Energy Savers
Darling Downs

Western Downs Cattle Farm

Energy Savings
Beef and Cattle
Solar pumping, Energy storage
Capital Cost

Farm Profile

This Darling Downs cattle property finishes cattle using supplementary grain and forage crops. The farm includes a number of stock watering systems, both solar and diesel as well as a feed mill, cattle press and houses.

This case study will focus on the assessment of options to reduce diesel consumption at one pump with the addition of a solar pump and either diesel or battery backup.

Stock water is pumped to a header tank by a 3.7kW three-phase pump powered by a diesel generator for 12-14 hours each night. Although the generator does have a timer and input control, for ease of use, it is filled each night with 20L of diesel and run until it is out of fuel. The pump pushes approximately 2m3/hr and due to iron bacteria in the water, needs to be replaced approximately every 2-3 years.

The audit has made a comparison of the costs and savings of solar pumping which include the installation of a new Lorentz solar pump at a cost of $15,000 and either:

  1. Using the existing diesel generator for backup; or
  2. Removing the diesel generator and replacing with batteries.

Assuming the solar runs for eight hours per day with backup supplied for four hours

  1. Using Existing Generator:
    • Reduce the current fuel use by 2/3rd saving 4,870 L, corresponding to $5,990 p.a. from the installation of the solar pump.
    • Assumed generator maintenance cost of $950 p.a.
    • Payback 2.16yrs, 46% ROI with cost savings of $5,990 p.a.
  2. Replace existing diesel generator with solar pump and battery backup:
    • Requires an added cost of $12,500 to install battery back-up system.
    • Cost saving amounts to all fuel and servicing of the generator $9,935 p.a.
    • Payback 2.7yrs, 36% ROI.
Solution Add a Solar Pump and:
Use Existing Generator Replace Generator with battery backup
Annual Energy Saving (Litres Diesel) 4,870 7,305
Estimated Cost to Implement Solar Pump: $15,000 Solar Pump: $15,000

Battery: $12,500

Annual Cost Savings $5,990 $9,935
Payback (years) 2.2 years 2.7 years
Carbon Emissions Reduction (t CO2-e) 14.2 21.3


By replacing the generator with battery backup is possible to offset 100% of the farm diesel consumption with 110% associated cost savings, as well as the additional benefit of not having to replace the equipment every 2-3 years.

This case study concentrated on the one irrigation system although the energy audit showed additional savings that could be made onsite including:

  • Install Variable Speed Drive (VSD) on a 3-phase feed mill motor
  • General Motor maintenance
  • Installing a 17kW Solar System
  • Install bore pump control

The audit showed on average the farm consumes over 55,000kWh p.a. at a cost of $16,900 p.a. This equates to a total energy cost per head of $4.30. If all recommendations are implemented the energy cost per head would be reduced to $0.86.

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.

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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.