When you pair your well pump with a solar solution, one of the important things you need to figure out is its power consumption.
If your well pump runs often (e.g., on a farm or for a large household), knowing the watts helps you estimate how much electricity it uses daily or monthly.
Many technicians would tell you that the average household well pump typically ranges from 700 to 1,500 watts. But it doesn’t always apply to 240-volt systems.
There’s an easy way to calculate it so you can be sure. This guide teaches you exactly how.
TL;DR: Key Takeaways From This Article
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A 240V well pump typically uses between 960 watts and 2,880 watts, depending on its horsepower (HP).
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Check the amp rating on the pump's label for the exact wattage.
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The formula, Watts = Volts × Amps, works for every situation.
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Knowing the wattage requirements of your well pump allows you to pick the right solar panel model if you are considering getting one.
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Using solar energy for well pumps
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Find a high-quality solar-powered water pump from The Solar Store.
If you ever want to replace or upgrade your pump, knowing the voltage and power usage helps ensure the new one matches your power supply and doesn’t overload your system.
In the following sections, you will learn the simple formula for calculating the wattage requirement for a 240-volt well pump.
Calculating Well Pump Power Consumption
A watt (W) is the amount of power a device uses. You can calculate watts using this simple formula:
Watts = Volts × Amps
Volts (V) is the speed of the electric current flowing through the circuit, while Amps (A) measure the electric current flowing through the circuit at a given time.
We already know the pump is 240 volts. But we also need to know how many amps it draws (how much electricity is flowing).
You need to check your unit's specifications. After you confirm, the table below can guide you.
|
Pump Size (Horsepower) |
Amps (Approx.) |
Watts |
|
1/2 HP |
4 amps |
240V × 4A = 960W |
|
3/4 HP |
5.5 amps |
240V × 5.5A = 1,320W |
|
1 HP |
8 amps |
240V × 8A = 1,920W |
|
2 HP |
12 amps |
240V × 12A = 2,880W |
NOTE:
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This calculation is based on when the pump works normally (running wattage).
Pumps often use more power (starting watts) for a few seconds when they turn on. Sometimes, it’s 2 to 3 times higher.
Some people eventually choose to add a solar solution as a backup to their well pump. So, if your pump needs 500 watts to run, you’ll want a solar panel that can handle at least 700 watts also to cover the startup surge.
Factors that Determine the Wattage of 240V Well Pumps
From the method used in calculating well pump wattage, it takes more than the voltage to be sure. The following factors also matter:
1. Well Depth
A well pump lifts water from the underground source to your storage tank, pressure tank, or house.
It must overcome gravity and resistance. So, the deeper the water is, the harder the pump has to work.
What matters more is the static water level, also known as the water table, which is the point at which water accumulates inside the well.
For example, a well might be drilled 200 feet deep, but if water begins at 60 feet, the pump only has to lift water from 60 feet up, not the full 200.
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When water is close to the surface (say, less than 25 feet down), a smaller pump such as a ½ horsepower (HP) model is sufficient, using around 960 watts.
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When water is much deeper, such as up to 100 feet, a 1 HP or even 2 HP model of 1,920 to 2,880 watts is required.
2. Pump Size and Horsepower
Pump size usually refers to the motor's horsepower (HP). Horsepower is a unit that measures how much work a motor can do, in this case, how much water it can lift and how far it can push.
The higher the horsepower, the higher the wattage.
For example, a well pump with ½ HP and four amps will require 960 watts. However, that won’t be ideal for a pump with 2 HP and 12 amps, which may require up to 2,880 watts.
3. Pressure Settings and Tank Size
A higher pressure setting equals more wattage used per cycle.
Raising pressure from 30/50 to 40/60 makes the pump work harder. For example, a 1 HP pump might run longer to reach 60 PSI than to get 50 PSI.
Meanwhile, each startup draws 2 to 3 times the normal wattage (due to surge power).
So, a small tank may trigger 10 pump starts daily, while a large tank may need only 3. That difference adds up over time in your electricity bill and pump maintenance.
What About a 240v Well Pump Power Usage Calculator?
Platforms like energybot(dot)com make estimating your well pump’s power needs easy.
You just enter your pump’s voltage, horsepower (HP), and how many hours it runs daily. For example, a 1 HP pump uses about 746 watts.
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The actual usage can be 20–50% higher, depending on efficiency and load.
To calculate your pump's daily energy use, multiply the wattage by the hours it runs daily.
That said, many people find online calculators somewhat limited. Speaking with a real expert can provide more accurate and personalized advice.
That’s why we keep our lines open 24/7 at The Solar Store.
You can also use our Get Free Quote option to ask questions about your solar well pump.
Benefits of Using Solar Energy for Well Pumps
Grundfos SQFlex Pre-designed Solar Water Pumping Kit
Solar is the easiest way to get water if your well is far from power lines. And that’s just the tip of the iceberg regarding the benefits of using solar energy.
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Clean energy: Solar power doesn’t produce air or water pollution. So it’s better than fuel-powered generators or grid electricity that depends on fossil fuels.
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Quiet operation: If keeping your rural surroundings quiet is a priority, solar is the way to go.
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Save money in the long run: Although the upfront cost of solar panels can seem high, they quickly pay for themselves through lower energy bills.
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Off-grid is possible: Location should not hinder where and how you run your water system. That’s the freedom that solar-powered water pump kits give you. You can check our guide on the best well pump kits for your solar installation.
We've Got You Covered
The Solar Store is America's #1 Off-Grid Solar Power Systems provider. Based in Central Oregon, we live off-grid with wind and solar power, so we know and rely on the products we sell.
The solar-powered pumps in our inventory will keep working even when there’s no power from the grid.
Our solar pumps include:
And many more.
If you need expert guidance, contact us today to find the ideal solar-powered solution for your water pump. It’s time for you to experience the difference that quality and expertise can make in your water management system.