As the saying goes, necessity breeds invention. Farmer Roger Barton needed to water his crops, and he needed fuel to run his irrigation system. The trouble came in 2008 when diesel prices reached $4.28 per gallon. (Currently, they’re about $4.12).
So Barton began looking for ways to circumvent the rising costs of keeping his hydraulic center-pivot irrigation system running over his alfalfa. These wheeled sprinkler systems rotate around a central point in the field. This allows for more uniform and controlled watering and is what forms those quilt-like circular crop patterns on the land.
What he eventually came up with was to couple his irrigation system with a hydro turbine.
Water comes to Barton’s farm from the mountains via a gravity pressurized pipe at 85 pounds per square inch (psi). But his system only needed a pressure of about 43 psi, and higher pressures sometimes damaged his sprinklers. After consulting with engineers and a pump company, the farmer decided to add a hydro turbine to his gravity flow irrigation system. The extra water pressure powers a turbine which puts the machinery into gear. No diesel required.
Barton’s estimated operating costs are now less than $100 a year. Designed by Redmond Irrigation, the system filters any sand and gravel within the water that might damage the turbine.
Ron Francis of the Natural Resources Conservation Service - Utah writes:
Now when the water enters his new system it travels through the vanes of the turbine, causing the turbine to spin and turn a hydraulic pump that pumps hydraulic fluid through gears that turn the wheels, moving the long irrigation boom around the circle. Along the way the water pressure is reduced to about 45 psi, just the right amount to keep it from damaging the sprinkler heads.
“This new system is terrific,” Barton says. “It not only did away with a $3,500 annual fuel bill, but it eliminates emissions from the old motor, avoids storing fuel on the farm and lessens our dependence on foreign sources of oil. I’d say that’s a win-win for everybody.”
But depending on the specifics of farm location, equipment and water needs, the set-up might not be for everybody. As a general guideline, the National Sustainable Agriculture Information Service says the turbine/center pivot combo works well when the available water pressure is 40 more psi than needed by the irrigation system. Barton cautions that new nozzles might be necessary to adjust to the water pressure change and a backup diesel could be useful when moving the pivot around the farm.
For Barton, designing, equipment and installation was $17,000, with an expected payback period of three years or less. Right now in Utah, the Environmental Quality Incentives Program offers to share 65 percent of the costs.
Related on SmartPlanet:
- Checking agricultural water levels from space
- Can U.S. farms produce food without relying heavily on fossil fuels?
- New irrigation system helps farmers conserve water
Images: Doug Wilson/USDA Agricultural Research Service and NASA Flickr_Sam Beebe / EcoTrust
