Energy costs have risen significantly over the past decade and cotton growers continue to look for ways to improve their on farm energy use efficiency. Pumping costs on irrigated cotton farms consistently account for 60 to 70% of total energy consumption on farm (Baillie and Chen 2008). The National Centre for Engineering in Agriculture (NCEA) has developed a Pump Efficiency Monitor (PEM) to assess energy consumption by the large mixed flow pumps found across the Australian Cotton industry. The ability of the Pump Efficiency Monitor (PEM) to continuously record pump station parameters provides data to assess combined motor and pump efficiency over an entire pumping event. This project highlights the importance to test each individual pumping set-up to identify the optimum operating point to achieve maximum efficiency. Significant cost savings are possible for individual growers and the industry collectively.