Energy Savers
Southern Downs

Stanthorpe Horticulture Farm

Proposed
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 by 50%. The farmer has implemented the irrigation upgrades with energy savings of 25%, reducing costs of $1,670 and emission by 4.8 tCO2-e per year.

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 some 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  three 15kW Variable Speed Drives to compensate for paddock top, including a soil moisture monitoring system to more efficiently manage 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 in one of the pumps NMIs
  • 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 future upgrades. Measurement and verification will be completed on the site in the coming months.

By installing the recommendations in the audit, the business could have reduced 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 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 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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