The audit recommended two options, including replacing a 15 year-old 33kW pump with a smaller 22kW pump, or replace the pump and add a variable speed drive. Energy savings of 4-11% and average emission reductions of 3.9 t CO2-e per annum have been estimated.
The 180 hectare farm in Giru, south-east of Townsville, produces sugar cane using flood irrigation with water sourced from aquifer bore pumps. Water use varies annually and is largely dependent on the level of rainfall. As pumps maintain a constant flow, the volume of water is varied with time of use.
The farm owner has indicated a willingness to replace the drive unit of the pump with a more energy-efficient motor (22kW) (Option 1 of the audit recommendations). Timing for installation will be during the next wet season period when rainfall provides relief from regular irrigation cycles.