How To Calculate Submersible Pump Efficiency
A pump may look like a simple machine, but how well it uses electricity decides your water cost every month. This is why Submersible pump efficiency matters. If your pump is efficient, you get more water with less power. If not, you pay more and still struggle with water flow.
This guide explains Submersible pump efficiency in a very easy way, with a clear formula and example and also based on what type you need, like DC submersible pumps or AC submersible pumps, so that anyone can follow.
1. What is Submersible Pump Efficiency?
Submersible pump efficiency means how well a submersible pump turns electrical energy into useful water flow.
In simple words:
“How much water do you get for the electricity you spend?”
A pump with higher efficiency wastes less power. So it’s all based on the efficiency of pumps. This applies to all setups, whether you use a submersible water pump at home, a submersible well pump in villages, or a farm pump in deep borewells.
2. Key Formula to Calculate Pump Efficiency
To calculate Submersible pump efficiency , you need two things:
1.Water power output (how much useful work water is doing)
2.Electrical power input (how much electricity the pump consumes)
Formula:
Pump Efficiency (%) = (Water Power Output ÷ Electrical Power Input) × 100
Water power output depends on flow rate and head (explained below). Power input is what your meter shows when the pump runs.
This same formula applies to a normal pump, a solar-powered submersible pump, or a borewell setup with a submersible pump motor.
3. How to Measure Flow Rate and Total Head
To use the formula, you need:
Flow Rate
Flow rate means how much water the pump gives in a certain time.
Example: “200 litres per minute.”
You can measure it by letting water fill a known tank and timing it.
Total Head
Total head means how high the pump pushes water from the water level to your outlet tank or pipeline.
It includes:
- Borewell depth + lifting height
- Pipe losses (because water loses pressure in pipes)
For deep borewells, the total head is often high, especially when the borewell motor is working hard in summer.
4. Example Calculation (Simple & Practical)
Let’s say your pump gives:
- Flow Rate = 120 litres per minute
- Total Head = 30 metres
- Power Input (meter reading) = 1.5 kW
Step 1: Convert flow rate to litres per second
120 LPM ÷ 60 = 2 litres/second
Step 2: Calculate water power output
Water Power (kW) = (Flow × Head × 9.81) ÷ 1000
= (2 × 30 × 9.81) ÷ 1000
= 588.6 ÷ 1000
= 0.59 kW
Step 3: Efficiency
Submersible pump efficiency
= (0.59 ÷ 1.5) × 100
= 39%
So your pump is working at about 39% efficiency. A well-maintained pump usually performs around 40–60% depending on design and condition.
5. Factors That Affect Submersible Pump Efficiency
Many things can reduce Submersible pump efficiency
- Wrong pump size: If the pump is too big or too small for your depth.
- Low voltage: Makes the motor strain and waste power.
- Worn-out parts: Impellers and bearings lose performance over time.
- Pipe leakage: Water loss reduces output.
- Dirty water or sand: Damages internal parts faster.
- Improper stage selection: More stages than needed waste energy.
Even if you buy the best submersible pump, efficiency drops if installation and maintenance are poor.
6. Tips to Improve Your Submersible Pump Efficiency
Here are simple ways to improve Submersible pump efficiency
1. Choose the correct HP and stages
Match the pump to the borewell depth and water need.
2. Use good pipes and fittings
Reduce leakage and friction losses.
3. Check voltage regularly
A stable supply helps the submersible electric motor run smoothly.
4. Clean and service yearly
Sand and rust reduce flow. Cleaning restores performance.
5. Avoid dry running
Running without water damages the motor quickly.
6. Go solar if power cuts are frequent
A solar submersible pump or solar submersible setup runs steadily in daytime and avoids voltage issues. Pairing it with a reliable solar-powered pump system also reduces monthly costs.
7. Why Pump Efficiency Matters for Farmers & Industries
For farms and industries, Submersible pump efficiency directly affects cost and work output.
- Farmers: Higher efficiency means better irrigation using less power or fewer solar panels.
- Industries: Efficient pumping reduces daily operating costs and keeps production stable.
- Homes: Better efficiency lowers electricity bills and gives strong water pressure.
When efficiency is low, the cost of submersible pump ownership becomes high over time, even if the pump price looked cheap at first. So if you’re planning to buy a solar-powered pump, efficiency should matter as much as the submersible pump price when you buy.
FAQ
Yes, when sized correctly and maintained, they give high water output for the power used.
It is used to lift water from borewells, wells, tanks, farms, and industrial water lines.
Submersible pumps are better for deep water sources because they push water more efficiently.
Not if efficiency is good; low efficiency is what causes high bills.
Yes, most pumps can be serviced or repaired if damage is not too severe.
