Puwera Landfill Gas Generation Project
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Northland Waste
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Pacific Energy
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Puwera Landfill, Northland, New Zealand
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1.56MW Landfill Gas Generator
Overview
In partnership with Northland Waste, Pacific Energy successfully delivered a highly specialised 1.56MW landfill gas-to-energy project at the Puwera Landfill near Whangārei. The project not only contributes to Northland's sustainability goals but also demonstrates Pacific Energy's integrated delivery capabilities in complex energy infrastructure.
The Puwera installation converts landfill gas into renewable electricity, offsetting emissions and supporting the region’s transition to lower-carbon energy. However, the local network (Northpower) lacked the capacity to accept generation at the site. Pacific Energy devised an innovative alternative: exporting power to the private Golden Bay Cement (GBC) network, requiring the design and construction of a new 1.6km 11kV overhead line.
Client Background
Northland Waste is a fully New Zealand-owned waste management company operating across Northland, Auckland, and the Lower North Island. Through its 50% stake in the Puwera Landfill (jointly held with Whangārei District Council), it has invested in sustainable waste solutions, including biofuel production, composting, and gas capture.
Golden Bay Cement operates New Zealand’s only fully integrated cement manufacturing plant. The Portland-based facility produces approximately 850,000 tonnes of cement annually and is an industry leader in carbon reduction, substituting coal with biofuels like end-of-life tyres and construction wood waste.
Project Scope and Challenges
Pacific Energy led the project from concept to commissioning. The project faced a critical challenge: Northpower's local network could not support the additional generation. Pacific Energy identified and secured an export solution via Golden Bay Cement’s private 11kV network. This required extensive planning, regulatory navigation, and multi-party coordination.
Key deliverables included:
Grid Application & Compliance: Led the technical application to Northpower and coordinated export arrangements with GBC.
Electrical System Design: In partnership with Middleton Group, developed full electrical design, including protection studies, single line diagrams, switchyard layout, 400V cabling, and earthing systems.
11kV Infrastructure: Oversaw the design and construction of a 1.6km 11kV overhead line. Specified and procured all 11kV equipment including transformers, switchgear kiosks, pole-top breakers, air break switches, and metering units.
Project & Contractor Coordination: Acted as the central coordination point between multiple stakeholders including GBC’s electrical consultant, HV and overhead line designers, and all installation contractors.
Installation Oversight: Provided review of Eneraque’s generator and scrubber electrical drawings, ensuring integration with site power systems.
Testing & Commissioning: Oversaw the full commissioning process, including 11kV testing and validation. Reviewed all test data and ensured compliance with standards.
Programme Management: Developed and maintained a detailed project programme in MS Project. Chaired weekly meetings and tracked milestone delivery.
Technology Integration
The project involved the installation of a high-efficiency landfill gas generator supplied and installed by Eneraque. Gas from the landfill is first processed via a scrubber plant to remove contaminants, before being fed into the 1.56MW generator.
Pacific Energy ensured that all electrical and protection systems around this core plant were robust, integrated, and future-ready. Our team worked hands-on throughout the delivery phase, embodying a practical, solutions-focused approach to project execution.
Outcome and Impact
The Puwera project is now delivering renewable baseload electricity from waste gas, a first-of-its-kind connection to an industrial private network in the region. It offsets fossil fuel use at Golden Bay Cement and enhances Northland Waste's carbon reduction credentials.
Perry Hutchinson, Director at Pacific Energy Ltd, says that the Puwera project represents “a strong step toward sustainable energy solutions and showcases what’s possible when great minds come together.”
The team that Pacific Energy assembled also included Mahurangi Electrical, Ventia, Tyree NZ Ltd, HV Power, Arthur D Riley & Co Ltd, Powerpro, MSGNZ, IAMSL, and Eneraque Renewables.
This project showcases Pacific Energy’s end-to-end capability in:
Developing alternative grid export solutions
Designing and delivering medium-voltage infrastructure
Coordinating complex, multi-stakeholder energy projects
Providing hands-on technical and project management expertise
About Pacific Energy
Pacific Energy is a New Zealand-based engineering and project delivery company specialising in renewable energy and embedded generation projects. Our focus is on solving the technical and logistical challenges that others shy away from. From concept through commissioning, we bring the expertise, agility, and drive to deliver smart energy solutions for a low-carbon future.
