Savings & Return on Investment
An average family of four uses 125 Liters of hot water
per day at a cost of Rs. 6000 per year
The typical Solar Water Heater will save 90% of the heating
costs, or Rs. 5500 per year.
A typical family of 4, with 30 liters per person.
Total water quantity: 125 Liters. At 600C
Considering a showering Temperature: 430C
Ambient temperature:230C
=
(60-23)0C.
Total heat requirement Q=mCpDT
Cp=4200J/Kg-0K
Q=125X4200X37=19425000Joules
Equivalent electrical heater required considering 85% conversion
efficiency.
Qelectrical = 19425000/0.85 Joules.
22852941 Joules
Equivalent electricity Units = 22852941/1000X60X60 kWh
=6.348 kWh.
Electricity cost= Rs. 3/unit.
Total monthly electricity cost=6.35X30X3=571.5Rs.
Annual cost= 571.5X12=Rs.6858.00 » 6850.00
typical payback with electrical geyser installed
Cost of one HYKON solar water heater-17500 Rupees.
Payback period. 17500/6850=2.55 years.
Considering the rising electricity cost and the usage pattern.
An average pay back of 2 years is a reasonable assumption.
Typical pay back replacing electrical geyser
Cost of one electrical geyser- 5000 Rupees.
Average household having 2 geysers total eqpt. Cost-10000
Rupees.
Net pay back period=(17500-10000)/6850=1.1 years.
Having 1 electrical geyser Cost-5000 rupees.
Net payback= (17500-5000)/6850= 1.8 years.
