Optimising Energy Efficiency at a Queensland Piggery

Overview

A large piggery in Queensland, housing 2,800 pigs and producing 120 head per week, faced rising energy costs and inefficiencies across key processes, including ventilation, heating, and feed production. To address these challenges, a Type 2 Energy Audit was conducted by Saturn Engineering Group to identify opportunities for energy savings and emissions reductions. The audit evaluated energy consumption across the piggery’s operations and proposed targeted energy management opportunities (EMOs) to improve efficiency and reduce costs

Challenge

The piggery consumed over 200MWh of electricity in the 2023/24 financial year, with a cost over $75,000 on SAC Large Tariff 44. Key areas of energy consumption included ventilation fans, heat lamps, and a feed mill, with ventilation accounting for 45% of total energy use. The farm sought to reduce energy consumption and operating costs while maintaining production efficiency and piglet health.

Proposed Solutions

  • Replacing the existing 370W fans with more efficient 150W Fanquip single-phase fans was recommended. This upgrade would reduce electricity consumption by 47,700kWh annually, equating to savings of $10,000. The capital cost of $42,900 would result in a 4.3-year payback period and a 23.3% return on investment.
  • To optimise the operation of heat lamps, which are critical for piglet health, temperature control units were recommended. This measure would reduce electricity use by 5,200kWh annually, saving $1,070 at a cost of $4,000. The payback period was estimated at 3.7 years, with a 26.8% return on investment.
  • Installing an off-grid solar bore pump for stock water would offset 4,300kWh of grid electricity annually, saving $890.27. However, the high capital cost of $15,000 resulted in a 16.9-year payback period and a 5.9% return on investment, making this option less viable without additional incentives.
  • Conducting a Type 3 Energy Audit on the feed mill was proposed to evaluate the performance of its equipment, particularly the hammermill, which consumed 75.1% of the mill’s energy. This involves measuring analysing individual motor performance. Potential savings to upgrade the feed mill were estimated at 8,900kWh annually, valued at $2,100, were identified, but the long payback period of 9.4 years limited its immediate feasibility.
  • Upgrading the effluent pump to a more efficient 2.4kW model was recommended, reducing electricity use by 3,723.0 kWh and saving $765.86 annually. The capital cost of $5,518 would result in a 7.2- year payback period and a 13.9% return on investment.
  • Installing a 60kW solar system would reduce grid electricity consumption by 82,000 kWh, saving over $33,500 annually. This $75,000 investment would have a 2.2-year payback period and a 44.6% return on investment. Additionally, combined with ventilation fan upgrades, the farm could reduce consumption below 100MWh annually, enabling a switch to the lower-cost SAC Small Tariff 20.

Results

If all recommended EMOs were implemented, the farm would achieve:

Conclusion

The energy audit identified actionable steps to significantly reduce the piggery’s energy costs and carbon footprint. Implementing high-impact measures such as ventilation fan replacements and a 60kW solar system, alongside strategic upgrades to other systems, would provide immediate and long-term benefits.

Key Takeaway

This case demonstrates how targeted energy efficiency measures and renewable energy integration can transform agricultural operations, delivering cost savings and sustainability benefits. Saturn Engineering Group continues to support farms in achieving optimal energy management practices