Hybrid-electric buses out of action

The red buses have proven to be unreliable. Photo / Doug Sherring

Auckland's hybrid-power buses - once trumpeted as the future of inner-city public transport - have been taken off the road indefinitely because of reliability issues and replaced with diesel vehicles.

The City Circuit free service was introduced in 2003, using three red hybrid-electric buses arriving at 10-minute intervals on a route encompassing Britomart, Queen St, the Sky Tower and university campuses.

Each costs $560,000 - twice the price of a new diesel bus. Ratepayers meet the bulk of the cost, with the Auckland Regional Transport Authority paying $786,000 a year, Auckland City Council $40,000, and the Heart of the City business association chipping in.

Two of the three lie idle at the Westhaven depot of contractor NZBus. Heart of the City chief executive Alex Swney said the situation was "disappointing" and the association was reviewing the service.

"We have a reliability issue with some of these buses," he said. "We've discovered, along the way, it doesn't seem to be as durable as tried-and-true diesel."

Transport authority spokeswoman Sharon Hunter said two buses were off the road and fossil-fuelled vehicles were being used instead.

She responded to inquiries with this statement: "There are two buses out of action (these have turbine faults) and are waiting on parts from the USA.

"It does take time to obtain the parts. However, in the interim, Euro 3-compliant [emission standard] buses are being used on the City Circuit. Whenever a City Circuit bus is out of action, we expect NZBus to put an alternative vehicle on the road.

"ARTA recognises the reliability problem with the City Circuit service. It's been identified as an issue with the Capstone Micro Turbine, which generates electricity for the buses. The solution is to remove the 'hybrid' element from the buses concerned so they will be retro-fitted with brand-new Euro 5 engines, therefore they will not be branded as hybrids any more."

John Turton, who heads research and development for the bus-builders, DesignLine of Rolleston near Christchurch, said: "Obviously the turbine can be fixed and replaced. If that was done, these vehicles would be back up running again."

He said he would not be keen on diesel replacing the hybrid engines. "It would be disappointing if they did that."

NZBus says: "The contract does stipulate that the buses used to run the services are hybrid-electric vehicles [HEVs]. The HEVs will be back on the road as soon as possible."