Read the full report, here.
By 9H Interns Zach Nelson & Ryan Tempel
Overseen and implemented by Cody Humphrey of the
9H Ranch and C&A Pet & Livestock Supply in Laramie, WY. Funded by the 9H Research Foundation, The University of Wyoming (UW) College of Engineering and Physical Sciences, UW’s College of Agriculture, Life Sciences & Natural Resources, the Wold Foundation, and the 9H Ranch.
Stock tanks are exposed to the elements in some of the coldest places in the county. This results
in a common problem ranchers face: freezing stock tank water. From having to chop ice out to allow
livestock to drink, to pipes and valves freezing, frozen stock tanks create an endless headache for
ranchers. The 9H Ranch outside of Laramie, Wyoming has had to “fight with our tanks all winter long”,
according to Ranch Manager and co-owner Cody Humphrey. One particularly elegant solution to this
problem is the geothermal stock tank. A geothermal stock tank not only keeps the water on the surface
from freezing, but also protects the plumbing from freezing – all without needing any electrical or
mechanical power. Properly installed, these geothermal stock tanks require little-to-no maintenance.
The geothermal stock tank works through geothermal heat transfer, using the heat in the earth
to keep the water from freezing. Using the same concept as a root cellar, the geothermal stock tank
keeps water deep enough in the ground such that it always stays at a constant temperature, about 52
degrees Fahrenheit. The temperature difference between the insulated water (below the ground) and
the cold water (at the surface in the tank) causes the water to circulate. This happens because the cold
water at the top sinks (its density increases as it cools), and the relatively warm water below rises (its
density decreases as it warms).
In short, a Geothermal Stock Tank (GST) is a 3-foot diameter culvert, about 10-feet long, capped
on one end, and buried vertically.