Of the energy-saving opportunities evaluated, three initiatives were identified with potential energy savings of 38%, a combined payback period of 8.4 years and carbon savings of 37 tCO2-e per year.
Energy Savers
Summary
The farm, near Mareeba, produces tropical fruits and is irrigated year-round depending on rainfall. Water is supplied from the nearby river connected to the Tinaroo irrigation scheme.
It is a large site consuming 120,000kWh at a cost of $31,000. The farm is in the process of establishing new orchards and planning future directions.
The site energy consumption consist of:
- An old, large 75kW centrifugal pump.
- A smaller 50kW centrifugal pump.
- Two cold rooms, one is fast–cool.
- A large packing shed with sorting equipment.
A recent energy audit showed how improving the current systems can lead to energy and cost savings by investing $115,000, the recommendations explored in the audit included:
- Tariff analysis.
- Replacing the large pump.
- The potential to install a solar PV system to offset grid electricity.
Table 1. Energy savings identified from audit recommendations
| Recommendation | Energy savings (kWh) | Cost Savings ($) | Emission Savings (tCO2-e) | Payback Period (Years) | Cost to Implement ($) |
| Upgrade 75kW pump | 20,000 | 5,600 | 16 | 8 | 45,000 |
| Install 20kW solar at packing shed | 14,000 | 4,200 | 11.2 | 8.3 | 35,000 |
| Install 20kW solar at big pump | 12,000 | 3,900 | 9.8 | 9 | 35,000 |
| Total | 46,000 | 13,700 | 37 | 8.4 | 115,000 |
A tariff analysis was completed on the sites tariffs and it was found that there were savings of approximately $2,500 per year by changing the tariff at the packing shed. The farm was on the transitional Time of Use tariff 62, which is being phased out in July 2021. It was recommended to change to Tariff 20, which is a small business flat rate tariff.
The audit report recommended upgrading the 75kW pump. The pump was tested and found to be operating at an efficiency of 58-60%, if the pump were upgraded to an efficiency of at least 75% and a motor efficiency of 92%, there would be a payback period of 8 years. Other recommendations included installing high quality 20kW solar systems on the packing shed and at the big pump. By installing these systems it would be possible to achieve a payback period of 8 and 9 years respectively.
By installing all the recommendations in the audit, the business could reduce energy consumption by 38%, and costs by 44%, with carbon emission savings of 37 tCO2–e per year.
Table 2. Pre and post audit energy consumption and costs.
| Audit Metric | Pre-Audit | Post-Audit | Reduction (%) |
| Energy Consumption (kWh) | 120,000 | 74,000 | 38 |
| Energy Costs ($) | 31,000 | 17,300 | 44 |
–
Following the audit report recommendations, the grower did not proceed with any of the suggestions due to other business pressures.
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.
See our range of agricultural energy efficiency case studies HERE and Subscribe to our bi-monthly energy e-news HERE
If you have any energy efficiency related questions for the team get in touch at energysavers@qff.org.au.
The Energy Savers Plus Extension Program is delivered in by the Queensland Farmers Federation with support and funding from the Queensland Department of Energy and Public Works.
