Solar-Powered Water Pumps for Livestock

Pump water for your animals with the power of the sun.


| October/November 2017



water spout

This solar-powered pumping system provides water for an 80-acre farm.

Photo courtesy Prashanth Vishwanathan/IWMI

While it’s not unusual for farmers and ranchers to let their animals drink from a creek, pond, or other surface water source, many are switching to alternative methods of supplying drinking water to their livestock. Solar-powered water pumps are easy to install and are a very reliable way to pump water from a well to a ground-level stock tank, or from a surface source of water up to a higher elevation. Some government agencies will even provide cash grants to farmers and ranchers if they agree to fence off grazing lands from nearby creeks and streams and install an alternative means of water provision, such as a well that uses solar-powered pumping methods.

Solar Pump System Components

The most basic form of solar pumping consists of a small direct-current (DC) solar pump, a pump controller, one or more solar modules, a replacement well cap, electrical wiring, and polyvinyl chloride (PVC) piping. Anyone who can use a screwdriver and pipe wrench should be able to assemble a solar pump kit. These systems are very basic. They don’t require power inverters or batteries, and working with 12- or 24-volt DC power is safer than connecting a 240-volt alternating-current (AC) pump to the electrical grid.

Solar pump. Systems requiring only a few gallons of water per minute from wells less than 100 feet deep will typically only need a small 12- or 24-volt DC submersible pump. Deeper wells or setups that need higher flow rates may require submersible pumps in the 48- to 90-volt DC range, powered by a much larger solar array. Solar-powered pumping systems are also available to pump surface water from a stream or lake up to a stock tank located at a higher elevation.

Pump controller. In addition to separate terminals to connect the pump and solar modules, a solar pump controller will also include wiring terminals for optional float switches, which can be used to stop the pump when the tank is full or when the well level is too low. While you could theoretically wire the DC solar pump directly to the solar array, the solar pump controller offers many special features that will increase system performance and provide overload protection for the pump motor.

For example, during early morning and late afternoon hours, the solar array may not provide enough current flow (amperes) to allow the pump motor to start. However, instead of remaining in this stalled condition with the motor windings heating up, some pump controllers can convert excess array voltage into a higher current, which will force the pump to start pumping during dim conditions.

While the reduced voltage during these periods will not allow the pump to run at full speed, additional water flow will be available when the system would normally not pump at all. Solar pump controllers also offer a convenient place to manually turn the pump on and off for service, and LED lights to indicate system status. I strongly recommend that any solar-powered pumping system include a pump controller.

coldspringfarm
9/22/2017 10:36:58 AM

We have used a solar pump for our cattle for 4 years and helped others install their own. An important note is that it is economical or easier to have batteries for this system. Instead, you need enough water in your storage tank to water the livestock during periods without sun. Example: 3 days without sun times 20 gallons per day times 10 head = 600 gallons of storage. Our storage tank is buried but is at the same level as the trough so it fills by gravity, keeping it simple. Only a small amount of the water surface is exposed, protecting from freezing. www.offgridoutfitters.org


bobstein54
9/22/2017 10:20:21 AM

It seems to me that in order to overcome these periods of low voltage that you would have a series of battery back up system(s) in place to overcome this and granted it might take a bit of arithmetic to accomplish this but when combined with a vertical axis wind generating system this should allow you to overcome any low/no-voltage problems.


bobstein54
9/22/2017 10:11:44 AM

It seems to me that in order to overcome these periods of low voltage that you would have a series of battery back up system(s) in place to overcome this and granted it might take a bit of arithmetic to accomplish this but when combined with a vertical axis wind generating system this should allow you to overcome any low/no-voltage problems.






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