Caboolture Horticulture Farm
Energy Savings: 39% | Cost Savings: $26,000 | Capital Cost: $210,000 | CO2 Savings: 97.1 | Project Status: proposed
Industry:
Horticulture
Location:
South-East
Pump Type:
Not applicable
Irrigation Type:
Not applicable
Technology:
Irrigation and Pumps, Refrigeration, Solar Power and Renewables, Variable Speed Drives
The farm, near Caboolture, produces strawberries and is irrigated for 9 months of the year depending on rainfall. Water is supplied from on-site irrigation dams which are replenished from rainfall. The farm has two main pump houses which irrigate two farming areas, and a large packing shed with cold rooms.
It is a large site consuming 310,000kWh of electricity per year at a cost of $95,000, and harvests 1,200T of strawberries over 30 hectares.
The infrastructure contributing to the energy consumption onsite consists of:
- A pump shed containing 3 x 37kW pumps in series that serves one area of the farm.
- A pump shed containing 3 x 55kW pumps in series that serves a different area.
- 4 large cold rooms with separate condensers, around 20 years old.
- Large packing shed with sorting equipment.
- Workers accommodation.
A recent energy audit showed how improving the current systems can lead to energy and cost savings. The energy audit recommended the following changes to improve efficiency and reduce costs:
- Installation of 3 solar PV systems, a 30kW system for the packing shed, a 20kW ground-mounted solar system for the smaller pump shed, and a 30kW ground-mounted solar system for the large pump shed.
- Replace the 4 cold room condensers with new units with Variable Speed Drives (VSD) on the compressor and the condenser fan.
An additional recommendation was to upgrade the air conditioning system in workers accommodation with a single VRF (variable refrigerant flow) unit with multiple heads, which has been found to be approximately 25% more efficient than the current split systems.
Table 1. Energy and cost savings from audit recommendations
| Recommendations | Annual Energy Savings (kWh) | Annual Cost Savings ($) | Emission Savings (tCO2-e) | Capital Cost ($) | Payback Period (years) |
| 30kW Solar on packing shed | 40,000 | 6,310 | 32.4 | 45,000 | 7.1 |
| 20kW solar on pump shed | 17,300 | 3,440 | 14 | 34,000 | 9.9 |
| 30kW solar on pump | 35,000 | 10,500 | 28.4 | 51,000 | 4.9 |
| Replace condensing units on cold rooms | 27,500 | 5,750 | 22.3 | 80,000 | 14 |
| Total | 119,800 | 26,000 | 97.1 | 210,000 | 9 |
Following the audit report recommendations, the grower will assess the options and may implement them in the future.
By installing the recommendations in the audit, the business could reduce energy consumption by 39% and costs by 27%, with carbon emission savings of 97.1 tCO2-e per year.
Table 2. Pre and post audit energy consumption, costs, and energy productivity savings
| Metric | Pre-Audit | Post-Audit | Reduction (%) |
| Energy Consumption (kWh) | 310,000 | 190,200 | 39 |
| Cost ($) | 95,000 | 69,000 | 27 |
| Energy Productivity (kWh/tonne) | 260 | 158 | 39 |
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.
The Energy Savers Plus Extension Program was delivered by the Queensland Farmers' Federation with support and funding from the Queensland Department of Energy and Public Works.
