As New Zealand accelerates toward a low-emission future, public transport sits at the centre of that transition.
Kinetic NZ engaged DGE to electrify its Halsey Street Bus Depot in Auckland’s Wynyard Quarter, transforming an operational diesel depot into a future-ready electric charging facility.
Stage 1 of the project enabled the charging of 12 new electric buses, forming part of Auckland Transport’s broader commitment to achieving a fully emission-free bus fleet by 2035. With approximately 85% of AT’s operational emissions historically coming from diesel buses , this project represents meaningful progress toward decarbonising the city’s transport network.
This was not a new build. It was a complex live-site retrofit, requiring smart planning, careful staging, and future-focused infrastructure.
The Challenge
Retrofitting a Live Diesel Depot
Unlike a greenfield project, the Halsey Street Depot was fully operational throughout construction . Diesel buses continued running daily services while DGE installed the infrastructure required for electric fleet rollout.
Working within a live transport environment required:
- Careful staging of works
- Maintaining operational continuity
- Strict safety management in a high-traffic depot
- Coordinating commissioning with fleet rollout timelines
Underground Surprises
During trenching and civil works, the team uncovered previously undocumented historic tram tunnels beneath the site .
This discovery:
- Disrupted trenching routes
- Required additional excavation and concrete remediation
- Involved structural filling and reinforcement
- Resulted in lost time during a programme that was already tight
The team had to redesign sections of the underground routing, undertake additional concrete cutting and reinstatement, and recover lost time without impacting delivery.
Despite the setback, the project was delivered to programme.
Tight Programme & Fleet Deadlines
The electrification works were directly tied to the commissioning of new electric buses . Delays were not an option.
With the groundworks delay compounding an already compressed timeline, DGE had to accelerate delivery and coordinate closely with Kinetic’s project team to ensure charging infrastructure was ready for fleet activation.
Smart Power Management
Charging heavy electric buses introduces significant load demand. Simply allowing all buses to charge simultaneously at full capacity would overload the system.
Working closely with Kinetic, DGE assisted with commissioning a smart load management system into the charging infrastructure to ensure safe, efficient power distribution across the depot.
This ensured:
- Controlled energy distribution
- Staggered charging cycles
- Grid capacity optimisation
- Protection of existing infrastructure
This level of intelligent energy control required specialised understanding, this was far more than a standard electrical install.
Our Solution
DGE delivered a comprehensive electrical package designed specifically for heavy-vehicle electrification.
- EV Charging Infrastructure
- Installation of 12 EV bus charging units (Stage 1)
- Switchboard modifications and distribution upgrades
- Integrated load management systems
- Monitoring and smart energy management capability
- Civil & Underground Works
- Trenching and underground reticulation
- Resolution of historic tram tunnel obstruction
- Additional concrete cutting, reinstatement and structural remediation
- Installation of additional underground ducting for future expansion
Future-proofing was embedded into Stage 1, ensuring infrastructure pathways are ready for later stages, including gantry charging systems planned in Stage 3 .
- Scalable, Staged Delivery
The depot electrification is being rolled out in stages:
- Stage 1 – 12 buses
- Stage 2 – Additional charging capacity
- Stage 3 – Gantry system expansion (bringing the capacity up to 40 buses)
By designing with expansion in mind, DGE ensured that today’s installation supports tomorrow’s fleet growth, without costly rework.
Sustainability & Innovation
This project directly supports Auckland Transport’s commitment to an emission-free fleet by 2035 .
Key sustainability impacts include:
- Reduction in diesel fleet emissions
- Smart load balancing to optimise energy efficiency
- Infrastructure designed for long-term electrification
- Enabling scalable, renewable-ready charging systems
Electrifying heavy transport is one of the most significant levers available to reduce urban emissions. By delivering the electrical backbone for this transition, DGE is helping power the future of Auckland’s public transport network.
The Outcome
Despite unforeseen underground conditions, a live operational environment, and tight commissioning deadlines, DGE successfully delivered Stage 1 of the Halsey Street Electric Bus Depot on programme.
The depot can now:
- Support 12 electric buses immediately
- Scale for staged expansion
- Operate with intelligent load management
- Maintain operational continuity
Safe. Scalable. Future-ready.
