UPSC Prelims 2020 Q88: Science & Technology – Energy & Environment
- (a) 1 only
- (b) 2 only
- (c) Both 1 and 2
- (d) Neither 1 nor 2
Answer: (d) Neither 1 nor 2
Explanation
Solar Water Pumps: Testing the Two Restrictions
| Statement | Claim in the question | Verdict | Reason |
|---|---|---|---|
| 1 | Solar can power surface pumps but NOT submersible pumps | FALSE | Solar PV systems drive both surface pumps and submersible pumps. India's PM-KUSUM scheme deploys solar submersible pumps at large scale for groundwater irrigation. |
| 2 | Solar can power centrifugal pumps but NOT piston pumps | FALSE | Solar PV output can be conditioned (DC-DC and inverter stages) to drive AC or DC motors turning centrifugal, piston or helical rotor pumps. Pump displacement type is independent of the power source. |
Both statements 1 and 2 are wrong. Answer: (d) Neither 1 nor 2.
Answer: (d) Neither 1 nor 2.
Why each option is right or wrong
- (a) Incorrect. Statement 1 is false - solar-powered submersible pumps are widely deployed under PM-KUSUM and MNRE schemes.
- (b) Incorrect. Statement 2 is false - piston (positive-displacement) pumps can also be run on solar PV with the right motor drive.
- (c) Incorrect. Neither statement is correct; both wrongly restrict solar pumping to one pump type.
- (d) CORRECT. Both statements are wrong. Solar water pumps power surface AND submersible designs, and can drive centrifugal AND piston pumps. Pump architecture is independent of whether the source is grid, diesel or solar PV.
Key point
Solar water pumps are not restricted by pump geometry. They run surface + submersible pumps and centrifugal + piston pumps. Both statements in the question are false. Answer: (d) Neither 1 nor 2.
Remember
Solar water pumps can power both surface AND submersible pumps, and both centrifugal AND piston-type pumps. Neither of the restrictions in the question holds. Answer: (d) Neither 1 nor 2.
Common mistakes
- Assuming solar PV cannot supply the higher starting current needed by submersible motors. Modern MPPT drives handle this routinely.
- Confusing pump-displacement type (centrifugal vs positive-displacement) with the power source. Any pump that runs on an electric motor can run on solar with a suitable drive.
- Overlooking PM-KUSUM (2019), which subsidises solar submersible and surface pumps across states.
Exam tip
Solar pumping quick facts: (i) PM-KUSUM Component B and C fund standalone and grid-connected solar pumps; (ii) MNRE guidelines cover 1 HP to 10 HP solar pumps; (iii) Both AC (with inverter) and DC (brushless) motor pumps are eligible; (iv) Surface pumps for low head, submersible for deep tubewells - solar drives both.
Sources
- Ministry of New and Renewable Energy (MNRE) - Solar Water Pumping Programme (PM-KUSUM)
- MNRE Specifications for Solar Photovoltaic Water Pumping Systems