The Tindo buses in Adelaide were the first solar powered all-electric buses in the world and the first prototype was commissioned by the Adelaide council in 2008. The Tindo buses first commenced operation on 11/2/2008 and had operated for 60,000 km by 2010. (Tindo is the Kaurna Aboriginal name for sun)
The first prototype bus was so successful that a further 2 all electric buses were commissioned in 2010. Both the buses and the FIAMM SoNick batteries have exceeded all expectations of performance.
Overall, when compared to other electric buses now in operation the Tindo bus has one of the most demanding schedules in the world.
One of the reasons the SoNick battery technology was chosen was due to its safety. The SoNick battery is non-combustible so there are no safety issues with possible explosion or fire on impact in the case of a bus crash as there can be with lithium ion batteries. Another consideration was that the batteries are fully recyclable and the cost of recycling is included in the battery price. The SoNick batteries are virtually maintenance free, very lightweight and operate efficiently, no matter what the ambient temperature is and have a longer expected life cycle than other battery technologies.
The successful tender to build the Tindo bus was given to Designlife from New Zealand. Designlife expanded to the US and Abu Dhabi but are now no longer operational as a company, however, the SoNick batteries have been incorporated in vehicles by other manufacturers in widely varying temperature locations from Canada where they operate at -300C to Abu Dhabi where they operate in temperatures of +500C. Google shuttle are currently using the SoNick technology in their vehicles.
The Tindo buses, which are a 40 seater bus, use 11 sodium nickel chloride (SoNick) or Zebra batteries and are designed to travel for 160 – 200 km on a trip The Tindo bus also utilises a regenerative braking system that creates extra power to recharge the SoNick batteries. 2 extra SoNick batteries are kept in stock in case of any issues.
The buses are recharged using a 50 kW solar PV array on the roof of the bus depot which more than completely offsets the Tindo bus energy consumption via the electricity grid. If needed, the Tindo bus can stop to use a fast charger to increase its travel distance.
A display panel tells the driver how much further the bus can travel before the batteries need recharging. Many issues can affect the travel distance on any trip including driver behaviour, the number of passengers, weather and the traffic conditions which will affect the number of times the bus stops and starts.
In 2010, the SoNick batteries were replaced, not because of any issues with the batteries but because there were issues with the chargers that were needed to balance the charge of the batteries to keep them discharging at the same rate. There were no cell failures or noticeable degradation of the batteries, however, battery imbalances can negatively affect battery life through excessive discharging and cycling of certain modules in the pack. FIAMM replaced the batteries free of charge as continuing to use them would have severely affected the batteries lifetime.
One of the unanticipated problems with the running of the Tindo buses was their popularity. Many people made an effort to ride in the buses and as a result they often ended up carrying more loads than had been anticipated which put extra strain on the batteries. However, again the SoNick batteries performed better than had been expected.
The Tindo electric buses have now completed over 200,000 km around Adelaide streets.
In 2014 The Adelaide Council leased the buses to Torrens Transit who now operates the Tindo buses as a free Adelaide connector bus.
The buses were taken off the road in 2015 as government regulations changed and it was needed to provide more space for wheelchair access. Due to a variety of reasons the buses remained off the road for 1 ½ years during which time the SoNick batteries were sitting on the concrete floor in an uncharged state. When the batteries were ready to be recommissioned the engineers involved were worried that the batteries would no longer be useable but in fact, once they were again heated up to full charge state they were at the exact state they had been when they had been decommissioned with no degradation. This is a true testament to the longevity of the SoNick technology.
A Tindo solar – electric bus is estimated to reduce greenhouse emissions by 50 tonnes annually compared to a diesel bus of similar seating capacity.
Taking into account vehicle upfront purchase cost, maintenance and operating costs and allowing for a complete replacement of batteries over a 10 year period the following comparison was created for different bus technologies.
All Electric bus (40 seats) – $0.8131 / km
Hybrid Electric bus (40 seats) – $1.0792 / km
Diesel bus (24 seats) – $1.42 / km
If you would like to know more about getting the safe, reliable, recyclable, SoNick (molten salt) battery storage for your own transport, home, business or micro-grid application visit us at http://quantum.GridEdge.com.au