by Matt Booher, Extension Agent, Agriculture & Natural Resources
Virginia Cooperative Extension
Many cattle producers rely on direct access to surface waters, despite wanting to fence out riparian areas and protect water quality. There are many reasons for this, including cost. This is especially true on leased land, where drilling a well can be hard to justify. In some cases, a lack of electrical service may preclude standard watering systems altogether. Thankfully, using solar power to pump water can be a reliable and affordable alternative.
For the past five years, a team within Virginia Cooperative Extension has worked with producers in the Shenandoah Valley to build and test solar-powered watering systems for pumping from surface waters. While we have focused primarily on semi-permanent use, solar can be adapted to a permanent setup as well. Through this project, we’ve found solar-powered watering systems to be affordable, effective, and simple to install. Like any system, however, solar pumping systems require regular observation and maintenance.
Thus far, the solar watering systems in this project have been of similar design, constructed as portable units that draw from surface water (ponds, creeks, and rivers) using submersible or surface pumps. Each system was designed to pump from a surface water source to a plastic reservoir (e.g. repurposed bulk cage containers or poly tanks), through 1” diameter or greater, black plastic (PE) pipe laid aboveground or buried to a shallow depth. The reservoir stores and releases water via gravity flow to a valve mounted on a stock trough, and is typically sized to hold 3-days’ worth of water in the event of cloudy weather or other issues. Full-flow float valves under low pressure situations ensure that livestock demand during an individual watering event will not exceed the recharge rate of the trough. A large stock trough can also help to ensure plenty of water is available if the entire herd waters at once.
Wired and wireless sensors are available for installation in order to automatically shut off the system and stop water flow to the reservoir once it is topped-off. This project also explored the use of a pressure switches to turn off the pump when the system storage was full, but found that it sometimes worked inconsistently depending on the site.
Our team worked with many farms to test them under different conditions and water sources. Farmers typically maintained a limited access point to the water source for emergencies.
This project has used water from spring-fed ponds, springs, creeks, and rivers; and pumped against anywhere from 5 to 125 feet of head (pumps are capable of tackling greater elevation, but it varies by the system). In most cases, we established new watering points 300-1,000 feet from the water source, which allowed producers we worked with to excluded livestock from their sensitive riparian areas and shift grazing to upland pastures that had previously been underutilized. In many cases, the use of poly-pipe allowed farmers to establish multiple watering points within a central setup, which allowed for rotational grazing and the resting of pastures for improved grass growth. These systems were designed to operate during the freeze-free months, although some system modifications such as adding weep holes and pressure relief valves, can extend their use through light freezes.
How can you get started?
This site shares some of the operational experiences and introdcuctory informational resources to help you further explore these types of systems. Generally, however, solar panels and compatible pumps can be purchased from retail stores or online, as individual components or as ready-to-go kits. In general, small systems capable of pumping to 3-6 gal/min. and watering a herd under 30 cows can be purchased for less than $3,000. This doesn’t include any of the other system parts such as reservoirs, stock tanks, pipe, or plumbing components. Installing your own solar-powered watering system requires some knowledge of electricity and plumbing. Additionally, you will want to consider basic site preparation such as leveling and erosion control at the trough, anchoring and protecting the pump in the water source, and fencing infrastructure.