Harnessing Solar energy, Options for India

electrical energy output of the array. Depending on the total dynamic head and the required flow
rate of water, the pumping system can either be on the surface or submersible a and the motor can
run on either alternating current (AC) or direct current (DC). For AC pumping systems an inverter is
required. 32 Ratings of pump sets are chosen depending on the water requirements, size of field, total
dynamic head, type of irrigation (drip irrigation, use of sprinklers), etc.
Under the current scheme, the MNRE will provide a capital subsidy of 30% of the benchmark cost
(`210 per W p) and/or b 5% interest-bearing loans for installation of systems with a maximum
capacity of 5 kW p. 33
2.1. Analysis
Assuming a cost of `280 per W p for solar PV panels, our analysis showed that, when compared to
grid-connected systems at current rates, solar PV proved to be costlier. However, as an off-grid
application, when compared to diesel generators, it worked out to almost half the cost over a life
cycle of twenty-five years even at unsubsidised rates as can be seen in Tables 16 and 17). Other
studies have already shown the economic feasibility of solar PV over diesel pumps. 34 , 35 Therefore,
the former are a viable alternative in economic and environmental terms to diesel pumps in areas
where there is no or highly unreliable grid connectivity. Table 15 gives the underlying assumptions
of the analysis.
Table 15: Comparative Analysis of Diesel and Solar PV Irrigation Pump Sets: Some Assumptions
Assumptions
No of operating hours per year (in hours) 1,600
Cost of pump set (`) 25,000
Cost of solar PV panel per W p with battery (`) 270
Assumed flow rate for pump (gallons/minute) 2.6
Life cycle period (in years) 25.0
Cost of grid electricity per unit (`) 0.5
Discount rate (%) 10
Fuel consumption (litre/kWh) 0.33
a A submersible pump (or electric submersible pump [ESP]) is a device that has a hermetically sealed motor
close-coupled to the pump body. The whole assembly is submerged in the fluid to be pumped. Submersible
pumps push water to the surface as opposed to jet pumps, which have to pull water. Submersibles are more
efficient than jet pumps.
b Non-commercial entities: capital subsidy and interest subsidy; industrial/commercial entities: capital subsidy
or interest subsidy.
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