One company at the leading edge of the EV charging sector is global force Siemens. ABC recently caught up with Siemens Australia’s Olivia Laskowski, who travelled to Europe to review best practices and potential applications for EV charging infrastructure in Australia
In Australia’s great bid to electrify its heavy vehicle fleet, there’s one obstacle currently standing in the way – charging infrastructure. While vehicle technology continues to grow by the month, a combination of factors is preventing charging plans from matching zero-emission goals.
As a prominent Australian technological force, Siemens is constantly revolutionising electric bus charging infrastructure. To combat the charging challenge and identify best practices from EV installations, Siemens Australia’s electric charging infrastructure lead Olivia Laskowski visited international bus depots featuring innovative Siemens designs and technology.
“The EU is one of the most progressive economies globally when it comes to charging infrastructure and I was lucky to recently visit several depots across the region,” Laskowski told ABC.
“One of the main reasons for my travel was to see different design options for overhead charging infrastructure solutions for plug-in cables.”
Laskowski’s trip involved visiting three European depots using different Siemens charging technology. Her journey took her across Switzerland and two depots in Germany using the Siemens Sicharge UC high-power charging infrastructure range with overhead dispensers.
Despite all featuring Siemens chargers, the sites involved a different cable management system for its CCS2 charging cables. Each depot had one key feature in common – they all involved retrofitting equipment into existing infrastructure.
Laskowski’s journey began along southeast Germany’s Danube River in the well-preserved Bavarian city of Regensburg.
“The city of Regensburg introduced electric buses to its operations back in 2021, when Siemens was engaged directly by the operator for complete electric and civil designs and also helped build the transformers and charging infrastructure,” Laskowski says.
“It was interesting to see that the depot uses two 1.25MVA transformers installed inside so one can be switched off for maintenance. All chargers continue to charge from a single transformer.”
Laskowski says the chargers were installed in banks of five, with four connected to single overhead dispensers while the last used an integrated cable. The operator opted for overhead charging solutions at the site due to the lack of space to expand existing depot sheds or parking bays.
“Germany also deals with a unique civil works hazard in that when you dig into the ground, you might unexpectedly unearth a WWII bomb, reducing the appetite to dig cable trenches,” Laskowski says.
“The customer had experience with spring-loaded air hoses across the site that retract the air hose above the buses and was keen for a similar solution for the CCS2 charging cables.”
Siemens achieved this by using cable reels operated by a simple pull switch hanging between parked buses. This first visit taught Laskowski that some drivers activate the cable reel with the pull string without removing the plug from the bus, damaging it or the bus’s socket.
She left knowing that a simple fix was to provide a second string that activates the retraction of the cable back up with resistance, allowing drivers to recognise if the plug is still connected to the bus.
Laskowski found that the customer requested installation of the dispensers and cable reels on an overhead gantry, fully independent of existing depot sheds, to allow for future renovation or demolition plans.
“Siemens responded by supplying a steel gantry spanning five bus parking bays to mount everything to,” she says.
“This means the gantry may sit inside the depot shed, but it remains independent of the existing building.”
Laskowski’s second stop brought her to Switzerland, in the sixth district of Winterthur in the quarter of Hardau.
The depot here began commissioning Sicharge UC equipment in January last year, with 75 charging centres planned to be installed at the site along the walls or between structural columns and ultimately connected to overhead dispensers.
Inside the fully enclosed depot, Siemens provided transformers for the private medium voltage network, which were then connected to a retractable cable system that was both practical and economical to install and maintain.
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“A joint design effort between the customer and Siemens resulted in a spring-loaded balancer,” Laskowski says.
“The coiled cable is lowered by pulling on a string hanging between the buses. Ten-metre cables are used at this site to enable the length and flexibility to reach the charging sockets for several bus brands and models in the fleet, both articulated and non-articulated, with sockets located either at the front, side or back.”
In a genius move, the same pull string is then used to retract the cable back up to its coiled positive above the buses through a simple tug of the string. While the first string design turned out to be too thin, leaving it at risk of getting caught in the bus side mirror, Siemens provided a thicker string to ensure it didn’t get stuck or damage the mirror or spring-loaded balancer.
Laskowski says her visit to Switzerland showed what can be done with retractable cables. Her final stop took her up north to the major port city of Hamburg, Germany.
“The Hamburg electric bus depot is one of the largest electric bus depots in Europe with more than 96 high power DC chargers installed from different manufacturers,” Laskowski says.
“Siemens began commissioning Sicharge UC charging infrastructure at the site in August 2021. Hamburg’s depot consists of large undercover bus parking bays, and the charging infrastructure is housed in rooms sitting on top of the bus shelters.”
Before electric buses were introduced to the city, the depot had existing cables hanging from the bus shelters’ roofs to provide auxiliary power supply for cleaners and air hoses.
The cables, which hang between the parked buses, were quickly used by Siemens to connect to overhead dispensers similarly. Laskowski observed on her trip that using existing features is a key part of getting the most out of depot charging infrastructure.
“Some cables were configured as permanently hanging without the ability to retract, while others were longer and hung off cantilevers beyond the canopy of the depot roof,” Laskowski says.
“Another cable configuration used at the site is a sliding overhead rail, enabling the CCS2 plug to match the location of charging sockets of longer articulated buses.”
While hanging cables is a simple and effective infrastructure strategy, Laskowski discovered the challenges with this installation method. Strong winds hitting the depot can cause the cables to swing, increasing the chance they’ll hit a bus headlight or get caught by a side mirror, causing unnecessary damage to the bus, cable or dispenser.
The successful trip has given Laskowski more ideas on how to help accelerate the electrification of Australia’s bus and coach fleet.
“This journey has been incredibly enriching. To see our charging solutions in unique operations across Europe has broadened my perspective significantly,” Laskowski says.
“I look forward to applying these valuable insights to enhance the efficiency of Australian bus depots, contributing to our country’s sustainable future.”