Solar-Powered Water Pump Maintenance, Part 1
By Kristin Lewis Hawkins
While low maintenance is a major selling point for using solar power to run the water pumps on your operation, there are still a few upkeep chores to perform and some things to keep in mind, especially if you want to guarantee the best return on your investment.
A benefit of solar pumping systems is a “set it and forget it” water source. They can be consistent and worry-free, but only with proper care and occasional maintenance.
This month, we will cover the energy production end of the system, including the physical mounts, energy elements and how the environment can affect your energy production.
Poles, modules and controllers
Most often, solar systems are installed on poles or metal framework anchored into the ground. While stationary poles and static frames can be almost maintenance-free, tracking systems that require frames to move with the sun can require a bit more upkeep. Consult with your frame or system’s manufacturer for any recommended operation and maintenance.
Photovoltaic (PV) panels, also known as PV modules, are the collections of energy-producing cells encased in glass surrounded by a frame, usually aluminum. These frames are installed in collections called arrays that are wired in series or parallel to power a solar pump system.
The panels themselves need little to no maintenance. The most likely problems you will encounter with panels are keeping them free of major dirt or debris. Regular dust should not cause a noticeable decrease in the system’s water output if your system array is sized correctly for your energy expectations. An efficient, dc brushless motor-driven solar pumping system that has enough wattage can still produce adequate water, even on cloudy days. It may not produce as efficiently as it would on a day with full sun, but it will still operate.
If you have birds that like to use the panels as a perch, you will inevitably get droppings or shadows, which will obscure direct light and could cause problems. Hard shadows from a solid nearby object or opaque liquid debris decreases the amount of light getting to the cells more than a rainy day or the softer shadows of passing clouds. Droppings or obscuring liquids should be cleaned off to enable the panels to operate at peak efficiency.
PV panels commonly come with a 20-to-25-year warranty to ensure the product operates safely and within an acceptable level of performance over time. Thus, they should not require any maintenance to keep within their performance goals.
Texas weather
According to Eric Macias, chief operating officer with Lorentz US Corp., a solar pumping product and system manufacturer, most reputable PV panels are designed to withstand some hail, wind and ice with minimal degradation to normally expected output. However, there is a limit that any PV panel, roof, or car windshield can withstand, and Texas is known for extremely high wind and very large hail.
While many PV panels are likely to survive a limited amount of moderately sized hail, weather conditions are highly variable and unpredictable. Check with your product’s manufacturer to see what methods of testing were used or to what level that product is expected to perform without compromising the system.
If severe weather has impacted your area, take a look at your solar arrays to assess the surface of the PV panels. Chips or small cracks to the panel surface may not be fatally damaging unless a seal is broken and water gets into the sealed system of cells. If this happens, they will need to be replaced.
Make sure nothing has fallen into or over your setup, such as downed limbs or building debris. Poles and frames can also be bent or broken in high wind situations, especially under the load of the wind-catching arrays. While your panels and arrays may be secure, the mounting system may have sustained damage.
Size Matters
One of the most overlooked culprits responsible for an underperforming solar pump is proper array sizing. Macias says a properly sized system should still be able to produce water, even on overcast days, by utilizing indirect light across the entire set of arrays.
“Many times the cheapest bid is not the best,” said Macias. “Always ask for a performance sheet that shows how many gallons per day the system will produce. This will ensure that you are getting the best value.”
Some landowners choose to oversize the number of panels on their system to ensure a more consistent production of power, and thus, water, despite the cloud situation. Solar systems are not used to store power, they are set up to pump and store water at consistent intervals or levels. As water use increases, it may be necessary to increase output, which is possible with a holding tank that meets your capacity needs and takes into account these changes.
Also, make sure your tank is in good shape and not leaking water.
The electronics and controllers that run most pumps are usually rated for outdoor use and weatherproof. It would still be prudent to open up doors and boxes on occasion to make sure no bugs, ants or other critters have found a way in and set up shop.
Next month we will cover the pumping end of the system, including pipes, pumps and keeping the water flowing. ❚
“Solar-Powered Water Pump Maintenance – Part 1” is excerpted from the May 2017 issue of The Cattleman magazine.