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Varisun Solar Pumping FAQs

Solar Pumping System

27 kW Solar Pumping System at Full Belly Farm


Q: How much does it cost for a VariSun Solar Pumping System?
A: $13,620 buys you a direct solar system that operates your 3 phase motor. Your motor can be a pump, blower or compressor. For $13,620 you get the VariSun motor controller and enough power to operate a 3HP pump during the day, free.

Q: What information do I need to provide to get an accurate estimate?
A: The VariSun systems are sized to specific size motor. The more information you provide, the more accurate the estimate. But the basics include the size of your motor (horsepower/HP), how many gallons per minute (GPM) your well produces, or how many CFM (Cubic Feet per Minute) and vacuum. For a quick estimate, please fill out this form.

Q: Do you need my Electric bill?
A: If your pump is currently grid-tied, providing us with a history of your electric bills showing actual power usage will also give us an accurate picture of how large the system needs to be.

Q: How big of a pump can you power with a VariSun solar pump?
A: VariSun systems are scalable to meet your power needs. Larger systems may require more space to produce power. VariSun can operate any three-phase motor from 3 – 50 HP. To get an idea of what size system you might need, download and view this spec sheet for the VariSun.

Q: My well is in a remote location, away from any grid infrastructure. Can I use the VariSun system in this situation?
A: Yes! VariSun is particularly well suited for off-grid applications. Our proprietary technology allows you to harness the sun’s energy directly, without inverters. There is no need for grid back-up. Just add sunshine.

Q: Is the VariSun a fixed or mobile system?
A: It can be both. Our pod is 10-panels on a shippable self-standing racking system. Each power pod is capable of running a 3 HP motor. The pods can be anchored to the ground with concrete footings. The skid-mounted pods can be transported with a forklift or on a flatbed trailer. If you have multiple wells, the pods can quickly be moved.

Q: Can I install my VariSun system myself?
A: The VariSun system is prefabricated is more shop and tested. The VariSun system is designed to be “plug and play.” Set up is pretty straight forward. Just unfold the racking system, secure and turn on. We provide sufficient instructions to enable your electrician to connect your VariSun system to your pump. We do offer installation and delivery services. We include shipping and/or installation fees in our estimates as appropriate.

Q: Can I use a VariSun system to power my single-phase pump?
A: The VariSun controller is a variable speed controller explicitly designed to work with a three-phase pump.

Q: How much money can I save by switching from diesel to solar?
A: The savings will depend on the price per gallon you pay and the number of hours you run your diesel generator, which determines your gallons per week usage. However, with diesel prices running close to $4 per gallon, we generally estimate that your ROI converting from diesel to solar will usually be under two years, and sometimes less than a year with various Federal and state incentives. There is a 30% federal tax credit for renewable energy plus funding for up to 65% of the conversion cost through the CEC REAP program. Several time-sensitive grants are available.

Q: How much money can I save by switching my water pump from grid electric to solar?
A: Your savings will be your cost to run the power for the pump every month. Most systems pay for themselves within a few years. Your cost per kWh and the amount of time you run your pump determine your savings. However, with electricity rates in California set to increase significantly over the next three years, the payback period could shorten.

Q: Should I go with direct solar or a grid-tied system for my pump?
A: There are several factors to make this decision: How often and when do you want to run your pump? Is it essential to have back-up power for your pump? Can you meet your pumping needs during available daylight hours using only solar energy? These are among the factors that will help determine which option is best for you.

Q: How does the VariSun controller work with direct solar?
A: Our proprietary VariSun controller starts with DC power, so it doesn’t need to convert AC power to DC to efficiently control the speed of your three-phase AC motors.

Q: Can I use a VariSun system with my existing pump?
A: If your current pump runs with a 3-phase electric motor then the VariSun system should work with it.

Q: If I don’t have a pump yet, can you still design a system for me?
A: Absolutely! Based on the information you provide on the online form, we can spec out a VariSun system for you. Our systems balance demand and production: The solar array and motor controller are sized to the motor size.
To spec your complete VariSun system, please fill out this form.


If you have any other questions, please feel free to contact us.