Brisbane Metro – Charging Ahead with an Australian-first Electric Bus Fleet
Video: Brisbane Metro - charging ahead with an Australian first from Hitachi Energy
Transportation decarbonisation: a key priority
Transportation is Australia’s third-biggest contributor to greenhouse gases.[1] Therefore, transitioning the transportation sector to zero emissions is critical in the fight against climate change.
Hitachi Energy was given the chance to work on an Australian first, high-performance fleet of electric buses to transform Brisbane’s bus network, unlocking capacity and helping get more people to where they want to go, at the times they want to travel.
The 60 new electric buses are manufactured by HESS and powered using Hitachi’s high-tech Grid-eMotion® infrastructure.
Charging up
When planning the electrification of Brisbane Metro, choosing the right technology to support the battery and charging needs of a reliable metro bus service was crucial for Hitachi Energy.
First, they needed to implement the robust electrical infrastructure that is required to charge large fleets of buses. Therefore, they equipped Brisbane Metro with two types of chargers for its fleet of 60 buses: flash stations at the end of a route using overhead feeding stations, and Combined Charging system (CCS2) plug-in chargers which are used at depots to condition batteries and increase the battery lifespan. The flash charging system relies on the power electronics mounted onboard the bus, which are used to power the motor and wheels.
The next challenge was battery choice – a technology which is rapidly evolving and needs to suit the particular operating environment. They decided to fit the metro fleet with lithium-titanium-oxide (LTO) batteries, which have a unique chemistry perfectly suited to multiple charges throughout the day, instead of a single charge to last the entire day.
There’s also a Power Load Management system to optimise and moderate electrical current drawn from the grid.
Through this carefully-planned technology, Hitachi’s Grid-eMotion® equipment strikes a balance between battery size and life, infrastructure requirements and operational efficiency.
Maintaining frequency and reliability
For Brisbane Metro, it was essential to build infrastructure that enables frequent and reliable service. Hitachi carefully selected the batteries and charging power to ensure each bus can travel along a route with sufficient battery charge, even during peak times.
Hitachi Energy’s roof-mounted Energy Transfer system connects when the metro’s door brake is activated, automatically starting to charge within seconds of the bus arriving at a charge point, and recharging in six-and-a-half minutes. This automatic system also means bus drivers don’t have to think about connecting to chargers, plus there’s no need to carry large batteries on board, freeing up room for additional passengers.
Even the power system is designed for reliability; it connects directly to the medium-voltage electricity grid, allowing the buses to continue their journey quickly, and minimise damage to batteries over time.
At the depot, there is room for 60 buses, with a compact independent 50 kW charger for each vehicle overnight and during extended parking periods. The buses are connected at low power using a CCS2 plug to ensure the batteries stay conditioned and each bus is heated or cooled for passenger comfort before departure.
Hitachi’s dedication to a more sustainable future
This is a pivotal time to prioritise a net-zero society in Australia. Hitachi is proud of its role in helping to decarbonise transportation in a major Australian city and creating a more sustainable future through electrification. The Grid-eMotion® infrastructure not only ensures the performance, frequency and capacity of bus services in Brisbane, but provides a sustainable and energy efficient solution that integrates seamlessly into the network.
[1] Australian Government: Quarterly Update of Australia’s National Greenhouse Gas Inventory: September 2019
