An electric vehicle uses electric motors and motor controllers instead of an internal combustion engine, with energy stored on board in suitable electrochemical systems—typically battery packs. Capacitors or other storage technology has also been used successfully. The batteries may be charged from a standard electricity outlet or, in the future, may be swapped at specialised exchange stations. Some of the energy normally lost as heat during braking can also be recovered by using the motor as a generator during braking.
Fully electric drivetrains are considered most suitable for urban applications where regenerative braking can be maximised in stop-start driving, and where a limited range is not as significant.
The power and torque requirements of heavy duty vehicles suggests that the technology is most appropriate for light commercial vehicles in an urban application, although some trials have shown electric freight vehicles up to 10 tonnes can be successful.
Despite a high capital cost, fully electric vehicles can produce major fuel cost savings compared with conventional fuels (Jamison Group 2008). Adelaide City Council found a 50% decrease in fuel costs associated with the Tindo electric bus compared with a diesel bus (Adelaide City Council 2008). The financial performance over the entire vehicle life will depend on the service life of the technology, the mileage covered and the changes in maintenance costs.
Environmental benefits at the tailpipe are also considerable, with fully electric vehicles being zero emissions at this point. But emissions from the full fuel cycle are not zero and depend largely on the fuel used to supply the national grid (predominantly coal in Australia).
Key implementation considerations
Consideration should be given to the capital cost of electric drivetrain technology. This means that an acceptable payback period is contingent on the operational life and annual kilometres travelled by the vehicle.
The potential for escalating electricity costs (in excess of the expected rise in conventional fuel costs) should also be taken into consideration in any investment decision.
Examples of implementation
Tindo Bus, Adelaide
This brochure highlights the potential for fully electric drivetrains to be used in a heavy vehicle application, with charging provided by renewables.
Adelaide City Council introduced the world’s first solar-powered electric bus that is recharged using 100% solar energy. The bus does not have a combustion engine, making it a very quiet, zero emissions vehicle.
The bus has covered over 55,000 km, saving the Council over 14,000 L of diesel and over 70,000 kg of CO2-e in its first year. The bus can travel about 200 km between recharges under typical urban conditions. The capital cost of the bus and solar installation was funded by the Adelaide City Council and the Australian Government through the Adelaide Solar City Program.
For more information, see Adelaide City Council (2007) Tindo solar bus: the world’s first solar electric bus (opens in a new window) PDF 1.9 MB.
This case study demonstrates the potential for fully electric drivetrains to be successfully implemented in a heavy duty freight application.
TK Maxx added a 10 t fully electric Smith Newton vehicle to its distribution fleet. The truck provides the largest carrying capacity for an electric truck, with a body length of 7.5 m and a cargo payload of over 4000 kg.
The vehicle has a top speed of 80 km/h, and after it has been fully charged over a 6–8 hour period, it has a range of up to 200 km.
For more information, see Smith Electric Vehicles (2011) TK Maxx case study.
This case study illustrates the potential for fully electric trucks to present significant fuel cost savings in a logistics application. TNT began running a fully electric 7.5 t truck in 2006. Following its success, 50 more trucks were ordered in 2007 and a further 50 in 2008. The Newton’s body panels are built from an ultra-light material that increases the payload capacity to 4000 kg. Fuel costs were reduced by almost 80% when considering the cost of electricity versus that of diesel
For more information see Smith Electric Vehicles (2011) TNT Express case studies.
For the full report, see Fuel for Thought – Identifying potential energy efficiency opportunities in the Australian road and rail sectors (opens in a new window) PDF 1.5 MB.