Eric Jensen of Canadian Agtechnology Partner's Inc. demonstrates solar
water pumping
by Eric Jensen, Canadian Agtechnology Partners Inc. Olds, Alberta
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Eric Jensen of Canadian Agtechnology Partner's Inc. demonstrates solar |
The basis of this technology is the solar cell which produces DC electricity when exposed to sunlight. Developed originally to power space satellites the cost of solar panels has now dropped to where they are a viable option for many civilian applications.
Because there are no moving parts in a solar cell they never wear out. They withstand hail storms, high winds and extreme temperatures. Several manufacturers provide a I0 year warranty on their solar panels.
Solar Pumps
Since solar panels produce DC power the most efficient pumping systems utilize DC motors which can be connected directly to the solar panels. Some solar pumps are fully submersible. Others use a DC motor to power a centrifugal suction pump, or a submerged pump driven by a shaft or rod, similar to conventional windmill pumps. Solar panels are connected in series or parallel as required to operate the DC motors in their specified voltage range.
A wide range of solar pumps is now available, permitting selection of the most appropriate model for each application. Sizes range from a 1/8 h.p., 12 volt pump which operates on three 50 watt panels delivering 500 gallons/day at 100 feet of lift, up to a 3 h.p. 1,000 gpm, lowlift irrigation pump designed to operate on 60 panels.
Advantages
1. Water Demand Matches Sunlight
Livestock require maximum water in sunny weather, which is when a solar pump delivers peak output.
2. Simple to Install
No special equipment is required to install a solar pump. The panels can be mounted on a standard wooden post.
3. Simple to Service
Compared to windmills these systems are simple. Only the pump has moving parts. The solar panels will operate for years with no maintenance. If a wire gets loose it is simple to reattach because everything is at ground level. Some solar pumps have replaceable motor brushes. Other lower cost pumps are designed to be replaced as required every few years.
4. Portability
Small solar pumping systems can be easily moved from one pasture to another. This is a major benefit for rotational grazing.
5. Inexpensive
Generally, if a pasture is more than a kilometre from a power line it may be less expensive to install a solar pump than it would be to extend the power line. The savings in transformer charges will usually pay for ongoing pump maintenance.
Dugout Applications
One of the most popular uses of solar power is in pumping water from dugouts to waterers, keeping livestock out of dugouts. Advantages reported are reduced foot-rot, cleaner water, better gain and less dugout maintenance. A typical system might consist of a floating DC pump operated by 3 or 4 solar panels, providing 3,000 gallons/day at 10 ft. lift. This is enough water for about 200 cows with calves. The pumping equipment for the system would cost about $2,5.00. Sask Power provides a $500 grant for solar or wind pumping at remote locations. The water storage component of the system is extra.
It is essential to include adequate pumped water storage with any alternate powered pumping system used for watering livestock. It should be noted that solar and wind powered systems do not always keep up to the daily water requirements of cattle, because of low sunlight and low wind conditions. Generally 4 to 7 days water storage is recommended for these systems.
Sun, Water and Wildlife
Recent interest has also been expressed in using solar pumps to maintain water levels in wildlife habitats. This is a natural application for solar energy because maximum seasonal pumping matches peak demand in the wetlands.
