Case Study 1. Iron Oxide Residues Reduce Pump Efficiency

A Burdekin sugarcane farmer furrow irrigates 50 hectares of sugarcane using mainly ground water. The farm is located in an area in which iron bacteria is prevalent in the groundwater. Prior to the energy efficiency assessment conducted through the EEGAI project, the farmer suspected that his pump efficiency at this particular site was likely to be low since it had received minimal maintenance over the years. The assessment revealed excessive suction at the pump inlet, indicating a restriction of flow in the bore. Upon dismantling the pipe and pump assembly it became obvious that iron oxide build up in the pipeline had dramatically reduced the capacity of the pipe to deliver water.

Case Study 2. Negative Impacts of Valve Use on Efficiency

Burdekin sugar cane farmer Paul Villis flood irrigates approximately 400 hectares of sugarcane using both groundwater and surface water. He has 25 pumps in total and many are equipped with a butterfly valve on the discharge pipe to allow the flow of water to be regulated (Figure 3). Paul regularly used the butterfly valve to restrict the flow of water because he believed that restricting the flow of water using the butterfly valve was more cost effective than running the pump at full flow. This is because at the lower flow rate, the pump was drawing the least amount of amps. Paul had three settings on the butterfly valve that he regularly used which allowed full flow, partial flow and low flow of water.

Case Study 3. Selecting an Appropriate Electricity Tariff

A Burdekin sugarcane farmer uses a total of 12 pumps to irrigate 215 hectares of sugarcane. Groundwater is pumped to irrigate the crop using both furrow and drip irrigation. This farmer has been regularly reviewing his pumping tariffs for the past twenty years, generally using the Tariff Comparison Service provided by Ergon Energy. However, he found this service lacked detail regarding farm particulars such as specific site information and irrigation timing requirements. A process that could help him understand how to better manage irrigation timing was needed. The Energy Efficiency Gains for Australian Irrigators project was able to provide the tools for this farmer to make the most appropriate decision to allow him to minimise his energy costs and also maximise flexibility of his pumping infrastructure. The majority of his pumps were on Tariff 65, a transitional ‘time of use’ tariff which offers a low rate for electricity used within a fixed 12 hour period.

Case Study 4. Cost Implications of a Collapsed Underground Pipe

Burdekin sugarcane grower John Davenport uses two pumps to furrow irrigate 52 hectares of sugarcane using a mixture of groundwater and channel water. Prior to the energy efficiency assessment, he was quite happy with the volume of water the pumps were producing, and believed that his pumps were running efficiently. An energy efficiency assessment was carried out on his open water pump. The pump was operating at an acceptable level of efficiency for the duty being performed, however concerns were raised due to the higher than expected delivery pressure and the total power consumption required to move the water to the delivery point.

Case Study 5. Reducing Costs through Enhanced Irrigation Efficiency

A lower Burdekin sugarcane farmer furrow irrigates 50 hectares of sugarcane using groundwater with approximately 17 applications per year. This results in electricity being one of the biggest expenses for his business. Eager to reduce costs and become more energy efficient, this farmer signed up to be a part of the ‘Energy Efficiency Gains for Australian Irrigators’ project. The EEGAI project looked at possible changes to this farmers' irrigation practice to increase his efficiency. This included increasing inflow rates to reduce the time taken to irrigate the field.

Case Study 6. Understanding the Duty Requirements of your Pump

John and Phil Deguara irrigate sugarcane at Brightly near Eton in the Mackay region. Their property was selected as a demonstration site for a pump energy assessment under the “Energy Efficiency Gains for Australian Irrigators” project.

The focus of the demonstration was a sugarcane block that had recently been irrigated using a high pressure soft hose travelling irrigator (Model 160 Southern Cross) to a Reinke hose drag lateral move irrigator that irrigates approximately 60 Ha. While the travelling irrigator is currently only used to irrigate a portion of the block, it is being maintained as the backup if the lateral move were to break down. The water is supplied by the Kinchant Dam supply channel with some tail water collection into an onsite dam with the potential for reuse.