The Farm

The Chicken Rearing Farm consumed 218,990 kWh in the year before the audit at a cost of $31,974. In addition to that, the facility also consumed 71,602 litres of LPG at a cost of $61,832. The combined greenhouse emissions from the facility were estimated to be 302.5 tonnes of carbon dioxide equivalent. The site operates 24/7 during the 20 week rearing cycles.

The farm’s is in South-east Queensland so the farm is not an Ergon customer. Electricity is split in three different tariffs: 7200 LV Demand Time-of-use, 8100 Large demand and 8300 Small demand.

The energy-use breakdown at Figure 1 shows that 81% of the farm’s electricity consumption is ventilation with lighting being the next highest user at 13%.

Figure 1: Energy Use Breakdown

Figure 2: Ventilation fans in operation, but the shutters have not fully opened.

Energy management opportunities

The audit identified several opportunities that can be broken down between renewable energy installations and energy efficiency. It needs to be noted that the electricity rate at Laidley North is remarkably low inclusive of both contracted retail rates, and more site-specific network charges.

Key Recommendations:

The main recommendations for the audit are as follows:

Optimise Ventilation System Airflow: this measure consists of regular maintenance to remove dirt, dust and grime from all parts of the ventilation fans including the blades, motors and shutters. Dirt can reduce the size of the aperture, cause turbulent flow and in some cases, it was observed to be restricting the movement of baffles and shutters, restricting air flow by between 20 – 40%.

Belt Tensioning, Cleaning and Replacement. The audit recommended more frequent checks and adjustments to the ventilation fan belts, to ensure suitable tension, and replace when necessary. It is estimated that the fans can run up to 10% more efficiently when maintained, compared to when belts are loose and worn.

Although the above two actions may take time, they will reduce energy consumption and maintain the ventilation systems ability to achieve set temperatures.

The recommended prioritisation of the identified opportunities is so:

1. Undertake lighting upgrade in Shed 6 (works already approved for implementation).
2. Review ventilation fan operation and develop a maintenance regime to address identified issues.
3. Analyse options for electrical sub-metering and determine how this can support the optimisation of ventilation.
4. Review solar power opportunity.
5. Undertake a more detailed feasibility assessment for VSD control on the ventilation fans.

Electrical sub-metering, the audit considered that submetering would improve the visibility of electricity consumption to allow informed decision making. An electrical sub metering system would include a dashboard screen for the farm manager so that they could monitor electricity consumption of the different sheds or systems in real time. If the sheds are metered separately, the consumption of sheds can be compared to ensure they are operating efficiently. Similarly, metering can be used to check that systems are operating as expected, such as, for example that heating and fan systems are not operating together, or that lights are switching on and off as expected.

Summary of recommendations:

The cost benefit analysis of the recommendations from the audit have been summarised in the table below:

* Lighting upgrade costs have been estimated based upon standard lighting.

Energy Audits

The farm had a Type 3 energy audit as a participant in the QBEST Ag program.

For more information about Choosing Solar Systems, see the Ag Energy Hub Solar Article HERE.

The program was delivered by the Queensland Farmers’ Federation and funded by the Queensland Government.