Have your say on options to reduce emissions from organic waste

Mapping local infrastructure gaps and opportunities could support more effective diversion of organic waste and targeted investment in resource recovery infrastructure. Mapping can provide a clear picture of where organic waste is generated, how it is managed, and where existing infrastructure is insufficient or absent. Infrastructure gaps can include a lack of local processing capacity or logistical barriers to transporting organic waste. Opportunities could include co locating facilities, expanding existing sites, sharing use of infrastructure across council boundaries, or clustering feedstocks to improve viability. 

In addition to helping guide future Waste Minimisation Fund investment, this work could improve collaboration between councils, businesses and the private sector. Improved information could support partnerships where several large businesses operate in the same area, or where multiple councils could combine feedstocks to achieve economies of scale and support viable composting, anaerobic digestion or other organic processing facilities.

This measure builds on work already underway by the Energy Efficiency and Conservation Authority (EECA) to undertake a national, region by region assessment of organic waste feedstocks across New Zealand. EECA’s assessment will provide independent evidence on the quantity, type and location of organic waste materials. It will also quantify potential waste to energy yields, including anaerobic digestion and biomethane production, while remaining agnostic as to how that energy is ultimately used. 

This targeted mapping of infrastructure gaps and opportunities would complement EECA’s work by considering how feedstock information could be applied to infrastructure planning. This, in turn, could support councils, businesses and potential investors across the waste system to undertake more coordinated decision-making. 

Case study: Ecogas – coordinated organic waste management in practice

Ecogas operates anaerobic digestion facilities in New Zealand that process mixed organic waste streams to produce biogas and digestate. The Reporoa organics processing facility near Rotorua, commissioned in 2022, integrates household food scraps, commercial and retail food waste, and dairy-derived organic materials into a single processing system. This approach recovers energy and nutrients by biologically treating organic waste that would otherwise be disposed of to landfill.

The Reporoa facility provides a practical example of how cross sector coordination can improve resource-efficiency outcomes from organic waste. Kerbside food scraps and commercial food waste collected in the Auckland area are consolidated and transported to the facility using otherwise empty return-freight journeys, making existing transport more efficient. 

The biogas produced on site is used to generate energy for the facility and renewable gas to inject into the national gas network. Biogenic carbon dioxide and heat recovered in the process are supplied to a neighbouring tomato glasshouse, supporting local economic activity. Similarly, local dairy and cropping farmers are using digestate generated through the process as a substitute for mineral fertilisers, leading to further opportunities for nutrient recycling and soil conditioning.

Together, these linked material and energy flows demonstrate how coordinated infrastructure, logistics and partnerships can support emissions reduction and resource recovery objectives. The Reporoa model illustrates the potential benefits of aggregating organic waste streams across sectors and regions to achieve economies of scale and maximise the value recovered from organic waste.

The suitability and effectiveness of organic waste processing technologies depend on factors such as the type and quality of the waste, scale, local conditions and how residual materials are managed.⁴² This means that no single treatment pathway is appropriate in all situations. The Government’s October 2025 statement on biogas recognised this.⁴³ The statement signalled support for the development of a domestic biogas market as one option to convert waste to energy, potentially contributing to energy security and emissions reduction. 

Biogas can be produced using a range of technologies, including anaerobic digestion and landfill gas capture. Depending on the technology and local context, biogas may be used to generate heat and power on site or supply electricity to the grid, or it may be upgraded to biomethane for use as a renewable gas. Appropriately designed biogas projects can also contribute to energy security while helping to reduce emissions.⁴⁴ Where biogas is upgraded to biomethane, it can be injected into the existing gas network and provides a low-emissions alternative for industries where electrification can be challenging. 

The availability of government advice on biogas is currently limited. The Ministry for the Environment’s existing waste-to-energy guidance⁴⁵ has not been updated since 2020 and only briefly refers to anaerobic digestion and biogas. Updated guidance could provide clearer information on waste-to-energy processes for councils, businesses and communities – comparing these with other organic waste processing options and noting any relevant technical, regulatory and emissions considerations. This would support more informed decision making and reduce uncertainty for those considering investment in biogas and anaerobic digestion projects.

^{42 Eunomia. 2023. Waste to Energy Technology Implications in the Aotearoa New Zealand Context (PDF 2.9MB). Prepared for the Waikato Regional Council and Tauranga City Council by Eunomia. Hamilton: Waikato Regional Council.} 

^{43 Ministry of Business, Innovation & Employment. 2025. Government Statement on Biogas (PDF 796KB). Wellington: Ministry of Business, Innovation & Employment.} 

^{44 International Energy Agency. 2025. Outlook for Biogas and Biomethane: A Global Geospatial Assessment (PDF 9.5MB). Paris: International Energy Agency.} 

^{45 Ministry for the Environment. 2020. A waste to energy guide for New Zealand (PDF 771KB). INFO 964. Wellington: Ministry for the Environment.}