Boosting Irrigation Efficiency on a Citrus Farm

Overview

A large commercial citrus farm in Queensland faced rising energy costs and inefficiencies in its irrigation system. Saturn Engineering Group conducted a detailed Type 3 Energy Audit on the farm’s pump station, identifying significant energy management opportunities to reduce costs and emissions while improving system performance.

Challenge

The farm operates two irrigation pumps in series to maintain the required pressure and water flow rate for 37,945 citrus trees spread across 104 hectares. From December 2022 to November 2023, the pumps consumed 357,668.5 kWh of electricity, costing over $119,000. Pump efficiency was low across both pumps, ranging between 44.2 and 62.2%, with energy usage indicators ranging from 4.63 – 6.52kWh/ML/m head, revealing inefficiencies that inflated costs and carbon emissions. A simple Tariff analysis identified the pump station was on the wrong Tariff. Changing from the current Tariff 45 to Tariff 44 saved the farmer $9,560 annually, 7.4% cost reduction.

Proposed Solutions

The audit recommended two key upgrades to address these challenges:
Name Pump Station Upgrade with Variable Speed Drive (VSD) Installation Installation of a 100kW Solar System
Estimated Cost
$152,752
$104,648.50
Predicted Savings
92,018.5 kWh annually (26% reduction)
122,817.9 kWh annually (34% reduction)
Additional Benefits
Improved pump efficiency and reduced operational demand.
Reduced reliance on grid electricity and offset emissions.
Financial Impact
Annual cost savings of $19,737.78 with a 7.7-year payback period and a 12.9% return on investment.
Annual cost savings of $24,264.88 with a 4.3-year payback period and a 23.2% return on investment.

Implementation

The pump station upgrade involved redesigning the irrigation shifts and replacing the two existing pumps with a single pump model better suited to the farm’s specific needs. The addition of a VSD enabled the pumps to adjust speeds based on demand, optimising energy use. The solar system was designed to maximise on-site energy consumption and eliminate dependence on peak electricity tariffs.

Results

Conclusion

The upgrades provided a transformative improvement in irrigation system efficiency, significantly lowering operational costs and reducing the farm’s environmental footprint. These changes also improved the reliability and performance of the pumps, ensuring consistent irrigation for the farm’s citrus production.

Key Takeaway

This case highlights the importance of tailored energy solutions and renewable energy integration in agricultural operations. By combining advanced technology with system optimisation, farms can achieve substantial cost savings and sustainability goals. Saturn Engineering Group remains committed to helping agricultural businesses implement effective energy management practices.