1 | Building Technologies Program eere.energy.gov 

# Review of the Life

- Cycle Cost and National Impacts Analyses

Katie Coughlin Lawrence Berkeley National Laboratory

Liquid Immersed and Medium Voltage Dry

- Type Distribution Transformers Negotiated Rulemaking Working Group Meeting

September 15

- 16, 20112 | 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 Date3 | Building Technologies Program eere.energy.gov 

# LCC and PBP Analysis

A & B Parameter

Transformer Designs A&B Selection

Markups & T otal

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 Analysis4 | 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 either the owner or the transformer

• These characteristics are the same for all efficiency levels

• Owner characteristics include

– Geographic location

– Evaluator (yes/no); if yes an A & B value

– Electricity price

– Discount rate



# • Transformer characteristics

– Total installed cost

– Lifetime

– Peak load factor (relative to capacity)

– Load simulation

- > annual load losses

– Annual no

- load losses

• Transformer design (price, efficiency) selection may change with EL



# • The effect of the efficiency level specification is to restrict the number of available designs 

# Mechanics of the LCC5 | Building Technologies Program eere.energy.gov 

## • 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

• 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 hourly for utility

- owned transformers (liquid

- type)

– Time period is monthly for dry

- type transformers in buildings 

# Energy Use and the LCC6 | Building Technologies Program eere.energy.gov 

# Example: Cost

- Efficiency data and CSLs for DL1 (50 kVA, 1

- phase)

$1,500 $2,000 $2,500 $3,000 $3,500 $4,000 $4,500 $5,000

99.00% 99.10% 99.20% 99.30% 99.40% 99.50% 99.60% 99.70%Manufacturer Selling Price ($)

Efficiency at 50% Load, Temperature Corrected M5CuAl_sh M3AlAl_sh M3CuAl_sh M2AlAl_sh M2CuAl_sh ZDMHAlAl_sh ZDMHCuCu_sh SA1AlAl_sh SA1CuCu_sh CSLs CSL 0 CSL 1 CSL 2 CSL 3 CSL 4 CSL 5 CSL 67 | Building Technologies Program eere.energy.gov 

# LCC Transformer Design Selection

Illustrative Example: Sampled designs, Design Line 1, EL5

$0.00 $500.00 $1,000.00 $1,500.00 $2,000.00 $2,500.00 $3,000.00 $3,500.00 $4,000.00

99.00% 99.10% 99.20% 99.30% 99.40% 99.50% 99.60% Design Data Basecase CSLs CSL 58 | Building Technologies Program eere.energy.gov 

# Another View of Selected Designs

Example: Design Line 1, Efficiency Level 1

0 100 200 300 400 500 600 700 800 900 1000

0 50 100 150 200 250**Load Losses (watts)**



### No Load Losses (watts) 

### Design Load Losses (LL) vs No

**- Load Losses (NL)**  at rated load

Available Designs Selected Designs, Base Selected Designs, Standard Compliance



### Compliant Non

- compliant



## Residential Buildings9 | Building Technologies Program eere.energy.gov 

# Example Results: LCC Savings (April 2011)

Box: 25%

- 75% Whiskers: 5%

- 95% - 2000 - 1000 0 1000 2000 3000 4000

CSL 1 CSL 2 CSL 3 CSL 4 CSL 5 CSL 6Average LCC Savings ($)

Efficiency Level Design Line 1: Liquid

- immersed, 50 kVA , 1 Phase, 125 kVA BIL Average LCC Savings

median average

- 4000 - 3000 - 2000 - 1000 0 1000 2000 3000 4000

CSL 1 CSL 2 CSL 3 CSL 4 CSL 5 CSL 6 CSL 7Average LCC Savings ($)

Efficiency Level Design Line 7: Dry

- type, 75 kVA , 3 Phase, 10 kVA BIL Average LCC Savings

median average10 | Building Technologies Program eere.energy.gov 

# • Detailed results for 13 Design Lines are extrapolated to full set of equipment 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 for each equipment class (LVDT, MVDT, LI)

– 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

• Further downstream analyses (e.g. emissions impacts) also depend on the details TSL 

# Mechanics of the NIA11 | Building Technologies Program eere.energy.gov 

# Example: Efficiency vs. kVA

**Rep Unit Rep Unit** 

0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1

97.00 97.50 98.00 98.50 99.00 99.50 100.00

10 100 1000Efficiency (%)

kVA 

## Medium

- Voltage Dry

- Type, 96

- 150 kV BIL, 3

- Phase

Base

1

2
3

4

512 | Building Technologies Program eere.energy.gov Design

Line Base (2007 FR) Draft Trial Standard Level

1 2 3 4 5

1 99.08 99.16 99.22 99.25 99.31 99.50
2 98.91 99.00 99.07 99.11 99.18 99.46
3 99.42 99.51 99.54 99.57 99.61 99.73
4 99.08 99.16 99.22 99.25 99.31 99.60
5 99.42 99.51 99.54 99.57 99.61 99.69 

# Draft TSLs posted August 23 2011

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 Design

Line Base (2007 FR) Draft Trial Standard Level

1 2 3 4 5

9 98.82 98.99 99.12 99.28 99.38 99.59
10 99.22 99.40 99.50 99.53 99.60 99.67
11 98.67 98.81 98.94 99.06 99.13 99.50
12 99.12 99.30 99.39 99.46 99.53 99.65
13A 98.63 98.76 98.85 98.92 99.10 99.48
13B 99.15 99.31 99.38 99.43 99.49 99.5813 | 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 2096Billions 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 2096Billions 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 2096Billions of 2010 Dollars **All Transformers**

**- CSL3** 

Operating Cost Savings Equipment Cost Net Savings14 | Building Technologies Program eere.energy.gov 

# • Example: All liquid immersed transformers (Design Lines 1

- 5) 

# Summary of Cumulative National Energy Savings Impact (Aug 23)

Draft Trial Standard Level

Base 1 2 3 4 5 

### Transformer Shipments 2015

- 2044 (Billion KVA) 1.95 1.91 1.89 1.89 1.89 1.77
Equipment Cost ($Billions) 63.08

- 7.47

- 10.08

- 9.44

- 10.61

- 33.85 Operating Cost (Savings in ELs) ($Billions) 83.72 11.20 16.16 18.07 22.65 35.25 Cumulative Source Savings 2044 (Quads) 0.691 1.01 1.13 1.44 2.25 Net Present Value at 3% Discount Rate ($Billions) 3.73 6.08 8.63 12.04 1.40 Net Present Value at 7% Discount Rate ($Billions)

- 0.164 0.10 1.00 1.741

- 6.5115 | Building Technologies Program eere.energy.gov 

# • Changes to the definition of efficiency levels used in the LCC, or draft TSLs required for national impacts analyses, result in changes to the LCC and NIA results

• The input data and methods do not change

• Given a set of criteria for specifying draft TSLs, results can be provided to the committee as needed

– For example, minimum LCC, maximum energy savings, technology criteria



# • Suggestions on how to summarize the data are welcome 

# Analysis Results16 | Building Technologies Program eere.energy.gov 

# Liquid

- immersed Transformers: Price

- Load Correlation

• Hourly production price is correlated with the hourly system load

– Scatter plot of the hourly price (vertical axis) and hourly load (horizontal axis)

– Bin the data according to ranges of the load (stripes)

– Within each bin, price = average value + random increment

• Regional system load data define how many hours per year the load is in each bin

0 50 100 150 200 250

0 20000 40000 60000 80000 100000 120000 140000 160000Lambda $/MWh

Load MWh17 | Building Technologies Program eere.energy.gov 

## • The hourly transformer load is correlated with the hourly system load 

# Liquid

- immersed Transformers: System Load

– Transformer Load Correlation

1 3 5 7 9

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15Individual Load Bin

Aggregate Load Bin

0.000

- 0.005 0.005

- 0.010 0.010

- 0.015 0.015

- 0.020 1 3 5 7 9

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15Individual Load Bin

Aggregate Load Bin

0.000

- 0.005 0.005

- 0.010 0.010

- 0.015 0.015

- 0.020 0.020

- 0.025



## Residential Buildings Commercial Buildings18 | Building Technologies Program eere.energy.gov 

# • The loss factor estimate is based on the rule

- of

- thumb LSF = k × LF + (1

- k) × LF 2 

# 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 kfrequency Low LF Medium LF High LF19 | 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 FactorResponsibility Factor20 | Building Technologies Program eere.energy.gov 

# • The Department uses data to develop estimates of A and B values for transformer owners

• The A and B data capture current market purchase decision criteria

• A = NPV of no

- load losses

• B = NPV of load losses 

# Customer Choice Model (2) A and B Values

• Liquid

- immersed

• Data from previous analysis, supplemented by recent utility purchase bids

• Data cluster around two values of the ratio B:A



# • Dry

- type

• Derive A and B values from marginal electricity prices for commercial and industrial customers (ref. IEEE PC57.12.33/D8 Draft Guide for Distribution Transformer Loss Evaluation) y = 0.23x + 0.00 R2 = 0.91 y = 0.45x + 0.02 R2 = 0.61

0 1 2 3 4 5

0 2 4 6 8 10 12 14Load Losses (B) $/W ( 2010$)

No

- load Losses (A) $/W (2010$) Line 1
Line 2 Linear (Line 1) Linear (Line 2) Distributions of B Parameters versus A Parameters for Liquid

- Immersed Transformers21 | 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%

2005 2010 2015 2020 2025 2030 2035Real Price Relative to 2007



# Year Reference Case High Growth Low Growth22 | 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 2035Real Price Relative to 2008

Year Reference Case High Growth Low Growth23 | 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 60Transformer Retirement Rate (%)Transformer Survival Rate (%) 

### Transformer Reliability Transformer Retirements