elecsys_purchtransformer

7/29/2019 ElecSys_PurchTransformer

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Electrical Systems: Purchase Transformer

Transformers reduce voltage. Most utilities offer primary rates for customers who ownthe transformer at the electrical service. The primary rate typically offers a discount overthe secondary rate for customers where the utility owns the transformer. In our

experience, it usually becomes cost effective for a customer to purchase and maintain atransformer when the customers average electrical demand is about 1,000 kW or more.

In general transformers cost about $10 per kVA, plus wiring, disconnects and controls.Two quotes are shown below:

Your utility has quoted a price of $30,000 to purchase the two 1,500 kVA transformers.Since your transformers and all switch gear and wiring is in place, we estimate that yourcost would be about $30,000.

A new 1500 kVa, 12.47kV/480/277 volt transformer could be purchased today for about$15,000. Figure a day with a three man crew to install at about $25/man-hour (includestruck).

Examples follow:

AR 4554: PURCHASE TRANSFORMERS AND SWITCH TO PRIMARY RATE

Annual Savings Project Simple

Resource CO2 (lb) Dollars Cost Payback

Electric Fees $13,000

Maintenance -$1000Net $12,000 $15,000 15 months

AnalysisCurrently, your electric utility owns and maintains your transformers for your electricoperation. Your electric rate schedule depends on who owns and maintains thetransformers. If you were to purchase and maintain the transformers, you would movefrom a "Secondary" to a "Primary" service rate and save about $13,000 per year fromlower utility bills.

Recommendation

We recommend that you contact your utility and inquire about purchasing thetransformers. In addition, we recommend that you contact a heavy equipment contractorto find out how much a maintenance contract for the transformers would cost. You couldthen refine our estimate of savings and make better decision about purchasing thetransformers.


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Estimated SavingsUsing last year's electricity consumption data (and assuming a 85% power factor) andpublished rate schedules for primary and secondary service, we estimate that your annualelectricity bill would be about $13,000 per year less if you owned the transformers.Assuming that a maintenance contract could be purchased for $1,000 per year, annual

savings would be about $12,000 per year.

Date Days

Consumption

(kWh/period)

Consumption

(kWh/day)

BilledDemand (kW)

LoadFacto

r

Cost($/period

) Power Factor

Cost(calculated,primary

rate) Savings

1/1/97 31 345,440 11,143 792.0 0.59 $19,060 85% $ 18,536 $524

2/1/97 31 307,040 9,905 800.0 0.52 $18,353 85% $ 17,436 $918

3/1/97 28 347,360 12,406 960.0 0.54 $21,465 85% $ 20,485 $980

4/1/97 31 407,680 13,151 960.0 0.57 $22,751 85% $ 21,684 $1,068

5/1/97 30 454,080 15,136 1024.0 0.62 $24,642 85% $ 23,505 $1,137

6/1/97 31 506,400 16,335 1136.0 0.60 $27,334 85% $ 26,118 $1,2157/1/97 30 560,000 18,667 1152.0 0.68 $29,083 85% $ 27,409 $1,674

8/1/97 31 489,440 15,788 1104.0 0.60 $26,855 85% $ 25,576 $1,278

9/1/97 31 459,200 14,813 1040.0 0.59 $25,288 85% $ 24,061 $1,227

10/1/97 30 411,520 13,717 1040.0 0.55 $24,239 85% $ 23,090 $1,149

11/1/97 31 400,160 12,908 880.0 0.61 $21,737 85% $ 20,611 $1,127

12/1/97 30 308,640 10,288 976.0 0.44 $21,074 85% $ 20,094 $980

Tot/Avg 365 4,996,960 13,690 988.7 0.58$281,88

1Total

savings ------> $13,277

Estimated Implementation Cost

We estimate that your transformer capacity is about 1,500 kVA. In general transformerscost about $10 per kVA, plus wiring, disconnects and controls. Since your transformersand all switchgear and wiring is in place, we estimate that your cost would be about$15,000.

Estimated Simple PaybackSimple Payback = $15,000 cost / $12,000 /yr savings x 12 mo/yr = 15 months

AR 3354: CONSIDER PURCHASING ELECTRIC TRANSFORMERS

Annual Savings Project Simple

Resource CO2 (lb) Dollars Cost Payback Electric Fees $18,000 $30,000 20 months

AnalysisCurrently, your electric utility owns and maintains the two transformers for your electricoperation. Your electric rate schedule depends on who owns and maintains thetransformers. If you were to purchase and maintain the transformers, you would move


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from a "Secondary" to a "Primary" service rate and save about $19,000 per year fromlower utility bills.

RecommendationWe recommend that you contact your utility and inquire about purchasing the

transformers. In addition, we recommend that you contact a heavy equipment contractorto find out how much a maintenance contract for the transformers would cost. You couldthen refine our estimate of savings and make better decision about purchasing thetransformers.Estimated SavingsUsing last year's electricity consumption data (and assuming a 90% power factor) andpublished rate schedules for primary and secondary service, we estimate that your annualelectricity bill would be about $19,000 per year less if you owned the transformers.Assuming that a maintenance contract could be purchased for $1,000 per year, annualsavings would be about $18,000 per year.

Estimated Implementation CostAccording to management, your utility has quoted a price of $30,000 to purchase the two1,500 kVA transformers. In general transformers cost about $10 per kVA, plus wiring,disconnects and controls. Since your transformers and all switch gear and wiring is inplace, we estimate that your cost would be about $30,000.

Estimated Simple PaybackSimple Payback = $30,000 cost / $18,000 /yr savings x 12 mo/yr = 20 months

AR 5: CONSIDER PURCHASING ELECTRIC TRANSFORMERS

Present Recommended Annual Savings

Elec. Costs $222,017 /yr $213,017 /yr $9,000 /yr Maintenance 0$ $1,000 /yr -$1,000 /yr Net 0 $8,000 /yr

Implementation Cost $17,000Simple Payback 26 months

AnalysisCurrently, your electric utility owns and maintains the two transformers for your electricoperation. Your electric rate schedule depends on who owns and maintains the

transformers. If you were to purchase and maintain the transformers, you would movefrom a "Secondary" to a "Primary" service rate and save about $9,000 per year fromlower utility bills.

RecommendationWe recommend that you contact your utility and inquire about purchasing thetransformers. In addition, we recommend that you contact a heavy equipment contractorto find out how much a maintenance contract for the transformers would cost. You could


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then refine our estimate of savings and make better decision about purchasing thetransformers.Estimated SavingsUsing last year's electricity consumption data (and assuming a 90% power factor) and

published rate schedules for primary and secondary service, we estimate that your annualelectricity bill would be about $9,000 per year less if you owned the transformers.Assuming that a maintenance contract could be purchased for $1,000 per year, annualsavings would be about $8,000 per year.

Estimated Implementation CostYour peak demand during the last year was 928 kW. Assuming some room for growth,and 25% additional capacity for insurance, we estimate that you need about 1,500 kVA oftransformer capacity. The cost of tranformers varies widely. The current transformersmight be purchased directly from the utility or new ones could be purchased fromindependent suppliers. In general transformers cost about $10 per kVA, plus $2,000 for

wiring, disconnects and controls. Thus, we estimate the cost of purchasing thetransformers would be about:

[1,500 kVA x $10 /kVA] + $2,000 = $17,000.

Estimated Simple PaybackSP = $17,000 (first cost) / $8,000 /yr (savings) x 12 mo/yr = 26 months

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