McCain Foods Ballarat Facility

Description

McCain Foods’ Ballarat food processing plant is home to a major behind-the-meter renewable energy project that combines large-scale solar with a biogas cogeneration system. 

At the site, Optimal Group Australia was engaged to design and deliver the cogeneration component, using biogas produced on site to generate electricity and recover useful thermal energy for steam production. The project progressed through staged installation, open-cycle commissioning and final turbine exhaust gas recovery commissioning, with open-cycle handover completed in late 2022 and final TEG tuning and handover to McCain operations completed in April 2025. The cogeneration plant is designed to use biogas from McCain’s existing covered anaerobic lagoon, as well as an anaerobic digester that will be completed in the future. 

The system being delivered is based on two (2) x Capstone C600S packages. Each package includes three (3) fully independent 200 kW Microturbines. At a combined 1,200 kW of power generation, the combined packages are sized to utilise the maximum biogas production available. Capstone Microturbines can tolerate a large variation in biogas composition, making them an ideal choice for the changes in gas quality that occur with anaerobic digestion. In addition, each turbine can turn down (i.e., part load) or turn off based on response to gas volumes or power demand. Also, each of the 6 x 200 kW modules can be serviced while the remaining units continue to operate, providing power continuity at all times.

For McCain, the solution was developed to maximise the total energy efficiency of the biogas. To achieve this, Optimal developed a heat recovery solution using SAACKE’s range of cofired burner technology. Normally, a hot water or steam boiler takes ambient air into the burner, adding fuel to lift the air to the required temperature to generate steam or hot water. Saacke’s burner technology allows the burner to use both the turbine exhaust and fresh air as combustion air. Because the turbine exhaust is much hotter than ambient air (>280°C), the burner needs to add less fuel (natural gas in this case) to produce the same amount of steam. With 18% oxygen, the turbine exhaust can be used directly for combustion, or mixed with fresh air where not all turbines are operating.

In the case of Capstone Microturbines, there are no cooling or lubrication circuits, so almost all of the energy not converted to electricity is available as exhaust heat. Using the exhaust heat directly as combustion air harnesses 100% of the available thermal energy, which results in total system fuel efficiency above 90%.

This high-efficiency cogeneration installation reduces the CO2 emissions equal to the 7 MW of PV being developed, demonstrating the unique potential of biogas to reduce emissions for the food industry.