River Extraction Pumps

Overview

A large-scale agricultural enterprise in regional Queensland engaged energy specialists at Saturn Engineering Group to assess and improve the efficiency of their irrigation pumping systems. The business operates multiple river harvest pumps to irrigate their cotton and cattle farm, consuming significant electricity annually. The audit identified key opportunities to reduce costs, improve energy efficiency, and lower greenhouse gas emissions.

Challenge

The operation relied heavily on two river harvest pumps, a Flygt and China pump, collectively consuming over 445,000 kWh annually, leading to significant electricity costs under transitional tariff rates. These pumps also showed moderate efficiency levels, with one operating at 66.3% and the other at 70.2%. The China pump was operating outside the pump manufacturers recommendation. Rising energy costs and the need for sustainable practices underscored the importance of finding long-term energy solutions.

Pump Assessment Findings

The energy audit included a detailed evaluation of the two primary irrigation pumps. The findings highlighted both strengths and areas for improvement in their performance:

  • Efficiency Levels: The Flygt pump achieved an efficiency of 66.3% when transferring water into the irrigation channel and 65.2% when lifting water into the storage dam. While these levels are moderate, there was clear potential for optimisation.

  • Energy Consumption: Over a 12-month period, the Flygt pump consumed 234,456 kWh of electricity. This represented a significant operational cost, particularly under the transitional tariff structure.

  • Proposed Upgrades: The replacement of the existing 600mm steel discharge pipe with an 800mm poly pipe. This measure would reduce friction losses, improve water flow rates by 9.3%, and save approximately 23,300kWh annually.
  • Efficiency Levels: The China pump demonstrated slightly better performance, with an efficiency of 70.2% when transferring water into the irrigation channel. This result indicated that the pump was operating effectively but still had room for improvement

  • Energy Consumption: During the same period, the China pump consumed 211,286 kWh of electricity, accounting for a substantial portion of the farm’s overall energy usage.

  • Proposed Upgrades: Matching the pump to the task by increasing the size of the China pump. Water flow rate was increased by 31.1%. Increasing the water flow rate also increased the friction losses. Installing a larger diameter pipe reduced friction losses and improved pump performance achieving a pump efficiency of 85.1%. During periods of high river water levels pump efficiency would improve further up to 91.0% with an additional increase in water flow rate due to the lower total dynamic head. Electricity consumption was reduced by 42,100kWh saving 20.0%.

Common Findings

Both pumps demonstrated stable operational patterns, but the audit noted inefficiencies due to friction losses in the existing discharge pipes and a pump not matched to the task.
The energy assessments suggested that improved infrastructure, such as upgraded pipes and pumps, would not only enhance pump performance but also yield substantial cost savings and environmental benefits. Performance Comparison and Benchmarking
The audit compared Pump 1 and Pump 2 with manufacturer benchmarks to evaluate their current performance levels. Both pumps were found to operate within acceptable efficiency ranges, though they fell short of optimal performance. The proposed measures were tailored to address these gaps and deliver improved operational results.

Conclusion

This case highlights the value of targeted energy efficiency measures in agricultural operations. Through strategic investments in infrastructure upgrades, the farm achieved substantial cost savings and environmental benefits. This project serves as a model for other agricultural businesses seeking to balance economic and environmental sustainability.

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.