Energy Savers
Southern Downs

Stanthorpe Horticulture Farm

Implemented
25
Energy Savings
4.8
Savings
1,670
Industry
Horticulture
Product
Tomatoes and capsicums
Irrigation
Drip
Pumps
Centrifugal
Technology
Irrigation, Variable Speed Control, Tariffs
Capital Cost
$43,400

Summary

A drought-affected horticulture farm located in Stanthorpe could still benefit from saving both time and money from recommendations in a recent energy savers audit. The audit recommended installing Variable Speed Drives (VSDs) on the irrigation pumps and a solar PV system to offset the energy consumption from the grid by 50%.

The farmer has implemented the irrigation upgrades with potential energy savings of 25%, costs savings of 21%, and emission reductions of 4.8 tCO2-e per year. Savings will be updated when the measurement and verification process is complete.

The farm, near Stanthorpeproduces tomatoes and capsicums and is irrigated year-round depending on rainfall. Water is supplied from an on-site irrigation dam and is replenished from rainfall and the nearby creek. It has been severely affected by the recent drought. The site is undulating and has different sized blocks and so has complex irrigation needs. 

It is a small site consuming approximately 23,000 kWh per year at a cost of $7,800. The current production is approximately 1,250 tonnes per year. 

The infrastructure contributing to the energy consumption onsite consists of:

  • Three 15kW centrifugal pumps.
  • A shed with lighting and electrical equipment.

A recent energy audit showed how improving the current systems can lead to energy and cost savings. The recommendations explored in the audit included:

  • Installation of 3 x 15kW Variable Speed Drives to compensate for paddock top, including a soil moisture monitoring system to manage more efficiently the limited water at the site.
  • Replacing irrigation suction pipes moving from 75mm to 150mm PVC to reduce friction losses.
  • Installation of a 10kW solar system at one of the pumps.
  • Tariff Change-  moving from obsolete T65 to T20 Time of Use (TOU).

Table 1. Energy and cost savings from audit recommendations

Recommendations Annual Energy Savings (kWh) Annual Costs Savings ($) Emission Savings (tCO2-e) Capital Cost ($) Payback Period (Years)
3x15kW VSDs and soil moisture monitoring 4,600 1,300 3.7 38,400 29
Pipe replacement 1,300 370 1.1 5,000 13.5
10kW Solar System 4,200 2,200 3.4 15,000 7
Total 10,100 3,870 8.2 58,400 16.5

 

The grower has proceeded with the installation of the VSDs, soil moisture monitoring system and upgrading of the pipework, while solar will be considered in the future. Actual savings will be updated once the measurement and verification process is complete.

By installing the recommendations in the audit, the business is expected to reduce energy consumption by 25% and costs by 21%, with carbon emission savings of 4.8 tCO2-e per year.

Table 2. Pre and post audit energy consumption, costs, and energy productivity savings

Metric Pre-Audit Post-Audit Reduction (%)
Energy Consumption (kWh) 23,000 17,100 25
Cost ($) 7,800 6,130 21
Energy Productivity (kWh/tonne) 18.4 13.8 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 on site.  

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 by the Queensland Farmers Federation with support and funding from the Queensland Department of Energy and Public Works. 

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