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RM Reps Co.
16029 W 65th Place
Arvada, CO 80007

Fax: (888) 902-9020     Phone: (303) 274-8372

DOE Standards

The Low-Down on the New Department of Energy (DOE) Efficiency Requirements for Transformers

On October 12, 2007, the Department of Energy made a final ruling on new efficiency standards for single-phase and three-phase dry-type and liquid-filled transformers.  The new standards are mandatory and will go into effect January 1, 2010.

What was the history behind the ruling?
  • The Department of Energy (DOE) studied raising distribution transformer efficiency;
    • Reviewed options for technological feasibility, economical justification and energy savings
    • Initially six Trial Standard Levels were investigated (TSL1-TSL6), with two emerging as the likely standards
      • TSL2 – 1/3 of efficiency between NEMA TP-1 & TSL4
      • TSL4
  • FINAL RULING PUBLISHED OCTOBER 12, 2007
  • The Driver is to Reduce CO2 Emissions
What transformers were affected by the ruling (10 CFR Part 431)?
  • Single-phase:  A level between TSL-4 and TSL-5 was established for 10-833 kVA
  • Three-phase: A level between TSL-2 and TSL-3 was established for 45-2500 kVA
  • Ruling applies to all units manufactured 1-1-2010 and beyond
  • Does not affect distributor stock, only manufacturers
  • All transformers produced and imported to the U.S.
  • Does not apply to rebuilt transformers
  • Enforcement mechanisms are not fully defined
What are the new efficiency standards mandated for liquid-immersed single-phase and three-phase transformers?

SINGLE-PHASE

THREE-PHASE

kVA

Efficiency %

kVA

Efficiency %

10

98.62

15

98.36

15

98.76

30

98.62

25

98.91

45

98.76

37.5

99.01

75

98.91

50

99.08

112.5

99.01

75

99.17

150

99.08

100

99.23

225

99.17

167

99.25

300

99.23

250

99.32

500

99.25

333

99.36

750

99.32

500

99.42

1000

99.36

667

99.46

1500

99.42

833

99.49

2000

99.46

 

 

2500

99.49

Note:  All efficiency values are at 50 percent of nameplate-rated load, determined according to the DOE test procedure.  10 CFR Part 431, Sub-part K, Appendix A

What do these levels mean?

According to one expert, the new single-phase minimum efficiency is approximately equal to an evaluation formula of NL = $4.50 and LL = $1.00

For three-phase, the approximate evaluation is NL = $3.00 and LL=$1.00

These are only approximations.  There is not a direct translation between evaluation formulae and efficiency.  Compliance with minimum efficiency requirements is design specific.

How will the new efficiency standards impact manufacturing?

CPS will need to revise roughly 60% of its active catalog numbers before 1-1-2010 to meet requirements

The new efficiency levels will shift raw material usage that will tighten supply of the highest grades of core steel.  Significant additional capacity will not be on line until 2010. Therefore it is important to work with us early to determine design rules.

The DOE rules create no difficulties for CPS in terms of design and manufacturing, but material procurement will be increasingly challenging as the deadline approaches.

How will the new efficiency standards impact transformer design?
  • Transformer sizes and weights will change
  • Depends greatly on specific Customer designs & product lines, but in general large increase in core/coil weight
  • Decrease in fluid volume (core/coil displacement)
  • Overall weight increases slightly
  • Dimensions don’t appear to change dramatically
  • Transformer costs and prices will increase.  DOE estimates 6-12% cost increases, but this is based on static materials markets (Early 2006).  Actual price increases are a function of where customers are today, movements in the materials markets, and are design specific.
How is Cooper Power Systems positioning itself to address the upcoming changes?

  • Continue to maintain strong relationships with material suppliers
  • Continue to monitor all available technologies to meet minimum efficiency requirements
  • Undertake further studies to more precisely determine the overall impact of the ruling
When should DOE efficiency standards be written into specs?

Always!

In addition to the reduction of CO2 emissions from the new DOE efficiency standards, what more can be done to further reduce COemissions?

Specify Cooper Power’s Envirotemp® FR3™ Fluid for all of your liquid-filled transformers.   FR3™ fluid has a negative carbon footprint and absorbs CO2 during it’s production.  This vegetable-oil based fluid is composed from soy beans which breathes CO2 while the plants grow.

For information on the environmental comparisons between FR3™ Fluid, Mineral Oil, Silicone Oil and others, please refer to the Building for Environmental and Economic Sustainability (BEES) report

FR3™ Fluid could become the only dielectric fluid eligible for carbon credits in the future.

Together with the new DOE efficiency standards, Envirotemp® FR3™ Fluid positions you to:
  • Visibly demonstrate to your employees and consumers your environmental stewardship in a regulatory environment that demands GREEN Initiatives
  • Gain the total life cycle cost savings derived from a highly efficient, fire resistant, and longer lasting product
  • Obtain full cost recovery from your PUC for this leadership role
  • Adapt in an increasingly legislated and restrictive environment regarding green house emissions

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