Energy Savers
Darling Downs

Western Downs Cattle Farm

Proposed
100
Energy Savings
21.3
Savings
9,935
Industry
Beef and Cattle
Pumps
Bore
Technology
Solar pumping, Energy storage
Capital Cost
$27,500

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.

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.

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