New Zealand’s first large-scale food waste-to-bioenergy facility, the Reporoa Organics Processing facility, has revolutionised food waste handling. The facility is estimated to turn approximately 75,000 tonnes of organic waste from businesses and households across the North Island into sustainable renewable energy each year.
New Zealand’s first large-scale food waste-to-bioenergy facility, the Reporoa Organics Processing facility, has revolutionised food waste handling. The facility is estimated to turn approximately 75,000 tonnes of organic waste from businesses and households across the North Island into sustainable renewable energy each year.
The facility is owned by Ecogas, a joint venture between Pioneer Energy and Ecostock Supplies, and situated on land owned by Turners & Growers (T&G), a New Zealand fresh produce business. T&G is leasing the land to Ecogas and, in return, buying renewable electricity, heat and CO2 from Ecogas to power its tomato glasshouses 450 metres from the facility.
From food waste to sustainable renewable energy
The facility uses anaerobic digestion to produce biogas, which is used in a combined heat and power gas engine to generate renewable energy. The energy generated from this process is enough to annually power up the equivalent of around 2500 households in the region, produce clean bio-fertiliser for approximately 2000 hectares of local farmland, and provide renewable CO2 and heat to enhance the growth of tomatoes in T&G’s glasshouses.
AECOM brought together its process, mechanical, civil and electrical engineering specialists to design the heat transfer and CO2 systems at the Ecogas facility and the T&G glasshouses. This work includes the interconnecting supply and return hot water pipelines, biogas supply lines, CO2 cooling, custody transfer, and pumping systems. The hot water and CO2 are used as a priority before the existing hot water boilers, which were retained as a backup, are used.
At the Ecogas facility, the combined heat and power gas engine generates electricity from biogas for onsite use, and heat is produced as a by-product of this process. Following the completion of the gas upgrading facility in mid 2024, a portion of the raw biogas will be upgraded to biomethane and CO2. The CO2 will then be cooled and piped to the nearby T&G glasshouses during daylight hours to assist photosynthesis.
Cutting carbon and creating a circular economy
The facility is expected to significantly reduce the amount of food waste that goes to landfill each year from the North Island of New Zealand. The project highlights the benefits of a circular economy to reduce reliance on natural resources, reduce emissions and foster innovations towards a greener future.