Energy Savers
Mundubbera

Mundubbera Citrus Farm

Implemented
7
Actual Energy Savings
Industry
Horticulture
Location
Mundubbera
Pumps
Centrifugal
Solution
Upgrade booster pump, solar system installation

Farm Profile

The farm, near Mundubbera, produces a variety of citrus and mangoes and is irrigated year-round depending on rainfall. Water is supplied from an on-site irrigation dam and replenished from the river.

It is a large site consuming 1,800 MWh per year and harvests 17,000 bins per year of fruit over 170ha. Their current energy benchmarking is approximately 240kWh/tonne of fruit produced.

The site energy consumption consists of:

  • A number of large pumps that serve different areas of the farm. Some pump direct from the river and some from the irrigation dam.
  • A large pump that pumps from the river to an irrigation dam which also irrigates some plots, responsible for approximately 30% of site energy use and is the highest user of energy
  • A booster pump that pumped from the irrigation dam to the plots that could not be reached by the other pump, so double pumping occurred. This pump is approximately 3% of the site use and was chosen to be analysed to try and reduce the double pumping and some demand charges
  • A packing shed

An audit of site energy consumption evaluated:

  • Tariff analysis
  • Installation of a solar PV system
  • Upgrading the booster pump
  • Installing smart water metering for irrigation scheduling

Of the energy saving opportunities evaluated, three initiatives were identified. A potential energy saving of 7% of the site total, and approximately $90,000 p.a. with an average payback period of 5.5 years.

A tariff analysis was completed on the sites tariffs and it was found that there were savings of approximately $11,000 per year by changing the tariff on the largest pump. The pump was on Tariff 66, which is an irrigation tariff being phased out in July 2021. It was recommended to change to Tariff 50 which is a large Time of Use tariff.

The audit report recommendations included installing a new booster pump. A new booster pump would partially remove the need for the double pumping from the dam. A variety of duty points were tested and it was determined that a new, smaller pump (160kW to 75kW) would have returned a payback period of just over four years. A Variable Speed Drive (VSD) was also recommended to better control the pump flow rates and pump performance.

Other recommendations included installing a ground mounted solar system at the site of the large pump of 39kW, which resulted in a payback period of approximately 6 years. Changing the irrigation scheduling to match the solar output allowed for higher utilisation of the energy generated. Smart water meters were also recommended to better monitor volumes of water being double pumped and irrigation amounts.

Following the audit report recommendations, the grower proceeded with installation of the new booster pump, changing their tariffs and will install the solar in the future. Post implementation benchmarking is predicted at 223kWh/tonne of fruit produced.

Measurement and verification is to be completed on the pump and solar systems in the coming months.

Estimated results of energy conservation measures are summarised below:

Solution New Booster Pump 39kW Solar Installation
Est. Cost to implement $66,000 $64,000
Est. Energy Savings 28,700 kWh/p.a. 64,000 kWh/p.a.
Est. Operating cost saving $16,000 $10,000
Payback Period 4 years 6.4 years

 

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.