The Complete Guide: Determining the Ideal Generator Size to Power Your Well Pump

Published On: December 26, 20210 Comments on The Complete Guide: Determining the Ideal Generator Size to Power Your Well PumpTags: , , Last Updated: March 24, 20248.3 min read

Are you tired of struggling to keep your well pump running during power outages? If so, you’ve come to the right place. In this complete guide, we will help you determine the ideal generator size to power your well pump, ensuring you never have to worry about a loss of water supply again. We understand the importance of finding the perfect generator size for your specific needs, and that’s why we’ve compiled this comprehensive guide. Whether you’re a homeowner looking for a backup solution for your well pump or a seasoned professional in need of accurate sizing information, we’ve got you covered. With our expert advice and step-by-step instructions, you’ll be able to confidently select the perfect generator size that meets the power requirements of your well pump. No more guessing or second-guessing. Our guide will provide you with all the information you need to make an informed decision and ensure a reliable power source for your well pump. So, let’s dive in and find the ideal generator size for your well pump today.

well with well pump

Well pumps are a reliable source of getting water for most houses, especially commercial farms, and large residential areas. Typically, the pump needs electric power to rotate its motor to bring up water from the ground. That’s why it is crucial to supply electric power to keep the pump running. Otherwise, you have to pass without drinking water, cooking, or bathing. But sometimes, it can be difficult to power the pump when a blackout occurs. In this situation, using a generator will be an excellent way to power the pump to make the water supply continuous.

You may think that a generator can run your well pump. Typically, it totally depends on what type of generator you use. You will require the perfect generator for your well pump, as not all generators can serve perfectly.

Does Your Well Pump Need a Generator?

You may notice that we don’t use any more buckets and ropes to bring up water from the well. Technology makes the system easier than before through the invention of the well pump. Nowadays, using an electric well pump, you can easily get water from the depth of the well. But during a blackout, when the pump has no electricity supply, getting water will be challenging. In that situation, a whole home generator can back up your pump to ensure the getting water supply continuously until the electricity comes back. Furthermore, you can use a generator to power a well pump in places where electricity is not available.

Supplying power to your well pump will be easy for you through a portable generator. Besides, by using a generator for your well pump, you can also run any other household items that run off due to power outages. In this way, you’ll ensure that specific or every appliance is always powered on.

Can I Run My Well Pump With a Generator?

Typically, the short answer is yes; you can run your well pump through a generator. Even if you wish to use a portable generator to power the well pump during power outages, you can do it by plugging directly. The process mainly relies on the wattage of your well pump and generator. For instance, if you have a well pump with ⅓ HP and 750 watts. The starting watts of the pump will be 1500 watts. That means a generator with 2000 watts will smoothly run your well pump. Now you may wonder how you can estimate a generator’s wattage. For that, check out the section below to know how you can determine the perfect size generator for your well pump.

What Size Generator Does a Well Pump Need?

The size of your required generator for supplying electricity to a well pump completely depends on the wattage of your pump. It is impossible to determine a generator’s exact size without knowing how powerful your well pump is. Besides, every electronic device has a specific starting and running wattage. As all electronic devices have different wattage, the starting and running wattage will differ. Remember, starting watts are always higher than running watts. That’s why you have to determine your generator’s starting and running wattage. Suppose the power of your well pump is 1/2 HP. As we know, 1HP = 746 watts, so your pump’s running wattage will be 373 watts.

well pump powered by generator

That means you will need a generator that will supply at least 10% more wattage than the initial watt. Experts recommend using at least a 2000 watt generator for a well pump so that you can easily supply electricity to your well pump as well as other small appliances. For your convenience, below we have inserted a table with estimated data of the traditional well-pump with their starting and running wattage. This will help you to get an idea of what size of generator you will need to power your well pump.

Size of Well PumpRunning Wattage(Approximately)Starting Wattage(Approximately)
⅓ HP Well Pump750 Watt1500 watt
½ HP Well Pump900 watt2000 watt
¾ HP Well Pump1500 watt3000 watt
1 HP Well Pump2000 watt4000 watt
1½ HP Well Pump2500 watt5000 watt
2 HP Well Pump3750 watt7500 watt

Is a Portable Generator Capable of Running a Well Pump?

People usually think a portable generator can’t be used to run a well pump. Typically, it is completely nothing but a misconception. The right information is you can run your well pump with a portable generator. Most people have already started using portable generators to power their well pumps during blackouts. For that, it has become more and more common in every house. But you have to find a perfect generator whose wattage is higher than the starting watts of your well pump. You can easily calculate the required generator size by following the process discussed in the above section. Those who depend on the well pump to get water, face difficulty during power outages. A portable generator will remain your well pump power supply continuous. As a result, you will get a continuous water supply from your well pump even if there are blackouts.

Is it Possible to Power a Well Pump With a Solar Generator?

During power outages, many people cannot use their well pumps because they require electricity. In that case, using a solar generator can be a good way to supply electricity to your well pump. This way, you can ensure an uninterrupted water supply even when the lights are off due to power outages. As solar generators are a renewable source of supply electricity, you can minimize your monthly expense. Now you can think about whether a solar generator would power a well pump. Well, if the solar generator meets your well pump requirements, you can easily run your pump through this generator. For determining the requirements, you have to estimate the solar generator and well pump wattage. If your generator wattage is higher than the starting wattage of the well pump, then you can run your pump.

generator for well pump

A Guide to Pick the Right Generator for a Well Pump

Before purchasing a generator, especially for a well pump, you have to keep in mind several factors. Considering these factors will assist you to pick the right generator. Some significant factors are below:

Power Rating

As we said before, determining the wattage of your generator and well pump is crucial to running the pump properly. You will find the pump’s starting and running wattage information on a label that is integrated into your pump. On the other hand, you will get the generator wattage from its label printed on the generator. Ensure your generator meets the requirements of your well pump.

Generator Type

You will find three types of generators on the market: inverter generator, convectional generator, and standby generator. Inverter and convection are portable generators with movable facilities. On the contrary, a standby generator is a fixed type of generator you can’t move. This type of generator is good for large homes and industrial areas.

Construction Integrity

Generators are mechanical tools that make noise and vibrate a lot. The construction of any generator determines how well it will deliver power and how long it will last. So, if you need a heavy-duty and long-lasting generator, ensure the materials used in the generator are durable and heavy-duty. In addition, before buying a generator, make sure the vibration rubber pads are put in the right place.

Fuel Type

After considering the above factors, you have to check what type of fuel is needed to run your generator. You will find some generators run on oil and gas and others on gasoline and diesel. Some generators may be run on dual fuel (gas or propane), the most accessible fuel. Besides, using dual-fuel facilities will help you to minimize your expense costs.

Fuel Efficiency

Fuel efficiency helps to determine how much a generator will convert energy in fuel into electricity. You may think you have to refuel after every hour, but the fact is this is a waste of money. A generator should feature maximum fuel efficiency. For that, purchase a generator with a fuel efficiency feature that will help you to save your total cost.


Using a generator is a good way to supply electricity to your well pump during power outages. This way, you can ensure a continuous water supply when electricity is unavailable. However, some people may think about whether a generator can run a well pump. That’s why, through this context, we have tried to let you know if it is possible to run a well pump using a generator.

If you read this context, we hope you might have understood what’s requirement is to need a generator to run your well pump. Typically, if the wattage of your generator is more than the starting wattage of your well pump, you can run  your pump.

Share This Tip With Your Friends!

About the Author: Handyman tips team

The Handyman Tips Team is a group of authors that provides tips on the Handyman Tips website. The Handyman Tips team consists of real handymen, contractors, carpenters, woodworkers, and experts in home repairs, appliance repairs, and landscaping. The team is always there for visitors to the Handyman Tips website. If you can't find the answer to your question on the Handyman Tips website, one of them will reply to you almost immediately if you contact them through the Ask the Handyman page!