Tamaki Makaurau marked an exciting milestone on its path to decarbonisation with the opening of New Zealand’s first fully electric bus depot in Panmure, a joint project from Auckland Transport, NZ Bus, Kinetic and Vector.
The Panmure bus depot formerly housed 44 diesel buses (and diesel tanks), but now it’s home to 35 electric buses – each one able to be charged up to 502kwh each night, via fast DC chargers.
If all of them plugged in at peak time, it would require a significant investment in the network.
That’s where Vector’s Grid Impact Study came into play. Along with the team at AT, we assessed the requirements of a high-voltage connection to the depot and the charging infrastructure needed to supply it.
Together with NZ Bus we adopted a smart-charging system, which will be connected to our Distributed Energy Resource Management System (DERMS). This will manage e-bus charging dynamically to avoid increasing peak demand, while guaranteeing full charging overnight and during many times of the year when the network is unconstrained.
Vector’s chief operating officer of electricity, gas and fibre, Peter Ryan, explains: “One of our key focuses is on ensuring an affordable transition to a zero-carbon future and the smart charging system is a crucial part of that. By managing the timing of the e-bus charging, we can ensure the buses are ready for service each day, while keeping the cost of electrification down.”
The system also future proofs the depot for potential development of additional Bus to Grid (B2G) systems (which are being assessed overseas) to transfer surplus energy from bus batteries back to the network.
The 35 electric buses at the Panmure depot are part of the first tranche of the order of 152 e-buses agreed between AT and NZ Bus in November 2021. There will be 100 electric buses on Auckland streets by the end of 2023, including the first electric double decker! The next fully electrified bus depot will be in New Lynn.