A sugarcane and future macadamia farming enterprise located in Bundaberg could benefit from a recent Energy Savers Audit. Farming requires constant decision making to maximise production and profit. Often irrigation systems are out of date and are in need of replacement to incorporate new technologies and updated knowledge.
The total area of cropping lands consists of 82 ha and is divided into three sectors that are serviced by four pumps, whit only three being included in this proposal. The current pumping systems service two sections of the farm through interconnecting underground mainline. These sections are mostly utilised for sugarcane production while an area to the north of the sugarcane fields is being developed as a macadamia nut orchard. Energy consumption from the pump site showed that a total 61,387kWh at a cost of $21,228 was used during the 2018-2019 period.
Pump site one services 35 ha of sugarcane with travelling gun and gravity feed furrow methods. While the incoming pressure is adequate to irrigate much of this area through gravity feed furrow irrigation, when supplying the travelling gun, a pressure management gate valve is used on the distribution side of the pump to enable the restricted operation to maintain pressure. Pump two is only used occasionally to support the main irrigation system and to irrigate the developing macadamia nut orchard. The site has historically been connected to tariff 66 which includes a fixed monthly charge based on motor size and when use is limited this charge can present a significant portion of the account. Finally, pump three services 20 ha of sugarcane with low pressure hand shift sprinklers and trickle irrigation. It has a low capacity motor that draws an average of 10 kW/hr delivering irrigation at 115 kWh per ML of water pumped. None of the pumps is currently connected to tariff 33.
A recent energy audit showed how improving the current systems can lead to energy and cost savings. The recommendations explored in the audit included:
- The replacement of pump, motor and installation of VFD at pump one
- Installation of Solar PV at pump one
- Conversion to Tariff 33 at all pumps
Table 1. Energy savings from audit recommendations
||Annual Energy Savings (kWh)
||Annual Cost Savings ($)
||Emission Savings (tCO2-e)
||Capital Cost ($)
||Payback Period (years)
|Pump upgrade and install VFD
|Change to Tariff 33
The replacement of pump, motor and the installation of VSD at pump one will lead to a significant reduction in energy use and cost and provide the potential for sustainability of current levels of high productivity. Energy demand will decline as the VSD will manage factors related to incoming water delivery pressure fluctuation. The addition of a Solar PV system to the improved pumping system will further reduce grid energy demand for pumping and provide an additional income stream from energy export. With all pumps (1, 2 and 3) connected to Tariff 33 and water use similar to that required for the 2019 crop, operating cost at pump one when combined with pumps two ($962) and three ($2,348) will result in an annual cost of $4,560. This will lower the annual estimated cost of irrigation for each tonne of cane produced to $0.56/tc.
By installing the recommendations in the audit, the business could reduce energy consumption for pumping by 56% and costs by 98%, including productivity gains, with carbon emission savings of 27.3 tCO2-e per year, which will enhance the profitability and productivity of the farm.
Table 2. Pre and post audit energy consumption, costs and energy productivity savings
|Energy Consumption (kWh)
|Energy Productivity (kWh/ha)
An energy audit is a good investment
An energy audit is a great first step in moving a business towards a more efficient future by reducing energy use, costs and carbon emissions onsite.
An energy auditor will review your past energy bills, your equipment and the way your business operates. They’ll show you where you’re using excess energy and explain what you can do about it. Find out about what’s involved in an energy audit HERE.
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If you have any energy efficiency related questions for the team get in touch at firstname.lastname@example.org.
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.