Energy Savers
Darling Downs

Western Downs Grains Farm

Energy Savings
Grains and Fodder
Solar Photovoltaic, Energy Storage, Lighting, Fan
Capital Cost

Farm Profile

The site produces and stores grain onsite using a variety of small single-phase motors driving silo aerators, and lift and conveyor systems, to supply fresh and stored grain in automated temperature-controlled silos.

Energy use on farms can contribute to large operating costs. Reductions in both energy and carbon dioxide emissions can be seen from implementation of quick wins recommended by an energy audit.

General motor maintenance with regular cleaning of the blades with compressed air can reduce excess demand. Energy efficiency is decreased when temperatures in a motor stator increase. The build-up of dust prevents the air cooling of the motor which leads to increased heat. This increase in heat reduces the life span of motors and as a result they need to be replaced prematurely.

Further older single-phase motors powered by phase shifting capacitors can burn out over time leading to poor power factors. Replacement of the capacitors at an average cost of $500 for a small motor can lead to a 0.5kVA demand reduction and a payback of 1-2 years,

Replacing metal halides with new LEDs can decrease start up current reducing demand and enable longer run times. LEDs have an increased life expectancy, run at lower temperatures and can decrease the number of lights required, due to being a superior source of light. Reductions in consumption and demand are commonly seen.

Solution Silos: Humidity Control and hardwired power supply General Maintenance Capacitor Replacement: Single Phase Motors Replace Metal Halide Lighting with LED TOTAL
Energy Savings kWh 3,612 0 1,872 5,484
Demand Savings kVA 0 2.76 1.1  1.8 5.66
Cost Savings $1,975 $375 $375  $588 $3,313
Estimated Cost to Implement $19,500 0 $480  $2,700 $22,680
Payback (years) 10 1.3 4.5 5.25
Carbon Emission Reductions (t CO2-e) 2.89  



0 1.5  4.39


Demand savings for a small electricity user may not directly reduce costs but may free up power capacity and reduce the risk of brownouts, particularly on farms that are serviced by Single Wire Earth Return (SWER) lines.

Two 10kW Solar PV options were considered, with and without a battery.  The Auditor noted that:

  • The above humidity control needs to be implemented to make the solar system viable
  • Export is unlikely to be possible from the site as it is serviced by a Single Wire Earth Return (SWER) line
  • The solar system will be split into two separate systems across the incoming two phases, making two systems of 5kW each.
  • The switchboard needs upgrading to accommodate the new solar and this is incorporated into the costs below
  • The savings below are based on the existing Obsolete Tariff 62 and the savings will decrease when the farm moves to a Standard Tariff 20 on 1 July 2021
Solution A.     2 x 5kW Battery-ready Solar Systems B.      2 x 5kW Solar Systems with 2 x 10kWh Batteries
Annual Energy Savings kWh 7,691 20,606
Demand Savings kVA Up to 10  Up to 10
Annual Cost Savings $2,076 $5,565
Estimated Cost to Implement $21,695 $41,195
Payback (years) 10 7.5
Carbon Emissions Reduction (t CO2-e) 5.6 16.48


Given the greatest savings and lowest payback period, solution B is recommended, which together with the above recommendations allows the farmer to achieve 91% total energy savings, 87% cost reductions and emission savings of 20.9 tCO2-e per year.

The audit also estimated cost savings of over $1200 per year by switching from the Obsolete Tariff 62 to Standard Business Tariff 20. It is recommended to reassess your current operating tariff every 12 months.

An energy audit is a good investment 

An energy audit is a great way for a business to cut costs and boost productivity. Find out about what’s involved in an energy audit 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

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.