The site has combined water access to up to 400ML of bore water and a 140ML dam and bore onsite which irrigates 40ha to supply fodder for the livestock. The pumps move water through a network of 100mm and 150mm pipes supplying the irrigators which consist of four homemade pivot irrigators (10ha), a boom irrigator (6ha) and flood irrigation (24ha).
The farm uses a total of 150,463 kWh per year at a cost of $34,178 using obsolete Tariff 66 which is due to expire in June 2021. From the energy cost of the irrigation system, the motor contributes 30%, the pump 25% and the irrigator 30%. As water is double pumped through the older pumps there is an opportunity to improve energy efficiency, reduce costs and increase production.
Table 1. Pre and post audit motor and pump findings.
|Pump and Motor Efficiency (%)
||Energy Consumption (kWh)
||Pump and Motor Efficiency (%)
||Energy Consumption (kWh)
The remaining 15% of energy use is contributed by static head and pipe and fittings, changes will further improve efficiency. A recent energy audit showed how improving the current irrigation systems can lead to energy and cost savings.
Replacing the 100mm PVC pipeline that runs from the dam to pivot with a 150mm PVC pipeline will reduce the friction losses over that 130m from 8m to 2m. With the reduction in friction losses, the site could potentially save 17,429kWh and $4,620 per annum. Further recommendations show that by replacing the 100mm pipe with 150mm from the creek pump to the dam, the friction loss will be reduced 1m, though this is not recommended due to the longer payback period.
Table 2. Costs and savings from audit recommendations.
||Energy Savings (kWh)
||Cost Savings ($)
||Emission Savings (t/CO2-e)
||Payback Period (Years)
||Capital Cost ($)
|Replace irrigation pump (bore)
|Replace bore pump
|Replace creek pump (bore)
|Upgrade pipeline from dam to pivot
|Replace pipeline from creek to dam
Implementation of all the recommendations could see a potential site consumption of 75,412kWh costing $14,288 per annum, with a 58% decrease despite the increase in cost from the new tariff.
The farmer proceeded with the installation of the new bore pumps. Actual savings will be updated once the measurement and verification process is complete.
Table 3. Pre and post audit energy and costs, and savings.
|Energy Consumption (kWh)
An energy audit is a good investment
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The Energy Savers Plus Extension Program is delivered by the Queensland Farmers Federation with support and funding from the Queensland Department of Energy and Public Works.