1 | Building Technologies Program eere.energy.gov The Parker Ranch installation in Hawaii 

# BUILDING TECHNOLOGIES PROGRAM

Distribution Transformers Energy Conservation Program Preliminary Analysis James Raba

U.S. Department of Energy Energy Efficiency & Renewable Energy Jim.Raba@ee.doe.gov



# October 12, 20112 | Building Technologies Program eere.energy.gov 

# • Transformer Loading

• Transformer Lifetime

• Transformer Peak Load Factor

• Changes to LCC Subgroups

• Equipment Price Trends

• Electricity Prices

• Limited Design Selection Due to a Fixed Efficiency 

# LV LCC Adjustments3 | Building Technologies Program eere.energy.gov 

# RMS Load for DL 7

0 100 200 300 400 500 600

4.2% 11.5% 18.8% 26.2% 33.5% 40.1%Frequency RMSLoading (annual) Forecast values

Trials 10,000

Mean 22.1%

Median 22.2%

Mode 27.6%
Standard Deviation 6.6%

Variance 0.4%
Skewness

- 0.0845

Kurtosis 2.65 Coeff. of Variability 0.2959

Minimum 2.8%

Maximum 41.9% Range Width 39.1%
Mean Std. Error 0.1%4 | Building Technologies Program eere.energy.gov 

# Service Lifetime

Average transformer lifetime is 32 years

Reference: ORNL

- 6847 Determination Analysis of Energy
Conservation Standards for Distribution Transformers 

# Each transformer in the LCC simulation has a unique lifetime
Failure rates: 0.5% per year from the first year of installation, due to lightning and
other random causes Additional 0.5% per year due to corrosion, starting in year 15 

# The failure rates are used to create a survival function, assuming a standard Weibull shape5 | Building Technologies Program eere.energy.gov 

# Lifetime: DL 7

0 100 200 300 400 500 600 700

2 13 25 37 49 59Frequency life Forecast values

Trials 10,000

Mean 32

Median 33

Mode 35
Standard Deviation 12

Variance 138
Skewness

- 0.3293

Kurtosis 2.78 Coeff. of Variability 0.3686

Minimum 1

Maximum 60 Range Width 59
Mean Std. Error 06 | Building Technologies Program eere.energy.gov 

# • Transformer peak load is a flat distribution ranging from 70 to 90% of nameplate 

# Peak Load Factor7 | Building Technologies Program eere.energy.gov 

# • Would like to the explore the possibility of adding Datacenters as a subgroup to the LCC analysis

– Would need data on:

• Any material limitations

• Any manufacturing techniques limitations

• Load Factor

• Average lifetime



# • To implement this subgroup we would need data.

• Can we use the same price, efficiency data that is currently
used for DL8? 

# Possible LCC Subgroup: Datacenters8 | Building Technologies Program eere.energy.gov 

# • Estimates the impacts of increasing or decreasing transformer prices at a national level over time.

• These are calculated as sensitivities in the NIA

– The default case assumes flat prices over time

– The low price case is modeled on historical price index from

1967 to 2010.

– The high price case is modeled on the historical price index from

1991 to 2010. 

# Equipment Price Trends9 | Building Technologies Program eere.energy.gov 

# Equipment Price Trends (cont.)

0.600 0.700 0.800 0.900 1.000 1.100 1.200 1.300

1960 1970 1980 1990 2000 2010 2020 2030 2040 2050Price Factor Index (2010=1)

Year



### Low Price Scenario: PPI Exponential Fit (1967 to 2010) Default Scenario: Constant Price Index

High Price Scenario: PPI Exponential Fit (1991 to 2010) Deflated PPI (2010=1)10 | Building Technologies Program eere.energy.gov 

# • Electricity prices were re

- scaled using AEO Price Trends 

# Electricity Prices

80% 85% 90% 95% 100% 105%

2005 2010 2015 2020 2025 2030 2035Real Price Relative to 2008

Year Reference Case High Growth Low Growth11 | Building Technologies Program eere.energy.gov 

# • Fixed efficiency ratings only impact the selection of transformers with a diversity of A and B in the most extreme

cases.

• Here A and B are calculated from customer marginal price for

energy

• The following slides illustrate the designs selected in the LCC
for DL7. 

# Limited Design Selection Due to a Fixed Efficiency12 | Building Technologies Program eere.energy.gov 

# DL 7: EL 1

0 500 1,000 1,500 2,000 2,500 3,000 3,500

0 50 100 150 200 250 300 350 400 450 500Load 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, Standard13 | Building Technologies Program eere.energy.gov 

# DL 7: EL 3

0 500 1,000 1,500 2,000 2,500 3,000 3,500

0 50 100 150 200 250 300 350 400 450 500Load 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, Standard14 | Building Technologies Program eere.energy.gov 

# DL 7: EL 7

0 500 1,000 1,500 2,000 2,500 3,000 3,500

0 50 100 150 200 250 300 350 400 450 500Load 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, Standard15 | Building Technologies Program eere.energy.gov 

# Thank you