Calculator 2

 

SOLACE RENEWABLE ENERGY PVT. LTD

Fax : (33) 2440 6503

(033) 2440 6503

e-mail– info@solacepower.com

 

 

 

 

 

 

 

 

SOLAR WATER HEATER PAY BACK CALCULATION CHART – DOMESTIC / Industrial

Note

You may change values where cells are filled with green colour.

 

 

 

 

Do not change values of cells with red letters.

 

 

 

 

 

 

You may copy values of green cells and red letters to the similar cells in (D) Payback Calculations.

(A). SYSTEM DETAILS

 

 

 

 

 

 

S.No.

Item details

Values

Unit

 

 

 

 

1

System capacity

500

LPD

 

 

 

 

2

System temperature

65

deg.C

 

 

 

 

3

System cost

70000

Rs.

 

 

 

 

4

Cold water temperature

25

deg.C

 

 

 

 

5

System working days

320

days

 

 

 

 

6

Heat generated per year

6400000

kcals

 

 

 

 

7

Heat generated per collector

400

kcals

 

 

 

 

8

No. of collectors reqd.

50

Nos.

 

 

 

 

(B). ALTERNATE FUEL REQUIREMENT DETAILS

 

 

 

 

 

9

Name of fuel

Electricity

HSD

FO

LDO

LNG

LPG

10

Calorific value (kcals/kg)

 

10100

10100

10100

10800

11000

11

Calorific value (kcals/litre)

10000

10000

10000

10600

10800

12

Calorific value (kacals/kWh)

860

 

13

Rate of fuel (Rs.per kg.)

 

41.00

22.00

22.00

33.00

37.00

14

Rate of fuel (Rs.per litre)

40.00

20.00

20.00

30.00

34.00

15

Rate of fuel (Rs.per kWh)

5.00

 

16

Inflation rate per annum

5%

17

Conversion efficiency

90%

90%

90%

90%

90%

90%

18

Combustion efficiency

99%

85%

85%

85%

70%

70%

19

Quantity of fuel required (kg.)

 

828

828

828

941

924

20

Quantity of fuel required (litre)

837

837

837

958

941

21

Quantity of fuel required (kWh)

8352

 

22

Total amount

image

41761

33464

16732

16732

28751

31981

(C). PAYBACK CALCULATION

 

 

 

 

 

 

YEAR

OUT FLOW

INFLOW

BALANCE

 

 

 

80%

Fuel cost savings

 

 

 

depreciation,

 

 

 

IT savings of

 

 

 

30%

 

 

 

1

70000

16800

41761

11439

Negative sign indicates reverse cash flow !

2

11439

4200

43849

-36611

3

-36611

0

46042

-82652

That is inflow of cash !

4

-82652

0

48344

-130996

 

 

 

5

-130996

0

50761

-181757

 

 

 

(D). CONCLUSION

 

 

 

 

 

 

1

Solar system pays back within two years from the date of installation.

16 months