Choosing the correct solar pump size is important for reliable irrigation and long-term savings. A pump that is too small may not lift enough water, especially from deeper borewells. A pump that is too large can increase your investment without giving any real benefit. Many farmers select a solar pump based only on farm size, but the right pump depends on borewell depth, borewell yield, crop water requirement, total dynamic head, and available sunlight hours.
By SLEKA Engineering Team · July 7, 2026 · 4 min read
A correctly sized solar submersible pump helps you get the required water output within the available sunlight window. It also reduces the risk of dry running, motor stress, poor discharge, and unnecessary extra cost.
The most common mistake is choosing pump HP only by acreage. Two farms of the same size may need different pumps if their borewell depth, water level, or crop demand is different.
Before choosing a pump, check these details:
These details help calculate the correct pump HP and solar panel capacity.
First, estimate how much water your crops need per day.
Daily water requirement = Water required per acre × Total acres
Flood irrigation usually needs more water, while drip irrigation can reduce water use significantly.
Divide your daily water requirement by available pumping hours.
Required flow rate = Daily water requirement ÷ Sunlight pumping hours
Example:
If your farm needs 45,000 litres per day and you have 6.5 hours of good sunlight:
45,000 ÷ 6.5 = 6,923 LPH
So the pump should deliver around 7,000 litres per hour.
Your pump discharge should not be higher than your borewell yield.
For example, if your borewell gives 5,000 LPH, you should not install a pump that continuously draws 7,000 LPH. This can cause dry running and motor damage.
Total Dynamic Head, or TDH, is the total load against which the pump works.
TDH = Pumping water level + Delivery height + Friction losses
Example:
TDH = 55 m
A higher TDH means the pump needs more power to deliver the same water flow.
After calculating flow rate and TDH, match these values with the pump performance chart.
As a general estimate:
These are only starting estimates. Final sizing should be based on actual borewell yield, TDH, crop requirement, and pump performance curve.
For a 4-acre farm with drip-irrigated vegetables:
Since the borewell yield can support the required flow and the TDH is moderate, a 5 HP solar submersible pump with around 5–6 kWp solar panel capacity may be suitable, subject to the pump performance curve.
SLEKA Industries manufactures solar submersible pumps, motors, and controllers designed for Indian agricultural and borewell conditions. With the support of its dealer and installer network, SLEKA helps farmers select the right pump based on borewell yield, total dynamic head, and daily water requirement.
This helps farmers avoid undersized systems that fail during peak irrigation and oversized systems that increase cost unnecessarily.
The right solar pump size is not decided by acreage alone. It depends on your crop, borewell depth, borewell yield, TDH, and available sunlight hours.
Before buying a solar submersible pump, calculate your water requirement, required discharge, borewell yield, and total dynamic head. A properly sized system gives better irrigation, lower running cost, and long-term reliability.
For the right solar pump selection, contact your nearest SLEKA Industries dealer or visit slekaind.com.
For 5 acres with moderate borewell depth, a 3 to 5 HP solar pump is commonly used. The exact size depends on crop water demand, TDH, and borewell yield.
A 5 HP solar pump usually needs around 5 to 7.5 kWp solar panel capacity, depending on sunlight availability, pump efficiency, and head.
Yes. Deeper borewells increase TDH, which means the pump needs more power to deliver the required water flow.
Only if your borewell yield supports it. A pump that draws more water than the borewell can supply may cause dry running and motor damage.
