CALIFORNIA STANDARD PRACTICE

MANUAL:

ECONOMIC ANALYSIS OF DEMAND-SIDE

PROGRAMS AND PROJECTS

July 2002

Gray Davis, Governor
1

Table of Contents

Page

Chapter 1....................................................................................................................................1

Basic Methodology.....................................................................................................................1

Background............................................................................................................................1

Demand-Side Management Categories and Program Definitions...........................................2

Basic Methods........................................................................................................................3

Balancing the Tests.................................................................................................................6

Limitations: Externality Values and Policy Rules....................................................................6

Externality Values...................................................................................................................6

Policy Rules............................................................................................................................6

Chapter 2....................................................................................................................................8

Participant Test...........................................................................................................................8

Definition................................................................................................................................8

Benefits and Costs..................................................................................................................8

How the Results Can be Expressed........................................................................................9

Strengths of the Participant Test.............................................................................................9

Weaknesses of the Participant Test.........................................................................................9

Formulae...............................................................................................................................10

Chapter 3..................................................................................................................................13

The Ratepayer Impact Measure Test.........................................................................................13

Definition..............................................................................................................................13

Benefits and Costs................................................................................................................13

How the Results can be Expressed.......................................................................................13

Strengths of the Ratepayer Impact Measure (RIM) Test.......................................................14

Weaknesses of the Ratepayer Impact Measure (RIM) Test..................................................14

Chapter 4..................................................................................................................................18

Total Resource Cost Test..........................................................................................................18

Definition..............................................................................................................................18

How the Results Can be Expressed......................................................................................19

Strengths of the Total Resource Cost Test............................................................................20

Weakness of the Total Resource Cost Test...........................................................................21

Formulas...............................................................................................................................21

Chapter 5..................................................................................................................................23

Program Administrator Cost Test.............................................................................................23

Definition..............................................................................................................................23

Benefits and Costs................................................................................................................23

How the Results Can be Expressed......................................................................................23

Strengths of the Program Administrator Cost Test...............................................................24

Weaknesses of the Program Administrator Cost Test...........................................................24

Formulas...............................................................................................................................24

Appendix A...............................................................................................................................26

Inputs to Equations and Documentation...................................................................................26

Appendix B...............................................................................................................................28

Summary of Equations and Glossary of Symbols....................................................................28

Basic Equations....................................................................................................................28

Participant Test.................................................................................................................28

Ratepayer Impact Measure Test........................................................................................28
2

Total Resource Cost Test..................................................................................................28

Program Administrator Cost Test.....................................................................................28

Benefits and Costs................................................................................................................29

Participant Test.................................................................................................................29

Ratepayer Impact Measure Test........................................................................................29

Total Resource Cost Test..................................................................................................29

Program Administrator Cost Test.....................................................................................30

Glossary of Symbols............................................................................................................30

Appendix C...............................................................................................................................33

Derivation of Rim Lifecycle Revenue Impact Formula..............................................................33

Rate Impact Measure............................................................................................................33
1

Chapter 1

Basic Methodology

Background

Since the 1970s, conservation and load management programs have been promoted by the

California Public Utilities Commission (CPUC) and the California Energy Commission (CEC)

as alternatives to power plant construction and gas supply options. Conservation and load

management (C&LM) programs have been implemented in California by the major utilities

through the use of ratepayer money and by the CEC pursuant to the CEC legislative mandate to

establish energy efficiency standards for new buildings and appliances.

While cost-effectiveness procedures for the CEC standards are outlined in the Public Resources

Code, no such official guidelines existed for utility-sponsored programs. With the publication

of the Standard Practice for Cost-Benefit Analysis of Conservation and Load Management

Programs in February 1983, this void was substantially filled. With the informal "adoption"

one year later of an appendix that identified cost-effectiveness procedures for an "All

Ratepayers" test, C&LM program cost effectiveness consisted of the application of a series of

tests representing a variety of perspectives-participants, non-participants, all ratepayers, society,

and the utility.

The Standard Practice Manual was revised again in 1987-88. The primary changes (relative to

the 1983 version), were: (1) the renaming of the “Non-Participant Test” to the “Ratepayer

Impact Test“; (2) renaming the All-Ratepayer Test” to the “Total Resource Cost Test.”; (3)

treating the “Societal Test” as a variant of the “Total Resource Cost Test;” and, (4) an

expanded explanation of “demand-side” activities that should be subjected to standard

procedures of benefit-cost analysis.

Further changes to the manual captured in this (2001) version were prompted by the cumulative

effects of changes in the electric and natural gas industries and a variety of changes in

California statute related to these changes. As part of the major electric industry restructuring

legislation of 1996 (AB1890), for example, a public goods charge was established that ensured

minimum funding levels for “cost effective conservation and energy efficiency” for the 1998-

2002 period, and then (in 2000) extended through the year 2011. Additional legislation in 2000

(AB1002) established a natural gas surcharge for similar purposes. Later in that year, the

Energy Security and Reliability Act of 2000 (AB970) directed the California Public Utilities

Commission to establish, by the Spring of 2001, a distribution charge to provide revenues for a

self generation program and a directive to consider changes to cost-effectiveness methods to

better account for reliability concerns.

In the Spring of 2001, a new state agency — the Consumer Power and Conservation Financing

Authority — was created. This agency is expected to provide additional revenues in the form of

state revenue bonds that could supplement the amount and type of public financial resources to

finance energy efficiency and self generation activities.

The modifications to the Standard Practice Manual reflect these more recent developments in

several ways. First, the “Utility Cost Test” is renamed the “Program Administrator Test” to

include the assessment of programs managed by other agencies. Second, a definition of self

generation as a type of “demand-side” activity is included. Third, the description of the

various potential elements of “externalities” in the Societal version of the TRC test is
2

expanded. Finally the limitations section outlines the scope of this manual and elaborates upon

the processes traditionally instituted by implementing agencies to adopt values for these

externalities and to adopt the the policy rules that accompany this manual.

Demand-Side Management Categories and Program

Definitions

One important aspect of establishing standardized procedures for cost-effectiveness evaluations

is the development and use of consistent definitions of categories, programs, and program

elements.

This manual employs the use of general program categories that distinguish between different

types of demand-side management programs, conservation, load management, fuel substitution,

load building and self-generation. Conservation programs reduce electricity and/or natural gas

consumption during all or significant portions of the year. ‘Conservation’ in this context

includes all ‘energy efficiency improvements’. An energy efficiency improvement can be

defined as reduced energy use for a comparable level of service, resulting from the installation

of an energy efficiency measure or the adoption of an energy efficiency practice. Level of

service may be expressed in such ways as the volume of a refrigerator, temperature levels,

production output of a manufacturing facility, or lighting level per square foot. Load

management programs may either reduce electricity peak demand or shift demand from on peak

to non-peak periods.

Fuel substitution and load building programs share the common feature of increasing annual

consumption of either electricity or natural gas relative to what would have happened in the

absence of the program. This effect is accomplished in significantly different ways, by inducing

the choice of one fuel over another (fuel substitution), or by increasing sales of electricity, gas,

or electricity and gas (load building). Self generation refers to distributed generation (DG)

installed on the customer’s side of the electric utility meter, which serves some or all of the

customer's electric load, that otherwise would have been provided by the central electric grid.

In some cases, self generation products are applied in a combined heat and power manner, in

which case the heat produced by the self generation product is used on site to provide some or

all of the customer’s thermal needs. Self generation technologies include, but are not limited to,

photovoltaics, wind turbines, fuel cells, microturbines, small gas-fired turbines, and gas-fired

internal combustion engines.

Fuel substitution and load building programs were relatively new to demand-side management

in California in the late 1980s, born out of the convergence of several factors that translated into

average rates that substantially exceeded marginal costs. Proposals by utilities to implement

programs that increase sales had prompted the need for additional procedures for estimating

program cost effectiveness. These procedures maybe applicable in a new context. AB 970

amended the Public Utilities Code and provided the motivation to develop a cost-effectiveness

method that can be used on a common basis to evaluate all programs that will remove electric

load from the centralized grid, including energy efficiency, load control/demand-responsiveness

programs and self-generation. Hence, self-generation was also added to the list of demand side

management programs for cost-effectiveness evaluation. In some cases, self-generation

programs installed with incremental load are also included since the definition of self-generation

is not necessarily confined to projects that reduce electric load on the grid. For example,

suppose an industrial customer installs a new facility with a peak consumption of 1.5 MW, with

an integrated on-site 1.0 MW gas fired DG unit. The combined impact of the new facility is

load building since the new facility can draw up to 0.5 MW from the grid, even when the DG

unit is running. The proper characterization of each type of demand-side management program
3

is essential to ensure the proper treatment of inputs and the appropriate interpretation of costeffectiveness results.

Categorizing programs is important because in many cases the same specific device can be and

should be evaluated in more than one category. For example, the promotion of an electric heat

pump can and should be treated as part of a conservation program if the device is installed in

lieu of a less efficient electric resistance heater. If the incentive induces the installation of an

electric heat pump instead of gas space heating, however, the program needs to be considered

and evaluated as a fuel substitution program. Similarly, natural gas-fired self-generation, as well

as self-generation units using other non-renewable fossil fuels, must be treated as fuelsubstitution. In common with other types of fuel-substitution, any costs of gas transmission and

distribution, and environmental externalities, must be accounted for. In addition, costeffectiveness analyses of self-generation should account for utility interconnection costs.

Similarly, a thermal energy storage device should be treated as a load management program

when the predominant effect is to shift load. If the acceptance of a utility incentive by the

customer to, install the energy storage device is a decisive aspect of the customer's decision to

remain an electric utility customer (i.e., to reject or defer the option of installing a gas-fired

cogeneration system), then the predominant effect of the thermal energy storage device has been

to substitute electricity service for the natural gas service that would have occurred in the

absence of the program.

In addition to Fuel Substitution and Load Building Programs, recent utility program proposals

have included reference to "load retention," "sales retention," "market retention," or "customer

retention" programs. In most cases, the effect of such programs is identical to either a Fuel

Substitution or a Load Building program — sales of one fuel are increased relative to sales

without the program. A case may be made, however, for defining a separate category of program

called "load retention." One unambiguous example of a load retention program is the situation

where a program keeps a customer from relocating to another utility service area. However,

computationally the equations and guidelines included in this manual to accommodate Fuel

Substitution and Load Building programs can also handle this special situation as well.

Basic Methods

This manual identifies the cost and benefit components and cost-effectiveness calculation

procedures from four major perspectives: Participant, Ratepayer Impact Measure (RIM),

Program Administrator Cost (PAC), and Total Resource Cost (TRC). A fifth perspective, the

Societal, is treated as a variation on the Total Resource Cost test. The results of each perspective

can be expressed in a variety of ways, but in all cases it is necessary to calculate the net present

value of program impacts over the lifecycle of those impacts.

Table I summarizes the cost-effectiveness tests addressed in this manual. For each of the

perspectives, the table shows the appropriate means of expressing test results. The primary unit

of measurement refers to the way of expressing test results that are considered by the staffs of

the two Commissions as the most useful for summarizing and comparing demand-side

management (DSM) program cost-effectiveness. Secondary indicators of cost-effectiveness

represent supplemental means of expressing test results that are likely to be of particular value

for certain types of proceedings, reports, or programs.

This manual does not specify how the cost-effectiveness test results are to be displayed or the

level at which cost-effectiveness is to be calculated (e.g., groups of programs, individual

programs, and program elements for all or some programs). It is reasonable to expect different

levels and types of results for different regulatory proceedings or for different phases of the

process used to establish proposed program-funding levels. For example, for summary tables in
4

general rate case proceedings at the CPUC, the most appropriate tests may be the RIM lifecycle

revenue impact, Total Resource Cost, and Program Administrator Cost test results for programs

or groups of programs. The analysis and review of program proposals for the same proceeding

may include Participant test results and various additional indicators of cost-effectiveness from

all tests for each individual program element. In the case of cost-effectiveness evaluations

conducted in the context of integrated long-term resource planning activities, such detailed

examination of multiple indications of costs and benefits may be impractical.
5

Table I

Cost-Effectiveness Tests

Participant

Primary Secondary

Net present value (all participants)

Discounted payback (years)

Benefit-cost ratio

Net present value (average participant)

Ratepayer Impact Measure

Lifecycle revenue impact per Unit of

energy (kWh or therm) or demand

customer (kW)

Net present value

Lifecycle revenue impact per unit

Annual revenue impact (by year, per

kWh, kW, therm, or customer)

First-year revenue impact (per kWh, kW,

therm, or customer)

Benefit-cost ratio

Total Resource Cost

Net present value (NPV)

Benefit-cost ratio (BCR)

Levelized cost (cents or dollars per unit

of energy or demand)

Societal (NPV, BCR)

Program Administrator Cost

Net present value

Benefit-cost ratio

Levelized cost (cents or dollars per unit

of energy or demand)

Rather than identify the precise requirements for reporting cost-effectiveness results for all

types of proceedings or reports, the approach taken in this manual is to (a) specify the

components of benefits and costs for each of the major tests, (b) identify the equations to be

used to express the results in acceptable ways; and (c) indicate the relative value of the different

units of measurement by designating primary and secondary test results for each test.

It should be noted that for some types of demand-side management programs, meaningful costeffectiveness analyses cannot be performed using the tests in this manual. The following

guidelines are offered to clarify the appropriated "match" of different types of programs and

tests:

1. For generalized information programs (e.g., when customers are provided generic

information on means of reducing utility bills without the benefit of on-site evaluations

or customer billing data), cost-effectiveness tests are not expected because of the

extreme difficulty in establishing meaningful estimates of load impacts.

2. For any program where more than one fuel is affected, the preferred unit of

measurement for the RIM test is the lifecycle revenue impacts per customer, with gas

and electric components reported separately for each fuel type and for combined fuels.
6

3. For load building programs, only the RIM tests are expected to be applied. The Total

Resource Cost and Program Administrator Cost tests are intended to identify costeffectiveness relative to other resource options. It is inappropriate to consider increased

load as an alternative to other supply options.

4. Levelized costs may be appropriate as a supplementary indicator of cost per unit for

electric conservation and load management programs relative to generation options and

gas conservation programs relative to gas supply options, but the levelized cost test is

not applicable to fuel substitution programs (since they combine gas and electric effects)

or load building programs (which increase sales).

The delineation of the various means of expressing test results in Table 1 is not meant to

discourage the continued development of additional variations for expressing cost-effectiveness.

Of particular interest is the development of indicators of program cost effectiveness that can be

used to assess the appropriateness of program scope (i.e. level of funding) for General Rate

Case proceedings. Additional tests, if constructed from the net present worth in conformance

with the equations designated in this manual, could prove useful as a means of developing

methodologies that will address issues such as the optimal timing and scope of demand-side

management programs in the context of overall resource planning.

Balancing the Tests

The tests set forth in this manual are not intended to be used individually or in isolation. The

results of tests that measure efficiency, such as the Total Resource Cost Test, the Societal Test,

and the Program Administrator Cost Test, must be compared not only to each other but also to

the Ratepayer Impact Measure Test. This multi-perspective approach will require program

administrators and state agencies to consider tradeoffs between the various tests. Issues related

to the precise weighting of each test relative to other tests and to developing formulas for the

definitive balancing of perspectives are outside the scope of this manual. The manual, however,

does provide a brief description of the strengths and weaknesses of each test (Chapters 2, 3, 4,

and 5) to assist users in qualitatively weighing test results.

Limitations: Externality Values and Policy Rules

The list of externalities identified in Chapter 4, page 27, in the discussion on the Societal version

of the Total Resource Cost test is broad, illustrative and by no means exhaustive. Traditionally,

implementing agencies have independently determined the details such as the components of the

externalities, the externality values and the policy rules which specify the contexts in which the

externalities and the tests are used.

Externality Values

The values for the externalities have not been provided in the manual. There are separate studies

and methodologies to arrive at these values. There are also separate processes instituted by

implementing agencies before such values can be adopted formally.

Policy Rules

The appropriate choice of inputs and input components vary by program area and project. For

instance, low income programs are evaluated using a broader set of non-energy benefits that

have not been provided in detail in this manual. Implementing agencies traditionally have had

the discretion to use or to not use these inputs and/or benefits on a project- or program-specific

basis. The policy rules that specify the contexts in which it is appropriate to use the externalities,
7

their components, and tests mentioned in this manual are an integral part of any costeffectiveness evaluation. These policy rules are not a part of this manual.

To summarize, the manual provides the methodology and the cost-benefit calculations only. The

implementing agencies (such as the California Public Utilities Commission and the California

Energy Commission) have traditionally utilized open public processes to incorporate the diverse

views of stakeholders before adopting externality values and policy rules which are an integral

part of the cost-effectiveness evaluation.
8

Chapter 2

Participant Test

Definition

The Participants Test is the measure of the quantifiable benefits and costs to the customer due

to participation in a program. Since many customers do not base their decision to participate in

a program entirely on quantifiable variables, this test cannot be a complete measure of the

benefits and costs of a program to a customer.

Benefits and Costs

The benefits of participation in a demand-side program include the reduction in the customer's

utility bill(s), any incentive paid by the utility or other third parties, and any federal, state, or

local tax credit received. The reductions to the utility bill(s) should be calculated using the actual

retail rates that would have been charged for the energy service provided (electric demand or

energy or gas). Savings estimates should be based on gross savings, as opposed to net energy

savings1.

In the case of fuel substitution programs, benefits to the participant also include the avoided

capital and operating costs of the equipment/appliance not chosen. For load building programs,

participant benefits include an increase in productivity and/or service, which is presumably equal

to or greater than the productivity/ service without participating. The inclusion of these benefits

is not required for this test, but if they are included then the societal test should also be

performed.

The costs to a customer of program participation are all out-of-pocket expenses incurred as a

result of participating in a program, plus any increases in the customer's utility bill(s). The outof-pocket expenses include the cost of any equipment or materials purchased, including sales

tax and installation; any ongoing operation and maintenance costs; any removal costs (less

salvage value); and the value of the customer's time in arranging for the installation of the

measure, if significant.

 

1

 Gross energy savings are considered to be the savings in energy and demand seen by the participant at the

meter. These are the appropriate program impacts to calculate bill reductions for the Participant Test. Net

savings are assumed to be the savings that are attributable to the program. That is, net savings are gross savings

minus those changes in energy use and demand that would have happened even in the absence of the program.

For fuel substitution and load building programs, gross-to-net considerations account for the impacts that would

have occurred in the absence of the program.
9

How the Results can be Expressed

The results of this test can be expressed in four ways: through a net present value per average

participant, a net present value for the total program, a benefit-cost ratio or discounted payback.

The primary means of expressing test results is net present value for the total program;

discounted payback, benefit-cost ratio, and per participant net present value are secondary tests.

The discounted payback is the number of years it takes until the cumulative discounted benefits

equal or exceed the cumulative discounted costs. The shorter the discounted payback, the more

attractive or beneficial the program is to the participants. Although "payback period" is often

defined as undiscounted in the textbooks, a discounted payback period is used here to

approximate more closely the consumer's perception of future benefits and costs.2

Net present value (NPVp) gives the net dollar benefit of the program to an average participant or

to all participants discounted over some specified time period. A net present value above zero

indicates that the program is beneficial to the participants under this test.

The benefit-cost ratio (BCRp) is the ratio of the total benefits of a program to the total costs

discounted over some specified time period. The benefit-cost ratio gives a measure of a rough

rate of return for the program to the participants and is also an indication of risk. A benefit-cost

ratio above one indicates a beneficial program.

Strengths of the Participant Test

The Participants Test gives a good "first cut" of the benefit or desirability of the program to

customers. This information is especially useful for voluntary programs as an indication of

potential participation rates.

For programs that involve a utility incentive, the Participant Test can be used for program design

considerations such as the minimum incentive level, whether incentives are really needed to

induce participation, and whether changes in incentive levels will induce the desired amount of

participation.

These test results can be useful for program penetration analyses and developing program

participation goals, which will minimize adverse ratepayer impacts and maximize benefits.

For fuel substitution programs, the Participant Test can be used to determine whether program

participation (i.e. choosing one fuel over another) will be in the long-run best interest of the

customer. The primary means of establishing such assurances is the net present value, which

looks at the costs and benefits of the fuel choice over the life of the equipment.

Weaknesses of the Participant Test

None of the Participant Test results (discounted payback, net present value, or benefit-cost ratio)

accurately capture the complexities and diversity of customer decision-making processes for

demand-side management investments. Until or unless more is known about customer attitudes

and behavior, interpretations of Participant Test results continue to require considerable

 

2

 It should be noted that if a demand-side program is beneficial to its participants (NPVp >0 and BCRp >1.0)

using a particular discount rate, the program has an internal rate of return (IRR) of at least the value of the

discount rate.
10

judgment. Participant Test results play only a supportive role in any assessment of conservation

and load management programs as alternatives to supply projects.

Formulae

The following are the formulas for discounted payback, the net present value (NPVp) and the

benefit-cost ratio (BCRp) for the Participant Test.

NPVP = Bp - Cp

NPVavp = (Bp - Cp) / P

BCRp = Bp / Cp

DPp = Min j such that Bj > Cj

Where:

NPVp = Net present value to all participants

NPVavp = Net present value to the average participant

BCRp = Benefit-cost ratio to participants

DPp = Discounted payback in years

Bp = NPV of benefit to participants

Cp = NPV of costs to participants

Bj = Cumulative benefits to participants in year j

Cj = Cumulative costs to participants in year j

P = Number of program participants

J = First year in which cumulative benefits are cumulative costs.

d = Interest rate (discount)

The Benefit (Bp) and Cost (Cp) terms are further defined as follows: =

− +

+ +

=

N

t

t

t t t d

BR TC INC BP

1

1 (1 )

 + =

− +

+

N

t

t at at d

AB PA

1

1 (1 ) =

− +

+

=

N

t

t

t t d

PC BI C

1

1 (1 )

Where:

BRt = Bill reductions in year t

Bit = Bill increases in year t

TCt = Tax credits in year t

INCt = Incentives paid to the participant by the sponsoring utility in year t3

PCt = Participant costs in year t to include:

• Initial capital costs, including sales tax4

 

3

 Some difference of opinion exists as to what should be called an incentive. The term can be interpreted broadly

to include almost anything. Direct rebates, interest payment subsidies, and even energy audits can be called

incentives. Operationally, it is necessary to restrict the term to include only dollar benefits such as rebates or

rate incentives (monthly bill credits). Information and services such as audits are not considered incentives for

the purposes of these tests. If the incentive is to offset a specific participant cost, as in a rebate-type incentive,

the full customer cost (before the rebate must be included in the PCt term
11

• Ongoing operation and maintenance costs include fuel cost

• Removal costs, less salvage value

• Value of the customer's time in arranging for installation, if

significant

PACat = Participant avoided costs in year t for alternate fuel devices (costs of

devices not chosen)

Abat = Avoided bill from alternate fuel in year t

The first summation in the Bp equation should be used for conservation and load management

programs. For fuel substitution programs, both the first and second summations should be used

for Bp.

Note that in most cases, the customer bill impact terms (BRt, BIt, and ABat) are further

determined by costing period to reflect load impacts and/or rate schedules, which vary

substantially by time of day and season. The formulas for these variables are as follows: = = = × × + × × +

I

i

I

i

BRt EGit AC Eit Kit DGit AC Dit Kit OBRt 1 1( : ) ( : )

ABat = (Use BRt formula, but with rates and costing periods appropriate for the alternate

fuel utility) = = = × × − + × × − +

I

i

I

i

BIt EGit AC Eit Kit DGit AC Dit Kit OBIt 1 1( : ( 1)) ( : ( 1))

Where:

EGit = Reduction in gross energy use in costing period i in year t

DGit = Reduction in gross billing demand in costing period i in year t

AC:Eit = Rate charged for energy in costing period i in year t

AC:Dit = Rate charged for demand in costing period i in year t 

Kit = 1 when EGit or DGit is positive (a reduction) in costing period i in

year t, and zero otherwise

OBRt = Other bill reductions or avoided bill payments (e.g.,, customer charges,

standby rates).

OBIt = Other bill increases (i.e. customer charges, standby rates).

I = Number of periods of participant’s participation

In load management programs such as TOU rates and air-conditioning cycling, there are often

no direct customer hardware costs. However, attempts should be made to quantify indirect

costs customers may incur that enable them to take advantage of TOU rates and similar

programs.

 

4

 If money is borrowed by the customer to cover this cost, it may not be necessary to calculate the annual

mortgage and discount this amount if the present worth of the mortgage payments equals the initial cost. This

occurs when the discount rate used is equal to the interest rate of the mortgage. If the two rates differ (e.g., a

loan offered by the utility), then the stream of mortgage payments should be discounted by the discount rate

chosen.
12

If no customer hardware costs are expected or estimates of indirect costs and value of service

are unavailable, it may not be possible to calculate the benefit-cost ratio and discounted payback

period.
13

Chapter 3

The Ratepayer Impact Measure Test5

Definition

The Ratepayer Impact Measure (RIM) test measures what happens to customer bills or rates

due to changes in utility revenues and operating costs caused by the program. Rates will go

down if the change in revenues from the program is greater than the change in utility costs.

Conversely, rates or bills will go up if revenues collected after program implementation are less

than the total costs incurred by the utility in implementing the program. This test indicates the

direction and magnitude of the expected change in customer bills or rate levels.

Benefits and Costs

The benefits calculated in the RIM test are the savings from avoided supply costs. These

avoided costs include the reduction in transmission, distribution, generation, and capacity costs

for periods when load has been reduced and the increase in revenues for any periods in which

load has been increased. The avoided supply costs are a reduction in total costs or revenue

requirements and are included for both fuels for a fuel substitution program. The increase in

revenues are also included for both fuels for fuel substitution programs. Both the reductions in

supply costs and the revenue increases should be calculated using net energy savings.

The costs for this test are the program costs incurred by the utility, and/or other entities

incurring costs and creating or administering the program, the incentives paid to the

participant, decreased revenues for any periods in which load has been decreased and increased

supply costs for any periods when load has been increased. The utility program costs include

initial and annual costs, such as the cost of equipment, operation and maintenance, installation,

program administration, and customer dropout and removal of equipment (less salvage value).

The decreases in revenues and the increases in the supply costs should be calculated for both

fuels for fuel substitution programs using net savings.

How the Results can be Expressed

The results of this test can be presented in several forms: the lifecycle revenue impact (cents or

dollars) per kWh, kW, therm, or customer; annual or first-year revenue impacts (cents or dollars

per kWh, kW, therms, or customer); benefit-cost ratio; and net present value. The primary units

of measurement are the lifecycle revenue impact, expressed as the change in rates (cents per

kWh for electric energy, dollars per kW for electric capacity, cents per therm for natural gas)

and the net present value. Secondary test results are the lifecycle revenue impact per customer,

first-year and annual revenue impacts, and the benefit-cost ratio. LRIRIM values for programs

affecting electricity and gas should be calculated for each fuel individually (cents per kWh or

dollars per kW and cents per therm) and on a combined gas and electric basis (cents per

customer).

 

5

 The Ratepayer Impact Measure Test has previously been described under what was called the "Non-Participant

Test." The Non-Participant Test has also been called the "Impact on Rate Levels Test."
14

The lifecycle revenue impact (LRI) is the one-time change in rates or the bill change over the life

of the program needed to bring total revenues in line with revenue requirements over the life of

the program. The rate increase or decrease is expected to be put into effect in the first year of

the program. Any successive rate changes such as for cost escalation are made from there. The

first-year revenue impact (FRI) is the change in rates in the first year of the program or the bill

change needed to get total revenues to match revenue requirements only for that year. The

annual revenue impact (ARI) is the series of differences between revenues and revenue

requirements in each year of the program. This series shows the cumulative rate change or bill

change in a year needed to match revenues to revenue requirements. Thus, the ARIRIM for year

six per kWh is the estimate of the difference between present rates and the rate that would be in

effect in year six due to the program. For results expressed as lifecycle, annual, or first-year

revenue impacts, negative results indicate favorable effects on the bills of ratepayers or

reductions in rates. Positive test result values indicate adverse bill impacts or rate increases.

Net present value (NPVRIM) gives the discounted dollar net benefit of the program from the

perspective of rate levels or bills over some specified time period. A net present value above zero

indicates that the program will benefit (lower) rates and bills.

The benefit-cost ratio (BCR RIM) is the ratio of the total benefits of a program to the total costs

discounted over some specified time period. A benefit-cost ratio above one indicates that the

program will lower rates and bills.

Strengths of the Ratepayer Impact Measure (RIM)

Test

In contrast to most supply options, demand-side management programs cause a direct shift in

revenues. Under many conditions, revenues lost from DSM programs have to be made up by

ratepayers. The RIM test is the only test that reflects this revenue shift along with the other

costs and benefits associated with the program.

An additional strength of the RIM test is that the test can be used for all demand-side

management programs (conservation, load management, fuel substitution, and load building).

This makes the RIM test particularly useful for comparing impacts among demand-side

management options.

Some of the units of measurement for the RIM test are of greater value than others, depending

upon the purpose or type of evaluation. The lifecycle revenue impact per customer is the most

useful unit of measurement when comparing the merits of programs with highly variable scopes

(e.g.,, funding levels) and when analyzing a wide range of programs that include both electric

and natural gas impacts. Benefit-cost ratios can also be very useful for program design

evaluations to identify the most attractive programs or program elements.

If comparisons are being made between a program or group of conservation/load management

programs and a specific resource project, lifecycle cost per unit of energy and annual and firstyear net costs per unit of energy are the most useful way to express test results. Of course, this

requires developing lifecycle, annual, and first-year revenue impact estimates for the supply-side

project.

Weaknesses of the Ratepayer Impact Measure (RIM)

Test
15

Results of the RIM test are probably less certain than those of other tests because the test is

sensitive to the differences between long-term projections of marginal costs and long-term

projections of rates, two cost streams that are difficult to quantify with certainty.

RIM test results are also sensitive to assumptions regarding the financing of program costs.

Sensitivity analyses and interactive analyses that capture feedback effects between system

changes, rate design options, and alternative means of financing generation and non-generation

options can help overcome these limitations. However, these types of analyses may be difficult

to implement.

An additional caution must be exercised in using the RIM test to evaluate a fuel substitution

program with multiple end use efficiency options. For example, under conditions where

marginal costs are less than average costs, a program that promotes an inefficient appliance may

give a more favorable test result than a program that promotes an efficient appliance. Though

the results of the RIM test accurately reflect rate impacts, the implications for long-term

conservation efforts need to be considered.

Formulae: The formulae for the lifecycle revenue impact (LRI RIM)' net present value (NPV

RIM), benefit-cost ratio (BCR RIM)' the first-year revenue impacts and annual revenue impacts

are presented below:

LRIRIM = (CRIM - BRIM) / E

FRIRIM = (CRIM - BRIM) / E for t = I

ARIRIMt = FRIRIM for t = I

= (CRIMt - BRIMt )/Et for t=2, .............., N

NPVRIM = BRIM-CRIM

BCRRIM` = BRIM/CRIM where:

LRIRIM = Lifecycle revenue impact of the program per unit of energy (kWh or therm)

or demand (kW) (the one-time change in rates) or per customer (the change

in customer bills over the life of the program). (Note: An appropriate choice

of kWh, therm, kW, and customer should be made)

FRIRIM = First-year revenue impact of the program per unit of energy, demand, or per

customer.

ARIRIM = Stream of cumulative annual revenue impacts of the program per unit of

energy, demand, or per customer. (Note: The terms in the ARI formula are

not discounted; thus they are the nominal cumulative revenue impacts.

Discounted cumulative revenue impacts may be calculated and submitted if

they are indicated as such. Note also that the sum of the discounted stream of

cumulative revenue impacts does not equal the LRI RIM')

NPVRIM = Net present value levels

BCRRIM = Benefit-cost ratio for rate levels

BRIM = Benefits to rate levels or customer bills

CRIM = Costs to rate levels or customer bills

E = Discounted stream of system energy sales (kWh or therms) or demand sales

(kW) or first-year customers. (See Appendix D for a description of the

derivation and use of this term in the LRIRIM test.)
16

The BRIM and CRIM terms are further defined as follows: =

−

=

− +

+

+

+ N

t

tat N

t

t

t RIM d

UAC

d

UAC RG

B

t 1

1

1

1 (1 ) (1 ) =

−

=

− +

+

+

+ + +

N

t

t at N

t

t

t t t t RIM d

RL

d

UIC RL PRC INC C

1

1

1

1 (1 ) (1 ) =

− +

=

N

t

t

t d

E

E

1

1 (1 )

Where:

UACt = Utility avoided supply costs in year t

UICt = Utility increased supply costs in year t

RGt = Revenue gain from increased sales in year t

RLt = Revenue loss from reduced sales in year t

PRCt = Program Administrator program costs in year t

Et = System sales in kWh, kW or therms in year t or first year customers

UACat = Utility avoided supply costs for the alternate fuel in year t

Rlat = Revenue loss from avoided bill payments for alternate fuel in year t (i.e.,

device not chosen in a fuel substitution program)

For fuel substitution programs, the first term in the B RIM and C RIM equations represents the

sponsoring utility (electric or gas), and the second term represents the alternate utility. The RIM

test should be calculated separately for electric and gas and combined electric and gas.

The utility avoided cost terms (UACt, UICt, and UACat) are further determined by costing

period to reflect time-variant costs of supply:

( : ) ( : )

1 1

it it it

I

i

I

i

UCAt = ENit ×MC Eit ×Kit + DN ×MC D ×K

= =

UACat = (Use UACt formula, but with marginal costs and costing periods appropriate for

the alternate fuel utility.) = = × × − + × × −

I

i

I

i

UICt ENit MC Eit Kit DNit MC D Kit

1 1

( : ( 1)) ( : ( 1))

Where:

[Only terms not previously defined are included here.]

ENit = Reduction in net energy use in costing period i in year t

DNit = Reduction in net demand in costing period i in year t

MC:Eit = Marginal cost of energy in costing period i in year t

MC:Dit = Marginal cost of demand in costing period i in year t
17

The revenue impact terms (RGt, RLt, and RLat ) are parallel to the bill impact terms in the

Participant Test. The terms are calculated exactly the same way with the exception that the net

impacts are used rather than gross impacts. If a net-to-gross ratio is used to differentiate gross

savings from net savings, the revenue terms and the participant's bill terms will be related as

follows:

RGt = BIt * (net-to-gross ratio)

RLt = BRt * (net-to-gross ratio)

Rlat = Abat * (net-to-gross ratio)
18

Chapter 4

Total Resource Cost Test6

Definition

The Total Resource Cost Test measures the net costs of a demand-side management program as

a resource option based on the total costs of the program, including both the participants' and

the utility's costs.

The test is applicable to conservation, load management, and fuel substitution programs. For

fuel substitution programs, the test measures the net effect of the impacts from the fuel not

chosen versus the impacts from the fuel that is chosen as a result of the program. TRC test

results for fuel substitution programs should be viewed as a measure of the economic efficiency

implications of the total energy supply system (gas and electric).

A variant on the TRC test is the Societal Test. The Societal Test differs from the TRC test in

that it includes the effects of externalities (e.g.,, environmental, national security), excludes tax

credit benefits, and uses a different (societal) discount rate.

Benefits and Costs: This test represents the combination of the effects of a program on both the

customers participating and those not participating in a program. In a sense, it is the summation

of the benefit and cost terms in the Participant and the Ratepayer Impact Measure tests, where

the revenue (bill) change and the incentive terms intuitively cancel (except for the differences in

net and gross savings).

The benefits calculated in the Total Resource Cost Test are the avoided supply costs, the

reduction in transmission, distribution, generation, and capacity costs valued at marginal cost for

the periods when there is a load reduction. The avoided supply costs should be calculated using

net program savings, savings net of changes in energy use that would have happened in the

absence of the program. For fuel substitution programs, benefits include the avoided device

costs and avoided supply costs for the energy, using equipment not chosen by the program

participant.

The costs in this test are the program costs paid by both the utility and the participants plus the

increase in supply costs for the periods in which load is increased. Thus all equipment costs,

installation, operation and maintenance, cost of removal (less salvage value), and administration

costs, no matter who pays for them, are included in this test. Any tax credits are considered a

reduction to costs in this test. For fuel substitution programs, the costs also include the increase

in supply costs for the utility providing the fuel that is chosen as a result of the program.

 

6

 This test was previously called the All Ratepayers Test
19

How the Results Can be Expressed

The results of the Total Resource Cost Test can be expressed in several forms: as a net present

value, a benefit-cost ratio, or as a levelized cost. The net present value is the primary unit of

measurement for this test. Secondary means of expressing TRC test results are a benefit-cost

ratio and levelized costs. The Societal Test expressed in terms of net present value, a benefitcost ratio, or levelized costs is also considered a secondary means of expressing results.

Levelized costs as a unit of measurement are inapplicable for fuel substitution programs, since

these programs represent the net change of alternative fuels which are measured in different

physical units (e.g.,, kWh or therms). Levelized costs are also not applicable for load building

programs.

Net present value (NPVTRC) is the discounted value of the net benefits to this test over a

specified period of time. NPVTRC is a measure of the change in the total resource costs due to

the program. A net present value above zero indicates that the program is a less expensive

resource than the supply option upon which the marginal costs are based.

The benefit-cost ratio (BCRTRC) is the ratio of the discounted total benefits of the program to

the discounted total costs over some specified time period. It gives an indication of the rate of

return of this program to the utility and its ratepayers. A benefit-cost ratio above one indicates

that the program is beneficial to the utility and its ratepayers on a total resource cost basis.

The levelized cost is a measure of the total costs of the program in a form that is sometimes

used to estimate costs of utility-owned supply additions. It presents the total costs of the

program to the utility and its ratepayers on a per kilowatt, per kilowatt hour, or per therm basis

levelized over the life of the program.

The Societal Test is structurally similar to the Total Resource Cost Test. It goes beyond the

TRC test in that it attempts to quantify the change in the total resource costs to society as a

whole rather than to only the service territory (the utility and its ratepayers). In taking society's

perspective, the Societal Test utilizes essentially the same input variables as the TRC Test, but

they are defined with a broader societal point of view. More specifically, the Societal Test

differs from the TRC Test in at least one of five ways. First, the Societal Test may use higher

marginal costs than the TRC test if a utility faces marginal costs that are lower than other

utilities in the state or than its out-of-state suppliers. Marginal costs used in the Societal Test

would reflect the cost to society of the more expensive alternative resources. Second, tax credits

are treated as a transfer payment in the Societal Test, and thus are left out. Third, in the case of

capital expenditures, interest payments are considered a transfer payment since society actually

expends the resources in the first year. Therefore, capital costs enter the calculations in the year

in which they occur. Fourth, a societal discount rate should be used7. Finally, Marginal costs

used in the Societal Test would also contain externality costs of power generation not captured

by the market system. An illustrative and by no means exhaustive list of ‘externalities and their

components’ is given below (Refer to the Limitations section for elaboration.) These values are

also referred to as ‘adders’ designed to capture or internalize such externalities. The list of

potential adders would include for example:

1. The benefit of avoided environmental damage: The CPUC policy specifies two ‘adders’ to

internalize environmental externalities, one for electricity use and one for natural gas use.

Both are statewide average values. These adders are intended to help distinguish between

 

7 Many economists have pointed out that use of a market discount rate in social cost-benefit analysis

undervalues the interests of future generations. Yet if a market discount rate is not used, comparisons with

alternative investments are difficult to make.
20

cost-effective and non cost-effective energy-efficiency programs. They apply to an average

supply mix and would not be useful in distinguishing among competing supply options.

The CPUC electricity environmental adder is intended to account for the environmental

damage from air pollutant emissions from power plants. The CPUC-adopted adder is

intended to cover the human and material damage from sulfur oxides (SOX), nitrogen

oxides (NOX), volatile organic compounds (VOC, sometimes called reactive organic gases

or ROG), particulate matter at or below 10 micron diameter (PM10), and carbon. The adder

for natural gas is intended to account for air pollutant emissions from the direct combustion

of the gas. In the CPUC policy guidance, the adders are included in the tabulation of the

benefits of energy efficiency programs. They represent reduced environmental damage

from displaced electricity generation and avoided gas combustion. The environmental

damage is the result of the net change in pollutant emissions in the air basins, or regions, in

which there is an impact. This change is the result of direct changes in powerplant or

natural gas combustion emission resulting from the efficiency measures, and changes in

emissions from other sources, that result from those direct changes in emissions.

2. The benefit of avoided transmission and distribution costs – energy efficiency measures that

reduce the growth in peak demand would decrease the required rate of expansion to the

transmission and distribution network, eliminating costs of constructing and maintaining

new or upgraded lines.

3. The benefit of avoided generation costs – energy efficiency measures reduce consumption

and hence avoid the need for generation. This would include avoided energy costs, capacity

costs and T&D line

4. The benefit of increased system reliability: The reductions in demand and peak loads from

customers opting for self generation, provide reliability benefits to the distribution system in

the forms of:

a. Avoided costs of supply disruptions

b. Benefits to the economy of damage and control costs avoided by customers and

industries in the digital economy that need greater than 99.9 level of reliable electricity

service from the central grid

c. Marginally decreased System Operator’s costs to maintain a percentage reserve of

electricity supply above the instantaneous demand

d. Benefits to customers and the public of avoiding blackouts.

5. Non-energy benefits: Non-energy benefits might include a range of program-specific

benefits such as saved water in energy-efficient washing machines or self generation units,

reduced waste streams from an energy-efficient industrial process, etc.

6. Non-energy benefits for low income programs: The low income programs are social

programs which have a separate list of benefits included in what is known as the ‘low

income public purpose test’. This test and the sepcific benefits associated with this test are

outside the scope of this manual.

7. Benefits of fuel diversity include considerations of the risks of supply disruption, the effects

of price volatility, and the avoided costs of risk exposure and risk management.

Strengths of the Total Resource Cost Test

The primary strength of the Total Resource Cost (TRC) test is its scope. The test includes total

costs (participant plus program administrator) and also has the potential for capturing total

benefits (avoided supply costs plus, in the case of the societal test variation, externalities). To the
21

extent supply-side project evaluations also include total costs of generation and/or transmission,

the TRC test provides a useful basis for comparing demand- and supply-side options.

Since this test treats incentives paid to participants and revenue shifts as transfer payments

(from all ratepayers to participants through increased revenue requirements), the test results are

unaffected by the uncertainties of projected average rates, thus reducing the uncertainty of the

test results. Average rates and assumptions associated with how other options are financed

(analogous to the issue of incentives for DSM programs) are also excluded from most supplyside cost determinations, again making the TRC test useful for comparing demand-side and

supply-side options.

Weakness of the Total Resource Cost Test

The treatment of revenue shifts and incentive payments as transfer payments, identified

previously as a strength, can also be considered a weakness of the TRC test. While it is true that

most supply-side cost analyses do not include such financial issues, it can be argued that DSM

programs should include these effects since, in contrast to most supply options, DSM programs

do result in lost revenues.

In addition, the costs of the DSM "resource" in the TRC test are based on the total costs of the

program, including costs incurred by the participant. Supply-side resource options are typically

based only on the costs incurred by the power suppliers.

Finally, the TRC test cannot be applied meaningfully to load building programs, thereby

limiting the ability to use this test to compare the full range of demand-side management

options.

Formulas

The formulas for the net present value (NPVTRC)' the benefit-cost ratio (BCRTRC and levelized

costs are presented below:

NPVTRC = BTRC - CTRC

BCRTRC = BTRC /CTRC

LCTRC = LCRC / IMP

Where:

NPVTRC = Net present value of total costs of the resource

BCRTRC = Benefit-cost ratio of total costs of the resource

LCTRC = Levelized cost per unit of the total cost of the resource (cents per kWh for

conservation programs; dollars per kW for load management programs)

BTRC = Benefits of the program

CTRC = Costs of the program

LCRC = Total resource costs used for levelizing

IMP = Total discounted load impacts of the program

PCN = Net Participant Costs

The BTRC CTRC LCRC, and IMP terms are further defined as follows: = =

− − +

+

+

+

+

=

N

t Nt

t at att

t t d

UAC PAC

d

UAC TC BTRC

1 1

1 1 (1 ) (1 )
22

=

− +

+ +

=

N

t

t

t t t d

PRC PCN UIC CTRC

1

1 (1 ) =

− +

+ −

=

N

t

t

t t t d

PRC PCN TC LCRC

1

1 (1 )

1

1 1

(1 )

( ) ( ) −

= = +

= =

t n

t ni

it it

d

IMP EN or DN where I peak period

[All terms have been defined in previous chapters.]

The first summation in the BTRC equation should be used for conservation and load

management programs. For fuel substitution programs, both the first and second summations

should be used.
23

Chapter 5

Program Administrator Cost Test

Definition

The Program Administrator Cost Test measures the net costs of a demand-side management

program as a resource option based on the costs incurred by the program administrator

(including incentive costs) and excluding any net costs incurred by the participant. The benefits

are similar to the TRC benefits. Costs are defined more narrowly.

Benefits and Costs

The benefits for the Program Administrator Cost Test are the avoided supply costs of energy

and demand, the reduction in transmission, distribution, generation, and capacity valued at

marginal costs for the periods when there is a load reduction. The avoided supply costs should

be calculated using net program savings, savings net of changes in energy use that would have

happened in the absence of the program. For fuel substitution programs, benefits include the

avoided supply costs for the energy-using equipment not chosen by the program participant

only in the case of a combination utility where the utility provides both fuels.

The costs for the Program Administrator Cost Test are the program costs incurred by the

administrator, the incentives paid to the customers, and the increased supply costs for the

periods in which load is increased. Administrator program costs include initial and annual costs,

such as the cost of utility equipment, operation and maintenance, installation, program

administration, and customer dropout and removal of equipment (less salvage value). For fuel

substitution programs, costs include the increased supply costs for the energy-using equipment

chosen by the program participant only in the case of a combination utility, as above.

In this test, revenue shifts are viewed as a transfer payment between participants and all

ratepayers. Though a shift in revenue affects rates, it does not affect revenue requirements,

which are defined as the difference between the net marginal energy and capacity costs avoided

and program costs. Thus, if NPVpa > 0 and NPVRIM < 0, the administrator’s overall total

costs will decrease, although rates may increase because the sales base over which revenue

requirements are spread has decreased.

How the Results Can be Expressed

The results of this test can be expressed either as a net present value, benefit-cost ratio, or

levelized costs. The net present value is the primary test, and the benefit-cost ratio and levelized

cost are the secondary tests.

Net present value (NPVpa) is the benefit of the program minus the administrator's costs,

discounted over some specified period of time. A net present value above zero indicates that this

demand-side program would decrease costs to the administrator and the utility.

The benefit-cost ratio (BCRpa) is the ratio of the total discounted benefits of a program to the

total discounted costs for a specified time period. A benefit-cost ratio above one indicates that

the program would benefit the combined administrator and utility's total cost situation.
24

The levelized cost is a measure of the costs of the program to the administrator in a form that is

sometimes used to estimate costs of utility-owned supply additions. It presents the costs of the

program to the administrator and the utility on per kilowatt, per kilowatt-hour, or per therm basis

levelized over the life of the program.

Strengths of the Program Administrator Cost Test

As with the Total Resource Cost test, the Program Administrator Cost test treats revenue shifts

as transfer payments, meaning that test results are not complicated by the uncertainties

associated with long-term rate projections and associated rate design assumptions. In contrast to

the Total Resource Cost test, the Program Administrator Test includes only the portion of the

participant's equipment costs that is paid for by the administrator in the form of an incentive.

Therefore, for purposes of comparison, costs in the Program Administrator Cost Test are

defined similarly to those supply-side projects which also do not include direct customer costs.

Weaknesses of the Program Administrator Cost

Test

By defining device costs exclusively in terms of costs incurred by the administrator, the

Program Administrator Cost test results reflect only a portion of the full costs of the resource.

The Program Administrator Cost Test shares two limitations noted previously for the Total

Resource Cost test: (1) by treating revenue shifts as transfer payments, the rate impacts are not

captured, and (2) the test cannot be used to evaluate load building programs.

Formulas

The formulas for the net present value, the benefit-cost ratio and levelized cost are presented

below:

NPVpa = Bpa - Cpa

BCRpa = Bpa/Cpa

LCpa = LCpa/IMP

Where:

NPVpa Net present value of Program Administrator costs

BCRpa Benefit-cost ratio of Program Administrator costs

LCpa Levelized cost per unit of Program Administrator cost of the resource

Bpa Benefits of the program

Cpa Costs of the program

LCpc Total Program Administrator costs used for levelizing +

−

=

− +

+

+

=

N

t

tat N

t

t

t pa d

UAC

d

UAC B

1

1

1

1 (1 ) (1 ) =

− +

+ +

=

N

t

t

t t t pa d

PRC INC UIC C

1

1 (1 )
25

=

− +

+

=

N

t

t

t t d

PRC INC LCpc

1

1 (1 )

 [All variables are defined in previous chapters.]

The first summation in the Bpa equation should be used for conservation and load management

programs. For fuel substitution programs, both the first and second summations should be

used.
26

Appendix A

Inputs to Equations and

Documentation

A comprehensive review of procedures and sources for developing inputs is beyond the scope

of this manual. It would also be inappropriate to attempt a complete standardization of

techniques and procedures for developing inputs for such parameters as load impacts, marginal

costs, or average rates. Nevertheless, a series of guidelines can help to establish acceptable

procedures and improve the chances of obtaining reasonable levels of consistent and

meaningful cost-effectiveness results. The following "rules" should be viewed as appropriate

guidelines for developing the primary inputs for the cost-effectiveness equations contained in

this manual:

1. In the past, Marginal costs for electricity were based on production cost model simulations

that clearly identify key assumptions and characteristics of the existing generation system as

well as the timing and nature of any generation additions and/or power purchase agreements

in the future. With a deregulated market for wholesale electricity, marginal costs for electric

generation energy should be based on forecast market prices, which are derived from recent

transactions in California energy markets. Such transactions could include spot market

purchases as well as longer term bilateral contracts and the marginal costs should be

estimated based on components for energy as well as demand and/or capacity costs as is

typical for these contracts.

2. In the case of submittals in conjunction with a utility rate proceeding, average rates used in

DSM program cost-effectiveness evaluations should be based on proposed rates.

Otherwise, average rates should be based on current rate schedules. Evaluations based on

alternative rate designs are encouraged.

3. Time-differentiated inputs for electric marginal energy and capacity costs, average energy

rates, and demand charges, and electric load impacts should be used for (a) load

management programs, (b) any conservation program that involves a financial incentive to

the customer, and (c) any Fuel Substitution or Load Building program. Costing periods

used should include, at a minimum, summer and winter, on-, and off-peak; further

disaggregation is encouraged.

4. When program participation includes customers with different rate schedules, the average

rate inputs should represent an average weighted by the estimated mix of participation or

impacts. For General Rate Case proceedings it is likely that each major rate class within

each program will be considered as program elements requiring separate cost-effectiveness

analyses for each measure and each rate class within each program.

5. Program administration cost estimates used in program cost-effectiveness analyses should

exclude costs associated with the measurement and evaluation of program impacts unless

the costs are a necessary component to administer the program.

6. For DSM programs or program elements that reduce electricity and natural gas

consumption, costs and benefits from both fuels should be included.
27

7. The development and treatment of load impact estimates should distinguish between gross

(i.e., impacts expected from the installation of a particular device, measure, appliance) and

net (impacts adjusted to account for what would have happened anyway, and therefore not

attributable to the program). Load impacts for the Participants test should be based on

gross, whereas for all other tests the use of net is appropriate. Gross and net program

impact considerations should be applied to all types of demand-side management programs,

although in some instances there may be no difference between gross and net.

8. The use of sensitivity analysis, i.e. the calculation of cost-effectiveness test results using

alternative input assumptions, is encouraged, particularly for the following programs: new

programs, programs for which authorization to substantially change direction is being

sought (e.g.,, termination, significant expansion), major programs which show marginal

cost-effectiveness and/or particular sensitivity to highly uncertain input(s).

The use of many of these guidelines is illustrated with examples of program cost effectiveness

contained in Appendix B.
28

Appendix B

Summary of Equations and Glossary

of Symbols

Basic Equations

Participant Test

NPVP = BP - CP

NPVavp = (BP - CP) / P

BCRP = BP/CP

DPP = min j such that Bj > Cj

Ratepayer Impact Measure Test

LRIRIM = (CRIM - BRIM) / E

FRIRIM = (CRIM - BRIM) / E for t = 1

ARIRIMt = FRIRIM for t = 1

= (CRIMt- BRIMt )/Et for t=2,... ,N

NPVRIM = BRIM — CRIM

BCRRIM = BRIM /CRIM

Total Resource Cost Test

NPVTRC = BTRC - CTRC

BCRTRC = BTRC / CTRC

LCTRC = LCRC / IMP

Program Administrator Cost Test

NPVpa = Bpa - Cpa

BCRpa = Bpa / Cpa

LCpa = LCpa / IMP
29

Benefits and Costs

Participant Test = =

− − +

+

+

+

+ +

=

N

t Nt

t at att

t t t d

AB PAC

d

BR TC INC Bp

1 1

1 1 (1 ) (1 ) =

− +

+

N

t

t

t t d

PC BI Cp

1

1 (1 )

Ratepayer Impact Measure Test = =

− − +

+

+

+

=

N

t Nt

tatt

t t RIM d

UAC

d

UAC RG B

1 1

1 1 (1 ) (1 ) =

−

=

− +

+

+

+ + +

=

N

t

t at N

t

t

t t t t RIM d

RL

d

UIC RL PRC INC C

1

1

1

1 (1 ) (1 ) =

− +

=

N

t

t

t d

E

E

1

1 (1 )

Total Resource Cost Test = =

− − +

+

+

+

+

=

N

t Nt

t at att

t t TRC d

UAC PAC

d

UAC TC B

1 1

1 1 (1 ) (1 ) =

− +

+ +

=

N

t

t

t t t TRC d

PRC PCN UIC C

1

1 (1 ) =

− +

+ −

=

N

t

t

t t t TRC d

PRC PCN TC L

1

1 (1 )
30

1

1 1

(1 )

( ) ( ) −

= = +

= =

t n

t ni

it it

d

IMP EN or DN where I peak period

Program Administrator Cost Test = =

− − +

+

+

=

N

t Nt

tatt

t pa d

UAC

d

UAC B

1 1

1 1 (1 ) (1 ) =

− +

+ +

=

N

t

t

t t t pa d

PRC INC UIC C

1

1 (1 ) =

− +

+

=

N

t

t

t t d

PRC INC LCPA

1

1 (1 )

Glossary of Symbols

Abat = Avoided bill reductions on bill from alternate fuel in year t

AC:Dit = Rate charged for demand in costing period i in year t

AC:Eit = Rate charged for energy in costing period i in year t

ARIRIM = Stream of cumulative annual revenue impacts of the program per unit of

energy, demand, or per customer. Note that the terms in the ARI formula are

not discounted, thus they are the nominal cumulative revenue impacts.

Discounted cumulative revenue impacts may be calculated and submitted if

they are indicated as such. Note also that the sum of the discounted 

stream of cumulative revenue impacts does not equal the LRIRIM*

BCRp = Benefit-cost ratio to participants

BCRRIM = Benefit-cost ratio for rate levels

BCRTRC = Benefit-cost ratio of total costs of the resource

BCRpa = Benefit-cost ratio of program administrator and utility costs

BIt = Bill increases in year t

Bj = Cumulative benefits to participants in year j

Bp = Benefit to participants

BRIM = Benefits to rate levels or customer bills

BRt = Bill reductions in year t

BTRC = Benefits of the program

Bpa = Benefits of the program

Cj = Cumulative costs to participants in year i

Cp = Costs to participants

CRIM = Costs to rate levels or customer bills

CTRC = Costs of the program

Cpa = Costs of the program

D = discount rate

Dgit = Reduction in gross billing demand in costing period i in year t
31

Dnit = Reduction in net demand in costing period i in year t

DPp = Discounted payback in years

E = Discounted stream of system energy sales-(kWh or therms) or demand sales

(kW) or first-year customers

Egit = Reduction in gross energy use in costing period i in year t

Enit = Reduction in net energy use in costing period i in year t

Et = System sales in kWh, kW or therms in year t or first year customers

FRIRIM = First-year revenue impact of the program per unit of energy, demand, or per

customer.

IMP = Total discounted load impacts of the program

INCt = Incentives paid to the participant by the sponsoring utility in year t First year

in which cumulative benefits are > cumulative costs.

Kit = 1 when EGit or DGit is positive (a reduction) in costing period i in year t,

and zero otherwise

LCRC = Total resource costs used for levelizing

LCTRC = Levelized cost per unit of the total cost of the resource

LCPA = Total Program Administrator costs used for levelizing

Lcpa = Levelized cost per unit of program administrator cost of the resource

LRIRIM = Lifecycle revenue impact of the program per unit of energy (kWh or therm)

or demand (kW)-the one-time change in rates-or per customer-the change in

customer bills over the life of the program.

MC:Dit = Marginal cost of demand in costing period i in year t

MC:Eit = Marginal cost of energy in costing period i in year t

NPVavp = Net present value to the average participant

NPVP = Net present value to all participants

NPVRIM = Net present value levels

NPVTRC = Net present value of total costs of the resource

NPVpa = Net present value of program administrator costs

OBIt = Other bill increases (i.e., customer charges, standby rates)

OBRt = Other bill reductions or avoided bill payments (e.g., customer charges,

standby rates).

P = Number of program participants

PACat = Participant avoided costs in year t for alternate fuel devices
32

PCt = Participant costs in year t to include:

• Initial capital costs, including sales tax

• Ongoing operation and maintenance costs

• Removal costs, less salvage value

• Value of the customer's time in arranging for installation, if significant

PRCt = Program Administrator program costs in year t

PCN = Net Participant Costs

RGt = Revenue gain from increased sales in year t

RLat = Revenue loss from avoided bill payments for alternate fuel in year t 

(i.e., device not chosen in a fuel substitution program)

RLt = Revenue loss from reduced sales in year t

TCt = Tax credits in year t

UACat = Utility avoided supply costs for the alternate fuel in year t

UACt = Utility avoided supply costs in year t

PAt = Program Administrator costs in year t

UICt = Utility increased supply costs in year t
33

Appendix C.

Derivation of Rim Lifecycle Revenue

Impact Formula

Most of the formulas in the manual are either self-explanatory or are explained in the text. This

appendix provides additional explanation for a few specific areas where the algebra was

considered to be too cumbersome to include in the text.

Rate Impact Measure

The Ratepayer Impact Measure lifecycle revenue impact test (LRIRIM) is assumed to be the

one-time increase or decrease in rates that will re-equate the present valued stream of revenues

and stream of revenue requirements over the life of the program.

Rates are designed to equate long-term revenues with long-term costs or revenue requirements.

The implementation of a demand-side program can disrupt this equality by changing one of the

assumptions upon which it is based: the sales forecast. Demand-side programs by definition

change sales. This expected difference between the long-term revenues and revenue

requirements is calculated in the NPVRIM The amount which present valued revenues are

below present valued revenue requirements equals NPVRIM

The LRIRIM is the change in rates that creates a change in the revenue stream that, when

present valued, equals the NPVRIM* If the utility raises (or lowers) its rates in the base year by

the amount of the LRIRIM' revenues over the term of the program will again equal revenue

requirements. (The other assumed changes in rates, implied in the escalation of the rate values,

are considered to remain in effect.)

Thus, the formula for the LRIRIM is derived from the following equality where the present

value change in revenues due to the rate increase or decrease is set equal to the NPVRIM or the

revenue change caused by the program. =

− +

×

− =

N

t

t RIM t RIM d

LRI E NPV

1

1 (1 )

Since the LRIRIM term does not have a time subscript, it can be removed from the summation,

and the formula is then: =

− +

− = ×

N

t

t

t RIM RIM d

E NPV LRI

1

1 (1 )

Rearranging terms, we then get:=

− +

= −

N

t

t

t RIM RIM d

E

LRI NPV

1

1 (1 )
34

Thus, =

− +

=

N

t

t

t d

E

E

1

1 (1 )