Energy Savers
Bundaberg

Bundaberg Cane Farm

Proposed
86
Proposed Energy Savings
Industry
Sugar Cane
Location
Bundaberg
Pump
Centrifugal and Booster
Irrigation
High pressure gun, medium pressure boom and low-pressure furrow
Solution
Pump upgrade

Farm Profile

A 46ha sugar cane farm in the Bundaberg region could benefit from a recent Energy Savers audit. The audit considered energy consumption, hydraulic losses, and crop management. The audit recommended a pump upgrade and changing the farm’s irrigation design.

The site consists of a river pump and booster pump on separate NIMIs and irrigated using high pressure gun, medium pressure boom and low-pressure furrow. The fixed speed pumps operate from a standard star delta control and are poorly matched according to the pump duty and operating condition when running together. Current water use is roughly 160mm per year yielding about 40tc/ha, as most of the cane is grown with rainfall.

Total energy consumption recorded from the two pumps was 49,280 kWh costing $19,943, with emissions of 45.3 t/CO2-e per annum. The farm energy audit recommended changes to the current pumping and irrigation system to improve efficiency, this included works on:

  • The 30kW River Pump, 24,032kWh, $8,913 – Upgrade the pump including suction and discharge works, and mainline pipeline upgrade.
  • The 45kW Booster Pump, 25,248kWh, $11,030 – Upgrade the pump and install a Variable Speed Drive (VSD), including suction and discharge works. Install a 28ha centre pivot and 7kW solar system.

Recommendations in the Energy Audit

Recommendation Energy savings (kWh) Cost Savings ($) Payback Period (Years) Emissions (t/CO2-e)
30kW Pump- upgrade works 9,936 2,670 17 9.1
Mainline Upgrade 2,401 645 42.6 2.2
45kW Pump- upgrade works 5,400 1,446 8 4.9
28ha centre pivot 25,128 6,730 21 23.1
7kW solar system 7,091 1,899 5.9 6.5
Total 49,956 13,390 18.9 45.8

 

Based on the current volume of irrigation, the efficiency recommendations do not reflect the true economic value of the upgrades. The current system is under-irrigating resulting in poor crop yields of 40tc/ha. An increase from the current use of 160mm of effective rainfall, to 450mm to 500mm of irrigation is ideal and best for growing sugar cane in the region. Based on the sugar mill average for the soil media conditions, a potential crop yield of 100tc/ha and profit increase would result if the irrigation system is upgraded.

Net production improvements from the application of more water

System Yield (@$35/t) Application Uniformity (%) Water and Labour Cost ($) Net production ($)
Current 5ML 40 65 7,632 64,092
All upgrades 10ML 105 90  

14,200

 

152,075

Boom 10ML 85 75

With the use of the new centre pivot, improvements to the system capacity will meet daily crop water demand, from the improvement in irrigation application and efficiency. The increase in crop yield from 40tc/ha to 100tc/ha will provide a net benefit of $87,983, or 137 per cent in net primary production per annum, and reduce the payback to just 2.65 years.

Pre and Post Audit Metrics – excludes the 7kW solar system

Metric Pre-Audit Post Audit Reduction (%)
Energy Consumption (kWh) 49,280 6,415 86
Energy Costs ($) 19,943 8,452 57
Emissions (t/CO2e) 45.3 6 86

 

Production increase aside, energy consumption could be reduced 86 per cent and costs by 57 per cent after implementing pumping and irrigation upgrades. Should the site install the 7kW solar system an additional 7,091kWh could be generated on site, offsetting the pumps energy use. With an additional 6.5t/CO2-e removed per annum the site could become Carbon neutral.

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.