Submitted to: National Solar Conference
Publication Type: Proceedings
Publication Acceptance Date: March 15, 2010
Publication Date: July 1, 2010
Citation: Vick, B.D. 2010. Developing a hybrid solar/wind powered irrigation system for crops in the Great Plains. In: Proceedings of Solar 2010 National Conference, May 17-22, 2010, Phoenix, Arizona. 2010 CDROM. Interpretive Summary: A significant amount of crops in the United States are grown in the Great Plains, and most crops can significantly increase yield when they are irrigated. Since the energy used to pump water from underground aquifers for irrigation is primarily from limited fossil fuel sources that produce greenhouse gases, (natural gas, diesel, electricity from coal), it is important for farmers to begin switching to renewable energy resources such as wind and solar energy in order to continue to provide a stable food supply for the people in the United States. Renewable energy-powered irrigated crop production in southwestern Kansas and the northern Texas Panhandle is potentially cost competitive compared with existing fossil fuel powered irrigation systems. The ability of solar, wind, and a hybrid combination of solar and wind energy to meet irrigation energy requirements in the northern Texas Panhandle was analyzed. Average monthly data for solar energy resource, wind energy resource, rainfall, and crop moisture requirements were used to assess the renewable energy systems. Combining a winter crop (such as winter wheat) with a summer crop (such as corn or soybeans) better matched crop irrigation power needs with seasonal renewable energy production. The solar resource matched irrigation energy requirements better than the wind resource, but combining a wind turbine with a solar photovoltaic array had advantages over a solar energy option alone of reliability, less expense, and extra energy for other farm needs. At times when wind or solar energy is insufficient to power irrigation, either electricity from utility or bio-fuel (i.e. bio-diesel from soybeans which can be grown and processed on farm), can be used to pump irrigation water. Spikes in natural gas and diesel prices in recent years will likely become more common as demand exceeds supply. Therefore, switching to wind and solar energy for irrigation energy requirements and other farm energy requirements will enable farmers in the Great Plains to continue farming and reduce the dependence of the U.S. on foreign countries for energy and food.
Technical Abstract: Some small scale irrigation systems (< 2 ha) powered by wind or solar do not require subsidies, but this paper discusses ways to achieve an economical renewable energy powered center pivot irrigation system for crops in the Great Plains. By adding a solar-photovoltaic (PV) array together with a wind turbine and partitioning the center pivot irrigation system between a winter crop and a summer crop, the goal of a cost competitive large scale irrigation system powered by renewable energy may be attainable. Adding on-farm uses for the excess wind and solar energy during the winter months to produce valuable products on the farm enhances the prospects of a profitable system.