ppt 10. Economics of Power Utilization - Large fonts.pptx

8/10/2019 ppt 10. Economics of Power Utilization - Large fonts.pptx

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EE 2802 Applied Electricity

Economics of Power Utilization


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Contents

1.Cost of electric power

2.Factors influencing costs & tariffs

3.Load curve

4.Tariff

5.Reduction of energy costs

6.Power factor correction


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1. Cost of Electric Power

Fixed cost

Running / Operating cost

All should be considered before fixing

the final kWh charges for the consumers


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Fixed Cost Operating Cost

Interest on capital

investment

Most of the fuel cost

Allowance for

depreciation

Small portion of

salaries & wages

Taxes & insurance Repair &

maintenance

Most of the salaries& wages

Small portion of the

fuel cost


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2. Factors Influencing Costs &

Tariffs

1. Demand

2. Diversity of demand

- Maximum demand of various

consumers not occur simultaneously- This results in lower costs of electricenergy


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3. Load Factor

Equipments are selecting for maximum

demand

Fully occupied or not, there are fixed

charges

Poor load factors -> charge per kWh high

To improve load factor -> accepting off-

2. Factors influencing Costs &

Tariffs


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4. Power Factor

Productive power - consumed in the

resistive loads

Non-productive power consumed in

inductive and capacitive loads

Low power factor -> greater non-productive

current

2. Factors influencing Costs &

Tariffs


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3. Load Curve

Following information can be obtained

Maximum load

Size of generator unit required

Daily operating schedule


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CEB Tariff - Domestic

Fixed Charge

Charge

(Rs/month)

Unit Charge

(Rs/kWh)

Up to 30 units 60.00 3.00

30 ~ 60 units 90.00 4.70

60 ~ 90 units 120.00 7.50

90 ~ 180 unitsunits

180.00 16.00

180 ~ 600

units

240.00 25.00


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CEB Tariff - Industry

FixedCharge

(Rs/month)

UnitCharge

(Rs/kWh)

DemandCharge

(Rs/kVA)

I-1 240.00 10.50

I-2 3000.00 9.30 675.00

I-3 3000.00 9.10 650.00

I-2 (TD) Peak 3000.00 24.60 650.00

Offpeak

8.40

I-3 (TD) Peal 3000.00 23.00 650.00

Off 8.00


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Example

A consumer has a maximum demand of10kW with a load factor of 60% and p.f.

0.8 lag. The traffic in force is Rs. 650.00

per kVA of max. demand per month, Rs.9.10 per kWh and Rs. 3000.00 as the fixed

charge.

a. Calculate saving in his monthly bill if heimproves p.f. to 0.9 lag

b. Show the effect of improving load factor

to 80% with the same max. demand and12


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5. Reduction of Energy Cost

How to reduce energy cost?

Monitor energy consumption

Choose energy efficient appliances andmethods

Reducing energy consumption makes;Reduce energy cost

Reduce pollution and make their

communities greener13


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6. Power Factor Correction

p.f. of all AC motors and transformers is high current14


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Disadvantages of low power factor

Line losses (I2R) is high

Large equipment are required

highcapital cost

Large voltage drop need extra

regulation equipmentLow efficiency

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Power factor improvement

Inject a leading current into the circuit1. Installation of static capacitors

2. Installation of synchronous motors

3. Phase advancers

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Documents

ppt 10. Economics of Power Utilization - Large fonts.pptx