Calculator 1

 

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

100

LPD

 

 

 

 

2

System temperature

65

deg.C

 

 

 

 

3

System cost

17000

Rs.

 

 

 

 

4

Cold water temperature

25

deg.C

 

 

 

 

5

System working days

320

days

 

 

 

 

6

Heat generated per year

1280000

kcals

 

 

 

 

7

Heat generated per Tube

400

kcals

 

 

 

 

8

No. of Tubes reqd.

10

Nos.

 

 

 

 

(B). ALTERNATE FUEL REQUIREMENT DETAILS

 

 

 

 

 

9

Name of fuel

LPG

HSD

FO

LDO

LNG

Electricity

10

Calorific value (kcals/kg)

 

10100

10100

10100

10800

11000

11

Calorific value (kcals/litre)

10000

10000

10000

10600

860

12

Calorific value (kacals/kg)

10800

 

13

Rate of fuel (Rs.per kwh.)

 

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

5.00

15

Rate of fuel (Rs.per kg)

68.00

 

16

Inflation rate per annum

5%

17

Conversion efficiency

90%

90%

90%

90%

90%

90%

18

Combustion efficiency

85%

85%

85%

85%

70%

99%

19

Quantity of fuel required (kg.)

 

166

166

166

188

131

20

Quantity of fuel required (litre)

167

167

167

192

1670

21

Quantity of fuel required (litre)

155

 

22

Total amount

image

10535

6693

3346

3346

5750

8352

(C). PAYBACK CALCULATION

 

 

 

 

 

 

YEAR

OUT FLOW

INFLOW

BALANCE

 

 

 

80%

Fuel cost savings

 

 

 

depreciation,

 

 

 

IT savings of

 

 

 

30%

 

 

 

1

17000

4080

10535

2385

Negative sign indicates reverse cash flow !

2

2385

1020

11062

-9697

3

-9697

0

11615

-21312

That is inflow of cash !

4

-21312

0

12196

-33507

 

 

 

5

-33507

0

12805

-46312

 

 

 

(D). CONCLUSION

 

 

 

 

 

 

1

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

in  13 months