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SOLAR
POWER
PV Modules Replace Generator
on Gold Creek Cattle Operation
Every
summer, Jim Tomlinson pastures 20-25 cow/calf pairs or
replacement heifers in timber and grassland several miles
from the town of Gold Creek, Montana. The area is steep,
rugged, and remote. A creek flows along one side of the
property but "sinks" beneath the surface and goes
dry along the way. To give his cattle a reliable water
supply, Tomlinson installed a stock-watering system about 10
years ago.
The nearest power line was
about two miles away, so he decided to use a
gasoline-powered generator. He pumps water from a 160-foot-deep well to a 1,350-gallon underground cistern. Water flows
from the cistern by gravity into a 700-gallon stock tank.
The well and tank are located on a high bench and give the
cattle access to forage far from the creek. Tomlinson uses
solar-powered electric fencing to control cattle movement,
as part of an intensive grazing strategy.
The
gasoline-powered pumping system gets the job done but has
created some headaches. About every five days, Tomlinson has
needed to travel 45 minutes each way from his home just to
run the generator and fill the stock tank. While he would
normally come up to check on the cows at least once a week
anyway, he’s been forced to stick to a rigid schedule for
watering. This has presented problems during haying and
irrigating seasons. A few years ago, Tomlinson also needed
to replace a generator that was stolen.
Working with the National
Center for Appropriate Technology, Tomlinson installed a
solar-powered pumping system in June 2000. The system, supplied
by Sunelco in Hamilton, Montana, uses two 120-watt
photovoltaic modules, a passive tracking rack, and a
submersible diaphragm pump with a maximum flow rate of just
under one gallon per minute. The panels are located about
100 feet from the well to avoid shading from trees.
Tomlinson
increased his storage capacity by installing a second
700-gallon watering tank next to the first one. This will
ensure adequate water during cloudy weather, when solar
pumping will be reduced. After the cows are moved off the
pasture each fall, Tomlinson plans to remove the tracker and
panels and store them at the ranch to avoid vandalism during
hunting season.
The main advantage of solar
pumping is that it should be reliable and nearly maintenance
free, keeping Tomlinson’s tanks full all summer long and
freeing up his schedule during the busy times of irrigating
and haying. An unexpected benefit is that he has been able
to continue pumping and watering his cattle as usual last summer (2000), despite the drought in Montana. Because of
the severely dry conditions and extreme fire danger, he
would not have been allowed to run a gasoline-powered
generator in the forest this summer.
NCAT
photos
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