A recent energy audit showed how improving the current irrigation system can lead to energy and cost savings. The recommendations explored in the audit included refurbishment of 4 irrigation pumps and install Variable Speed Control in 5 pivot pumps.
Energy Savers
Summary
The farm grows sweet corn and mung bean crops at two sites in the Home Hill area located within 10km. Mechanical harvesting is conducted before produce is trucked to Bowen for processing and refrigeration.
Energy consumption on both farm sites is dominated by pumping and irrigation operations. Other energy consumption is for minor uses such as lighting, office air conditioning and compressed air. The annual energy consumption for the site is 1,218,000 kWh at a cost of $288,000.
The site energy consumption consist of:
- 11 centre pivots that irrigate a combined area of approximately 780ha.
- 15 pumps ranging between 15kW and 75 kW that supply river water to centre pivots via channel and underground piping system.
A recent energy audit showed how improving the current systems can lead to energy and cost savings by investing $102,747, the recommendations explored in the audit with payback periods under 3 years included:
- Refurbishment of 4 irrigation pumps operating at low efficiency.
- Install Variable Speed Drives (VSDs) to 5 pivot pumps.
Table 1. Energy savings from audit recommendations
| Recommendation | Energy savings (kWh) | Cost Savings ($) | Emission Savings (tCO2-e) | Payback Period (Years) | Cost to Implement ($) |
| 4 Irrigation pumps refurbishment | 92,476 | 23,445 | 75 | 0.6 | 13,750 |
| 55kW pivot pump Variable Speed Control | 51,902 | 14,117 | 42 | 1.2 | 16,825 |
| 55kW river pump Variable Speed Control | 49,254 | 13,791 | 40 | 1.3 | 18,508 |
| 45kW pivot pump Variable Speed Control | 40,814 | 11,510 | 33 | 1.4 | 16,159 |
| 45kW pivot pump Variable Speed Control | 35,251 | 9,588 | 31 | 1.7 | 16,159 |
| 75kW pivot pump Variable Speed Control | 34,796 | 9,743 | 28 | 2.2 | 21,346 |
| Total | 304,493 | 82,194 | 249 | 1.2 | 102,747 |
The energy audit also suggested a review of the tariff pricing structure for several site accounts with potential savings of $5,945 per annum.
By installing all the recommendations in the audit, the business could reduce energy consumption by 25%, and costs by 29%, with carbon emission savings of 249 tCO2–e per year.
Table 2. Pre and post audit energy consumption and costs.
| Audit Metric | Pre-Audit | Post-Audit | Reduction (%) |
| Energy Consumption (kWh) | 1,218,000 | 913,507 | 25 |
| Energy Costs ($) | 288,000 | 205,806 | 29 |
| Emission (tCO2-e) | 987 | 738 | 25 |
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.
