PUMPING PLANT EFFICIENCY, FUEL OPTIONS AND COSTS

Energy costs have a major impact on production costs in agriculture. Irrigated agricultural has additional energy sensitivity due to the cost of pumping irrigation water. As pumping energy costs increase, irrigators have been exploring energy options. While changing energy sources can sometimes be economical option, it can require large up-front investment costs with little guarantee that the alternative energy source will remain cost competitive. Before changing energy sources, irrigators should evaluate the performance of their current pumping plants, as wear and changes in pumping conditions over time can cause substantial loss in pumping plant efficiency. This results in the increased use of fuel for the same or less amount of water pumped. The irrigation fuel or energy bill is composed of two parts. The first is related to pumping plant performance and the second is related to crop irrigation management. Total fuel bill = Pumping cost/Unit Volume of Water x Volume Applied The pumping cost per unit volume of water depends on well efficiency, pumping plant efficiency and fuel cost. The major influences on the total volume applied are related to management issues, such as irrigation schedule for the crop selected and the irrigation system efficiency. Reducing the total volume applied reduces the fuel bill proportionately, so if the amount of water applied is minimized with good irrigation scheduling and high application efficiency, the fuel bill will be minimized based on pumping volume. Good irrigation management practices and high system efficiency are the subject of other presentations. The focus of this discussion will be on the pumping cost per unit volume of water