1 | Building Technologies Program eere.energy.gov

Review of the Life-Cycle Cost and National 

Impacts Analyses

Katie Coughlin

Lawrence Berkeley National Laboratory

Low Voltage Dry-Type Distribution Transformers Negotiated 

Rulemaking Working Group Meeting

September 28, 2011
2 | Building Technologies Program eere.energy.gov

Steps in the Standards Rulemaking

Framework

Document

Preliminary

Analysis NOPR Final

Rule Date

Screening

Analysis

Engineering

Analysis

Energy Use and 

End-Use Load 

Characterization

Shipments

Analysis

National

Impact

Analysis

Markups for 

Equipment Price 

Determination

Life-Cycle

Cost and

Payback 

Period Analysis

Market & 

Technology 

Assessment

Preliminary 

Manufacturer 

Impact Analysis

Compliance 

Date
3 | Building Technologies Program eere.energy.gov

• Candidate Standard Levels (CSLs) and Efficiency Levels 

(ELs) are technically identical

– The name change refers to different stages of the rule-making 

process (preliminary vs NOPR)

– CSLs/ELs are defined for each individual design line

– We will use the term Efficiency Levels

• Trial Standard Levels are defined as a collection of CSLs for 

all the design lines within a product class

Note on Terminology

Analysis Acronym Depends on EL Depends on TSL

Engineering --- No No

Life Cycle Cost LCC Yes No

National Impacts NIA Yes Yes

Manufacturer Impacts MIA Yes Yes
4 | Building Technologies Program eere.energy.gov

LCC and PBP Analysis

A & B 

Parameter

Transformer 

Designs

A&B 

Selection

Markups & Total 

Installed Cost

LCC Transformer 

Loading

Electricity 

Cost & Prices

Electricity 

Growth & 

Price Trends

Discount 

Rates

Compliance 

Date, 

Lifetime

Transformer 

Design 

Selection

Simulate 

Load & Price

Discount Rate 

Selection

Annual Operating 

Costs 

Operating Costs 

over the Lifetime 

of the Transformer

Net Present Value 

of Lifetime 

Operating Cost

From: 

Engineering Analysis

From: 

Energy Use and Load 

Characterization 

Analysis
5 | Building Technologies Program eere.energy.gov

• 10,000 transformer installations for each LCC run

• Each installation has an owner and a number of 

characteristics that belong to the owner or installation

• These characteristics are the same for all efficiency levels

• The LCC loops through a series of calculations for each 

installation and each EL

– Pick an owner from the sample (4800 C&I buildings)

– Calculate statistical load simulation parameters

– Choose a transformer design

– Calculate the installation cost and annual operating costs

– Calculate the full LCC

• The effect of the efficiency level specification is to restrict the 

number of available designs

Mechanics of the LCC
6 | Building Technologies Program eere.energy.gov

• Capacity (representative unit)

• Total installed cost

• Test procedure efficiency rating

• Design features

– Core material

– Ratio of no-load to load losses

– Weight

• Commercial or industrial 

building

• Population weight

• Geographic location

• Seasonal marginal prices for 

electricity (kWh and kW)

• Evaluator (yes/no)

• Discount rate

• Monthly loss factor and peak 

responsibility factor

• Peak load factor

• Lifetime

• Installation constraints

Mechanics of the LCC (2)

Transformer Installation
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• The LCC does not assume test procedure loadings

• For transformers, efficiency depends on energy losses 

– No-load losses

• Parameterized by loss rate NL

• Occur whenever the transformer is energized

• Annual watt-hours = 8760*NL

– Load losses 

• Parameterized by loss rate LL = load loss at 100% load

• Vary with the square of the load on the transformer

• Load dependence is captured through the loss factor LSF

• A given efficiency can be achieved by a wide range of combinations of 

no-load and load loss rates

• The LCC accounts for time-varying electricity costs

– Operating Cost = ∑t

 transformer_loss(t)× electricity_cost(t)

– t is the time period index

– Time period is monthly for dry-type transformers in buildings

Energy Use and the LCC
8 | Building Technologies Program eere.energy.gov

Example: Cost-Efficiency data and

CSLs for DL7 (75 kVA, 1-phase)

$500 

$1,500 

$2,500 

$3,500 

$4,500 

$5,500 

$6,500 

$7,500 

$8,500 

$9,500 

97.80% 98.00% 98.20% 98.40% 98.60% 98.80% 99.00% 99.20% 99.40% 99.60%

Manufacturer Selling Price ($)

Efficiency at 35% Load, Temperature Corrected

M12_AlAl_bl_3leg

M12_CuAl_bl_3leg

M6_AlAl_bl_3leg

M6_AlAl_fm_3leg

M4_CuAl_fm_3leg

M3_AlAl_fm_3leg

M3_AlAl_slm_3leg

M3_AlAl_dgw_3leg

H0_AlAl_fm_3leg

H0_AlAl_slm_3leg

ZDMH_AlAl_dgw_3leg

H0_CuCu_fm_3leg

SA1_AlAl_dgw_5leg

SA1_CuCu_dgw_5leg

CSLs

CSL 0 CSL 1 CSL 2 CSL 3

NEMA Pr.

CSL 4 CSL 5 CSL 6 CSL 7
9 | Building Technologies Program eere.energy.gov

Transformer Design Selection

Example: DL7, efficiency level 5
10 | Building Technologies Program eere.energy.gov

Transformer Loading

• Loss factors are generated from load factor data and a statistical model

•The average RMS load can be adjusted by setting a sizing parameter (~25%)
11 | Building Technologies Program eere.energy.gov

Incremental Cost vs. Energy Savings

DL7 LCC Intermediate Results
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Example Results: LCC Savings 

(April 2011) for DL7

Box: 25% - 75% 

Whiskers: 5%-95%
13 | Building Technologies Program eere.energy.gov

• Detailed results for the representative units (Design Lines 6 

through 8) are extrapolated to full set of kVA ratings

• Use the 0.75 scaling law, with adjustments so that the 

efficiency vs. kVA curve is continuous at each representative 

unit

• The NIA generates national-level results

– Shipments are forecast shipments for each kVa

– Calculate aggregate dollar costs, benefits and energy savings

• National Impacts are dependent on the combination of ELs 

that are used to construct a draft TSL

• The NIA results posted Aug. 23 are for a set of draft TSLs 

which may be modified

Mechanics of the NIA
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Efficiency vs. kVa
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• Low Voltage Dry Type (Design Lines 6-8) draft TSLs

Summary of Cumulative National 

Energy Savings Impact (pub. Aug 23)

Design 

Line

Base 

(EPACT ‘05)

Draft Trial Standard Level

1 2 (NEMA 

Premium)

3 4 5 6

6 98.00 98.47 98.60 98.60 98.80 98.93 99.44

7 98.00 98.47 98.60 98.60 98.80 98.93 99.44

8 98.60 99.14 99.02 99.25 99.32 99.44 99.58

• Low Voltage Dry Type (Design Lines 6-8) National Impacts

Draft Trial Standard Level

Base 1 2 3 4 5 6

Transformer Shipments 2015-2044 (Billion KVA) 0.617 0.668 0.675 0.661 0.667 0.583 0.534

Equipment Cost ($Billions) 17.258 6.020 6.785 5.352 5.941 -5.449 -15.930

Operating Cost (Savings in ELs) ($Billions) 23.309 11.937 12.836 12.698 15.456 8.634 13.093

Cumulative Source Savings 2044 (Quads) 1.233 1.326 1.312 1.596 0.895 1.352

Net Present Value at 3% Discount Rate ($Billions) 17.957 19.620 18.051 21.397 3.185 -2.837

Net Present Value at 7% Discount Rate ($Billions) 6.880 7.558 6.779 7.956 -0.057 -4.024
16 | Building Technologies Program eere.energy.gov

Example Annual Savings and Cost 

Results (April meeting)

-$2.0

-$1.0

$0.0

$1.0

$2.0

$3.0

2016 2026 2036 2046 2056 2066 2076 2086 2096

Billions of 2010 Dollars

Liquid-Immersed - CSL3 

-$0.4

-$0.2

$0.0

$0.2

$0.4

$0.6

$0.8

$1.0

2016 2026 2036 2046 2056 2066 2076 2086 2096

Billions of 2010 Dollars

Dry-Type - CSL3 

-$2.0

-$1.0

$0.0

$1.0

$2.0

$3.0

$4.0

2016 2026 2036 2046 2056 2066 2076 2086 2096

Billions of 2010 Dollars

All Transformers - CSL3 

Operating Cost Savings Equipment Cost Net Savings
17 | Building Technologies Program eere.energy.gov

• National impacts depend on the choice of TSL

– Energy savings

– Net present economic value

– Emissions and social cost of carbon

– Manufacturer impacts

– Demand for new materials

• Certain TSLs are analyzed for most rule-making processes

– “Max Tech” required by law

– Maximum NPV (typically the minimum LCC)

– Maximum energy savings with non-negative LCC

• Additional TSLs are defined as appropriate

– Technology break-points

– Fill in gaps in the design spac

Analysis Results for draft TSLs
18 | Building Technologies Program eere.energy.gov

Supplementary slides from the April Public Meeting

Extra Slides
19 | Building Technologies Program eere.energy.gov

• The loss factor estimate is based on the rule-of-thumb

LSF = k × LF + (1-k) × LF2 with 0 ≤ k ≤ 1

• This equation is always true for some value of k between zero and 

one

• Use data to calculate a set of values (LF, LSF, k) and estimate a 

distribution for k

Dry-Type Transformers: Loss Factor 

Calculations

0%

5%

10%

15%

20%

25%

30%

35%

40%

45%

50%

0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9

parameter k

frequency

Low LF Medium LF High LF
20 | Building Technologies Program eere.energy.gov

• The monthly responsibility factor (RF) defines the contribution of 

transformer load losses to the building peak demand

• Expect the RF to be correlated to some degree with the load factor LF

– Low load factors imply temporally-variable loads and less predictable 

RF

– High load factors imply flat loads and higher, more predictable RF

• Use hourly building data to calculate a set of values (LF, RF) and 

define a distribution function that provides the probability of RF given 

a value for LF

Dry-type Transformers: 

Responsibility Factor Calculations

0.0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1.0

0.0 0.2 0.4 0.6 0.8 1.0

Load Factor

Responsibility Factor
21 | Building Technologies Program eere.energy.gov

• Energy price projections to 2035 based on EIA/AEO 2010 Reference Case

• AEO High Growth and Low Growth (AEO2010) cases run as a sensitivity

• Electricity price forecasts to 2075 are developed from the average rate of 

change over the period 2020-2035

Electricity Price Forecasts

80%

85%

90%

95%

100%

105%

110%

115%

120%

Real Price Relative to 2007

2005 2010 2015 2020 2025 2030 2035

Year

Reference Case High Growth Low Growth
22 | Building Technologies Program eere.energy.gov

• Energy price projections to 2035 based on EIA/AEO 2011 Reference Case

Electricity Price Forecasts

80%

85%

90%

95%

100%

105%

2005 2010 2015 2020 2025 2030 2035

Real Price Relative to 2008

Year

Reference Case High Growth Low Growth
23 | Building Technologies Program eere.energy.gov

Cost of Conserved Energy

(Undiscounted)

Defined as the incremental cost divided by energy savings (no discounting)

Compare to the marginal price of electricity for the installation
24 | Building Technologies Program eere.energy.gov

Survival and Retirement Functions

Mean Lifetime: 32 years 

Average: 32 Years

0.0%

0.5%

1.0%

1.5%

2.0%

2.5%

3.0%

3.5%

4.0%

0%

10%

20%

30%

40%

50%

60%

70%

80%

90%

100%

0 5 10 15 20 25 30 35 40 45 50 55 60

Transformer Retirement Rate (%)

Transformer Survival Rate (%)

Transformer Reliability

Transformer Retirements