Pump Refurbishment to Supply Centre Pivots

Overview

A cotton farming enterprise in Central Queensland participated in an energy audit to enhance irrigation efficiency and reduce operational costs. The audit focused on two pumps a main supply pump and a slightly smaller boost pump used to irrigate crops via two centre pivots. This study highlights opportunities to improve energy efficiency through equipment upgrades and renewable energy integration.

Challenge

The farm relied on two Southern Cross pumps to irrigate approximately 42 hectares under two centre pivots. One pump was required to irrigate one centre pivot. To irrigate through both centre pivots at the same time required the use of the second boost pump These pumps had shown signs of inefficiency, consuming nearly 40,000 kWh annually at a cost exceeding $11,500. Operational data revealed that both pumps operated below optimal performance levels, with significant wear affecting efficiency. Rising energy costs further underscored the need for intervention.

Findings

The audit identified that the main pump achieved an efficiency of 64.0%, while the smaller boost pump performed slightly better at 66.5% when operating with the main pump. It was fount the boost pump improved in efficiency when used with the main pump but was slightly less efficient when operated by itself. The reverse would occur for the main pump, efficiency would decline when used with the boost pump. Their operation revealed inefficiencies, highlighting the need for refurbishment or replacement. Additionally, the energy audit demonstrated the potential for solar power to offset electricity consumption significantly.

Proposed Solutions

Refurbishing both pumps, including replacing impellers, shafts, and bearings, was estimated at $2,900, promising a 13% reduction in energy consumption saving 5,208 kWh annually. Replacing the pumps would cost approximately $15,000 but offered similar savings, with a longer payback period. Refurbishment was recommended as a cost-effective option with a payback period of 2.1 years and an ROI of 48.3%.

A 30kW solar array was proposed to offset electricity use. This system, with a capital cost of $29,620 (after small-scale technology certificates), would reduce energy consumption by 25,495 kWh annually, equivalent to 63.8% of the pump station’s total usage.

Implementation Plan

The recommended measures included refurbishing the pumps to restore performance closer to manufacturer specifications. Simultaneously, installing the solar array would generate renewable energy to meet most of the farm’s irrigation demands. A proposed measurement and verification plan was also developed to track performance improvements and energy savings over time.

Outcomes

By implementing these measures, the farm could

Conclusion

This project demonstrates how targeted energy efficiency initiatives can transform agricultural operations. Through modest investments in equipment refurbishment and renewable energy, the farm achieved significant cost and environmental benefits. These outcomes highlight the potential for other agricultural businesses to adopt similar strategies to improve sustainability and profitability.

Key Takeaway

By tailoring energy solutions to the specific needs of each pump site, farms can achieve significant cost and energy savings. Saturn Engineering Group remains committed to delivering innovative, practical strategies to support agricultural businesses in their transition to sustainable operations.