The most cost- effective way to install a solar geyser is to integrate
the collector assembly, cold-water supply and piping with the design
of a new house under construction. Solar geysers can easily be
installed in group houses and apartments, especially during
construction, if adequate provisions are made for piping, collector
assembly and cold-water supply. Proper load matching is required to
ensure that the capacity of the system installed is optimized to meet
the daily hot-water needs of the end-user.
Current prices of domestic SWHs are around Rs. 20,000 for a 100
1pd system. The life-cycle cost of energy of saved electrical energy
is Rs. 5600 per year at the point of end-user.
If the SWH is Purchased as an add-on to an existing geyser, the simple
payback period for the consumer would be 5.45 years. If the SWH is
purchased instead of a conventional geyser, the payback period for the
consumer would reduce to 3.58 years
Refer Table :
| Table
1: Cost benefit analysis of Solar Geyser 100 liters per day system |
| Capacity |
Rs. 3,000 |
Loan
|
Rs.
17,000(85%) |
| Cost
inclusive of the required hot & cold water piping, cold water
tank, structure, etc., |
Rs. 20,000 |
Return
desired on equity . |
18%
|
| Cost of
electricity |
RS.
3.00/kWh |
Working
period of system |
300 days
/ year
|
| Rate of
interest on debt |
5% P.A. |
COSTS
Electricity required for solar output |
Nill |
| Repayment
period |
5 years |
Repair/replacement & preventive maintenance @ 1.5% of the capital
cost, per year |
RS. 300 |
| Life |
15 years |
Interest
on loan |
Rs.
850/year |
|
Depreciation method |
Straight
Line |
Return on
equity |
Rs.
540/year |
| Cost of
an equivalent geyser of 25 lit. capacity including cost of
electricals |
Rs. 5,000
|
Depreciation |
Rs.
2,000/year |
|
FINANCING PATTERN
Equity
(user’s contribution) |
Rs. 3,000 (15%) |
Total costs |
Rs. 3,690/year |
|
