From two years of data average energy consumption of total farm was 27,766kWh at a cost of $3,467 per annum. Recommendations in the audit to improve energy efficiency onsite included:
- Installation of a 5.7kW Solar PV system.
- Bore pump replacement.
- Replace the standalone diesel with an off-grid solar pump.
Table 1. Recommendations and Savings from the Energy Audit
||Cost to Implement ($)
||Energy Savings (kWh)
||Cost Savings ($)
|Installation of a 5.7kW Solar PV system
|Bore Pump Replacement
|Remove standalone diesel and replace with Solar PV pump
The replacement bore pump has been designed using the measured Flow (m3/hr) and Head (m) as tested. As this pump has been sized using the measured flow and head, the result is a smaller motor size with greater efficiency. A variable speed drive was not suitable in this case as Submersibles require longer cable lengths. In that case, a sine filter would be required to reduce the rate of Voltage change. Network distortion can also be a problem and to avoid this you would need a low harmonic VSD, which are more expensive. It is generally simpler to look for total pump replacement when looking at reducing energy consumption on a submersible pump.
The specification of the diesel motor shows fuel consumption of 1.88L/hr when operating at 100% and the cost of operation at $1.50/L. Based on current operational figures a significant saving of 53,849kWh and $8,352 in operating costs could be achieved. The energy audit identified total consumptions savings of 63,088kWh, cost savings of $10,804 with a potential reduction in emissions of 58t/CO2 per annum.
By replacing the bore pump with a capital cost of $3,814, is possible to achieve total energy savings of 2%, which corresponds to savings of 18% in the energy consumed by the bore pump, in line with kWh/ML reductions. As measurement and verification takes place the case study will be updated with actuals.
Table 2. Pre and Post Audit Metrics
|Energy Consumption (kwh)
|Energy Costs ($)
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 firstname.lastname@example.org.
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.