided by NEMA on domestic ballast shipments in the US in order to gain 

some insight into the impact of DSM on the ballast market. In particular, we look to see if 

the reduction in the number of DSM rebates for electronic ballasts has had a discernible 

effect. It seems possible that this reduction in DSM rebates has contributed to the 

apparent levelling off or slowed increase in the electronic ballast's penetration of the 

market. The rate of growth for electronic ballasts in terms of market share has fallen since 

1995 when this study indicates that DSM rebates for electronic ballasts began to decline 

substantially. From 1995 to 1996, the share of the market going to electronic ballasts fell 

by about 2% (see Table 4). Their market share increased from 1996 to 1997 by about 

6%. Still, this gain does not compare to the rate of changes from 1993 to 1994 and from 

1994 to 1995, when the gains were 13% and 20% respectively. 

9 
Table d Assessing Market Qacts ® DSM

Year Core Sample

DSM Rebate

Estimates

(millions)

Expanded

Sample DSM

Rebate Estimates

(millions)

Electronic

Ballast

Shipments*

(millions)

Electronic

Ballast Market

Share (% of

Ballast Market)

Rate of Change

in Market Share

1993 10.8 9.36 22.914 37.0%

1994 19.4 12.8 25.993 41.8% + 13%

1995 16.1 16.0 33.101 50.1% +20%

1996 10.5 7.10 30.317 49.1% - 2%

1997 6.34 Not Available 34.95444 52.1% +6%

- shipment data provided courtesy of NEMA

1997 shipment figures estimated by NEMA based on 6 months of data

Table 5 shows ballast market data in conjunction with the estimates of DSM

rebates for electronic ballasts derived from our core sample and expanded sample.

Table S: The Ballast Market with DSM Estimates

Year gnetic

allast

hipments*

millions)

Electronic

Ballast

Shipments

(millions)

Total

Ballast

Shipments

(millions)

Core Sample Estimate of

DSM Rebates - 000's

(% of elec . shipments )

Expanded Sample Estimate

of DSM Rebates - 000's

(% of elec. shipments )

1993 39.091 22.914 62.005 10.8 (47%) 9.36 (41%)

1994 36.154 25.993 62.147 19.4 (75%) 12. 8 (49%)

1995 33.020 33.101 66.121 16.1 490/6) 16.0 (48%)

1996 31.475 30.317 61.792 10.5 (35%) 7.10 (23%)

1997 32.180** 34.954** 67.134** 6.34 (18%) Not Available

shipment data provided courtesy of NEMA

'* 1997 shipment figures estimated by NEMA based on 6 months of data

While it does seem that a decline in the number of electronic ballast DSM rebates

may have contributed to the slowing of the rate of growth in the electronic ballast's

market share, this study does not show a direct positive relationship between the level of

DSM rebates and the share of the ballast market going to electronics. Clearly, DSM

rebates are one of several interrelated factors that determine the market share of electronic

ballasts over time. A more complete data set for a longer period of time would improve

our understanding of DSM trends and their impact on the ballast market.

Figure 2 (below) presents a graphical analysis of trends in electronic ballast market

share and DSM rebate estimates, which are reported as the percentage of electronic ballast

shipments for the year. DSM rebate estimates derived from both the core sample and

expanded sample are graphed. The graph demonstrates that there is not a positive one-toone correlation between DSM rebates and the market share garnered by electronic

ballasts. The graph also shows the declining percentage of electronic ballast shipments

rebated followed by the leveling off or decreased growth rate in electronic ballast market

share.

10

EE-RM-97-500 COMMENT 20G

Table 4: Assessing Market Effects of DSM 

Year Core Sample Expanded Electronic Electronic Rate of Change 

DSMRebate SampleDSM Ballast Ballast Market in Market Share 

Estimates Rebate Estimates Shipments " Share (%of 

(millions) (millions) (millions) Ballast Market) 

1993 10.8 9.36 22.914 37.0% 

1994 19.4 12.8 25.993 41.8% + 13% 

1995 16.1 16.0 33.101 50.1% +20% 

1996 10.5 7.10 30.317 49.1% -2% 

1997 6.34 Not Available 34.954" 52.1% +6% 

" shipment data provided courtesy of NEMA 

""1997 shipment figures estimated by NEMA based on 6 months of data 

Table 5 shows ballast market data in conjunction with the estimates ofDSM 

rebates for electronic ballasts derived from our core sample and expanded sample. 

Table 5: The Ballast Market with DSM Estimates 

Year ~gnetic Electronic Total Core Sample Estimate of Expanded Sample Estimate 

~allast Ballast Ballast DSM Rebates - OOO's ofDSM Rebates - OOO's 

~hipments" Shipments Shipments (% of e1ec. shipments) (% of e1ec. shipments) 

millions) • (millions) , (millions) 

1993 39.091 22.914 62.005 10.8 (47%) 9.36 (41%) 

1994 36.154 25.993 62.147 19.4 (75%) 12.8 (49%) 

1995 33.020 33.101 66.121 16.1 (49%) 16.0 (48%) 

1996 31.475 30.317 61.792 10.5 (35%) 7.10 (23%) 

1997 32.180" 34.954" 67.134" 6.34 (18%) Not Available , 

shipment data proVIded courtesy of NEMA 

"1997 shipment figures estimated by NEMA based on 6 months of data 

While it does seem that a decline in the number of electronic ballast DSM rebates 

may have contributed to the slowing of the rate of growth in the electronic ballast's 

market share, this study does not show a direct positive relationship between the level of 

DSM rebates and the share of the ballast market going to electronics. Clearly, DSM 

rebates are one of several interrelated factors that determine the market share of electronic 

ballasts over time. A more complete data set for a longer period of time would improve 

our understanding ofDSM trends and their impact on the ballast market. 

Figure 2 (below) presents a graphical analysis of trends in electronic ballast market 

share and DSM rebate estimates, which are reported as the percentage of electronic ballast 

shipments for the year. DSM rebate estimates derived from both the core sample and 

expanded sample are graphed. The graph demonstrates that there is not a positive one-toone correlation between DSM rebates and the market share garnered by electronic 

ballasts. The graph also shows the declining percentage of electronic ballast shipments 

rebated followed by the leveling off or decreased growth rate in electronic ballast market 

share. 

10 
Figure 2: % of Electronic Ballast Shipments Rebated and

Market Share of Electronic Ballasts Over Time

80

70

60

50

40

30

20

10

• A

1993 1994 1995

Year

1996

---I electronic ballast market share

• % of elec. shipments with rebate (core estimates)

% of elec. shipments with rebate (expanded estimates)

7. Uncertainty

1997

We are confident in the veracity of the general trend identified by this analysis:

DSM rebates for electronic ballasts increased in number up until recent years when they

began to decline in number . All of the sample data collected shows utilities reducing or

eliminating their DSM rebates for electronic ballasts recently . Thus, the sample data

parallels the general national trend toward smaller DSM programs discussed in section

two. A detailed summary of the sample data is provided in Table 6 at the end of this

section so that the reader can observe the variance and trends over time for the individual

utilities in our sample data. However, despite LBNL's efforts to maximize the amount of

data incorporated in this analysis, only a relatively small sample size was successfully

collected.

11

EE-RM-97-500 COMMENT 20G

80 

e 

CIS 70 

.c 

en 

-II) 

.:.c: 

... 60 CIS 

:liE 

oa 

-'C 50 

II) 

--

2l~ II) 

a:: 40 

CIl 

-

C 

II) 

E 

Q. 30 

:E 

en 

'0 20 co ~ 

10 

Figure 2: % of Electronic Ballast Shipments Rebated and 

Market Share of Electronic Ballasts Over Time 

/ 

!J!i(' ••••••••• ,:,:: •. , - • ~~ ~: '- , 

,,:::-' . . . . ~-------- ". ''-. .----- " 

1993 1994 1995 

Year 

---If--electronic ballast market share 

. 

" 

1996 

- .. - % of elec. shipments with rebate (core estimates) 

.. '::'''' . % of elec. shipments with rebate (expanded estimates) 

7. Uncertainty 

We are confident in the veracity of the general trend identified by this analysis: 

1997 

DSM rebates for electronic ballasts increased in number up until recent years when they 

began to decline in number. All of the sample data collected shows utilities reducing or 

eliminating their DSM rebates for electronic ballasts recently. Thus, the sample data 

parallels the general national trend toward smaller DSM programs discussed in section 

two. A detailed summary of the sample data is provided in Table 6 at the end of this 

section so that the reader can observe the variance and trends over time for the individual 

utilities in our sample data. However, despite LBNL's efforts to maximize the amount of 

data incorporated in this analysis, only a relatively small sample size was successfully 

collected. 

11 
It is not known whether or not the sample is representative of the nation as a

whole. To provide some idea of the relative size of the sample with respect to national

rebate programs, we have compared the total energy efficiency spending of the utilities

included in the sample data with national spending. The core sample represents about

15% to 20% of national expenditures on energy efficiency; the expanded sample accounts

for roughly 25% to 35% of national expenditures on energy efficiency.

Generally, our attempts to increase the sample size were frustrated by the inability

of utilities to provide historical data . However, in some cases, utilities had trouble

providing more recent data . The Long Island Lighting Company was unable to provide

data for 1996 or 1997, thus reducing the core sample by one large utility for those years

and exacerbating the small sample size problem . Moreover, none of the additional utilities

in the expanded sample were able to deliver any information on 1997.

It is not known whether the estimates derived from the expanded sample are more

or less certain than the core sample estimates. The expanded sample allows the analysis to

incorporate some additional information- the number of ballasts rebated by Baltimore Gas

& Electric and Consolidated Edison, and spending on ballast rebates by San Diego Gas &

Electric- but it also requires an additional assumption that each additional utility offered

rebates at the value calculated for the core sample.

The sample size is important because observations from the sample data are scaled

up based on national energy efficiency spending to estimate for the U . S. as a whole the

number of DSM rebates for electronic ballasts. The estimation technique assumes that the

average rebate value and the fraction of energy efficiency spending on rebates calculated

for the sample are the same as those for the United States as a whole. We recognize that

it is unlikely that the national values are the same as those observed in either of the two

samples. However, the amount of divergence between the assumed and actual values is

uncertain.

There are two reasons to believe that this study's estimates underestimate the

impact of DSM rebates on the market:

(1) Participant spillover effect

Participant spillover, or the "free driver" effect, refers to the lasting impact on

those who have taken advantage of rebates. Even if rebates are no longer

available, these participant are more likely to buy electronic ballasts in the future

because any doubts or uncertainty about the new technology will have been

dispelled.

(2) Non-participant spillover effect

Non-participant spillover points out that lower prices would likely follow from the

expanded demand and supply that rebates cause . In turn, these lower prices will

likely encourage some additional consumers to purchase electronic ballasts even if

they don't receive rebates.

While the two factors named above would lead to the conclusion that the estimates in this

study may underestimate the impact of DSM rebates, the presence of a "free rider" effect

suggests the opposite . The "free rider" principle recognizes that some consumers who

12

EE-RM-97-500 COMMENT 20G

It is not known whether or not the sample is representative of the nation as a 

whole. To provide some idea of the relative size of the sample with respect to national 

rebate programs, we have compared the total energy efficiency spending of the utilities 

included in the sample data with national spending. The core sample represents about 

15% to 20% of national expenditures on energy efficiency; the expanded sample accounts 

for roughly 25% to 35% of national expenditures on energy efficiency. 

Generally, our attempts to increase the sample size were frustrated by the inability 

of utilities to provide historical data. However, in some cases, utilities had trouble 

providing more recent data. The Long Island Lighting Company was unable to provide 

data for 1996 or 1997, thus reducing the core sample by one large utility for those years 

and exacerbating the small sample size problem. Moreover, none of the additional utilities 

in the expanded sample were able to deliver any information on 1997. 

It is not known whether the estimates derived from the expanded sample are more 

or less certain than the core sample estimates. The expanded sample allows the analysis to 

incorporate some additional information- the number of ballasts rebated by Baltimore Gas 

& Electric and Consolidated Edison, and spending on ballast rebates by San Diego Gas & 

Electric- but it also requires an additional assumption that each additional utility offered 

rebates at the value calculated for the core sample. 

The sample size is important because observations from the sample data are scaled 

up based on national energy efficiency spending to estimate for the U.S. as a whole the 

number ofDSM rebates for electronic ballasts. The estimation technique assumes that the 

average rebate value and the fraction of energy efficiency spending on rebates calculated 

for the sample are the same as those for the United States as a whole. We recognize that 

it is unlikely that the national values are the same as those observed in either of the two 

samples. However, the amount of divergence between the assumed and actual values is 

uncertain. 

There are two reasons to believe that this study's estimates underestimate the 

impact ofDSM rebates on the market: 

(1) Participant spillover effect 

Participant spillover, or the "free driver" effect, refers to the lasting impact on 

those who have taken advantage of rebates. Even if rebates are no longer 

available, these participant are more likely to buy electronic ballasts in the future 

because any doubts or uncertainty about the new technology will have been 

dispelled. 

(2) Non-participant spillover effect 

Non-participant spillover points out that lower prices would likely follow from the 

expanded demand and supply that rebates cause. In tum, these lower prices will 

likely encourage some additional consumers to purchase electronic ballasts even if 

they don't receive rebates. 

While the two factors named above would lead to the conclusion that the estimates in this 

study may underestimate the impact of DSM rebates, the presence of a "free rider" effect 

suggests the opposite. The "free rider" principle recognizes that some consumers who 

12 
purchase electronic ballasts and receive a rebate would have purchased them even if the

rebate had not been offered. This study will not resolve which of these two countervailing

forces is greatest.

(Table 6, Detailed Summary of Sample Data, next page.)

13

EE-RM-97-500 COMMENT 20G

purchase electronic ballasts and receive a rebate would have purchased them even if the 

rebate had not been offered. This study will not resolve which of these two countervailing 

forces is greatest. 

(Table 6, Detailed Summary of Sample Data, next page.) 

13 
Year 1 1992 1 1993 1 1 994 1 1995 1 1996 1 1997

CORE SAMPLE DATA SET

(1) Central Maine Power Company

# of rebates

19.21

9%

44,641 52,687

$'s/rebate

% of EE $'s 6%

21.63

(2) Long Island Lighting Company

# of rebates

10.11

1%

90,659 273,005

$'s/rebate

% of EE $'s 5%

(3) Pacific Gas & Electric

53,895

14%

280,711

4.28

8%

# of rebates 333,801 659,643 2,346,229

$'s/rebate 7.42 6.16 5.56

of EE $'s 2% 4% 10%

(4) Rochester Gas & Electric

# of rebates

$'s/rebate

%ofEE $'s

25,081

13.60

4%

(5) San Diego Gas & Electric

# of rebates

$'s/rebate

% of EE $'s

261,408

22.80

17%

1.00

41,549

11.98

5%

356,251

21.14

29%

(6) Utility X (requested anonymity)

# of rebates

14.01

7%

87,852 169,654

$'s/rebate

% of EE $'s 6%

EXPANDED SAMPLE DATA SET

(7) Baltimore Gas & Electric

# of rebates

$'s/rebated

% of EE $'s

166,520

10.87

13%

(8) Consolidate Edison

# of rebates

$'s/rebate

% of EE $'s

1,064,242

26.87

30%

20.56

221,267

9.82

9%

617,986

8.79

5%

(9) Southern California Edison

# of rebates

10.87 9.82

1%

25,042 132,493

$'s/rebate s

%ofEE $'s

9.83

7%

304,229

41.58

42%

358,098

21.02

25.44

'NA: Not Available

Source: All data provided directly by utilities.

0.5%

10.29

42,310

1%

13.26

81,592

11%

10.29

347,333

8%

a 1997 figures estimated using data through 15 October 1997.

b1997 figures estimated using data through 1 July 1997.

1997 figures estimated using data through 1 October 1997.

d These values are taken from the weighted average value calculated for the core sample.

e Values for 1995 and 1996 taken from weighted average value calculated for the core sample. For those

years the utility provided estimates of the number of ballasts rebated, but not the corresponding

expenditures.

The number of rebates is estimated using the figures on yearly spending on ballast rebates provided by

SCE and the average rebate value calculated for the core sample.

6%

Table 6: Detailed ,Su ry of ,Sample Data

0 0 0

0 0 0

0 0 0

235,182 NA' NA

1.20 NA NA

2% NA NA

1,485,346 1,318,372 944,104

5.1 4.60 2.02aa

8% 8% 2%a

16,464 0 0

5.88 0 0

2% 0 0

645,699 304,067 48,000

20.74 13.57 73-6-OF

34% 9% ^

695,679 248,959 103,000

18.60 16.53 10.68c

13% 9% 2% C

699,129 185,434 NA

9.81 7.64 NA

22% 5% NA

88,387 66,725 NA

9.81 7.64 NA

2% 1% NA

14,015 12,268 NA

9.81 7.64 NA

0.4% 0.2% NA

14

EE-RM-97-500 COMMENT 20G

Table 6: Detailed Summary of Sample Data 

Year 1992 1993 

CORE SAMPLE DATA SET 

(1) Central Maine Power Company 

# of rebates 44,641 52,687 

$'s/rebate 19.21 21.63 

%ofEE$'s 6% 9% 

(2) Long Island Lh!hting Company 

# of rebates 90,659 273,005 

$'slrebate 10.11 1.00 

%ofEE$'s 5% 1% 

(3) Pacific Gas & Electric 

# of rebates 333,801 659,643 

$'slrebate 7.42 6.16 

%ofEE$'s 2% 4% 

(4) Rochester Gas & Electric 

# of rebates 25,081 41,549 

$'slrebate 13.60 11.98 

%ofEE$'s 4% 5% 

(5) San Diego Gas & Electric 

# of rebates 261,408 356,251 

$'slrebate 22.80 21.14 

%ofEE$'s 17% 29% 

(6) Utility X (requested anonymity) 

# of rebates 87,852 169,654 

$'slrebate 14.01 20.56 

%ofEE$'s 6% 7% 

EXPANDED SAMPLE DATA SET 

(7) Baltimore Gas & Electric 

# of rebates 166,520 221,267 

$'slrebated 10.87 9.82 

%ofEE $'s 13% 9% 

(8) Consolidate Edison 

# of rebates 1,064,242 617,986 

$' slrebate e 26.87 8.79 

%ofEE $'s 30% 5% 

(9) Southern California Edison 

# of rebates f 25,042 132,493 

$' slrebate g 10.87 9.82 

%ofEE $'s 6% 1% .. . Source: All data proVIded directly by utilitIes . 

*NA: Not Available 

1994 

53,895 

25.44 

14% 

280,711 

4.28 

8% 

2,346,229 

5.56 

10% 

55,470 

9.83 

7% 

304,229 

41.58 

42% 

358,098 

21.02 

8% 

347,333 

10.29 

11% 

81,592 

13.26 

1% 

42,310 

10.29 

0.5% 

a 1997 figures estimated using data through 15 October 1997. 

b1997 figures estimated using data through 1 July 1997. 

c 1997 figures estimated using data through 1 October 1997. 

1995 1996 

0 0 

0 0 

0 0 

235,182 NA* 

1.20 NA 

2% NA 

1,485,346 1,318,372 

5.16 4.60 

8% 8% 

16,464 0 

5.88 0 

2% 0 

645,699 304,067 

20.74 13.57 

34% 9% 

695,679 248,959 

18.60 16.53 

13% 9% 

699,129 185,434 

9.81 7.64 

22% 5% 

88,387 66,725 

9.81 7.64 

2% 1% 

14,015 12,268 

9.81 7.64 

0.4% 0.2% 

d These values are taken from the weighted average value calculated for the core sample. 

1997 

0 

0 

0 

NA 

NA 

NA 

944,104 

2.028 

2%8 

0 

0 

0 

48,000 

13.60b 

2%b 

103,000 

10.68c 

2%C 

NA 

NA 

NA 

NA 

NA 

NA 

NA 

NA 

NA 

e Values for 1995 and 1996 taken from weighted average value calculated for the core sample. For those 

years the utility provided estimates of the number of ballasts rebated, but not the corresponding 

expenditures. 

f The number of rebates is estimated using the figures on yearly spending on ballast rebates provided by 

SeE and the average rebate value calculated for the core sample. 

14 
g These values are taken from the weighted average value calculated for the core sample.

15

EE-RM-97-500 COMMENT 20G

g These values are taken from the weighted average value calculated for the core sample. 

15