Refined all-electric Joule debuts at the International Motor Show in Geneva: Joule, the revolutionary electric vehicle from South African company Optimal Energy, is on display at the 80th International Motor Show in Geneva in a form tantalisingly close to the planned production version.
Designed by South African-born Keith Helfet, Joule has been developed from a static display model and engineering prototype into a pre-production prototype by Zagato’s Total Design Centre, and Joule deservedly forms the centrepiece of a stand at Geneva shared by Optimal Energy and the iconic Milanese design house.
The Optimal Energy-Zagato-Helfet team has made a number of changes to Joule and the car shown in Geneva is somewhat different, especially at the rear, from the version first unveiled in Paris two years ago. This car was hand-built on the outskirts of Port Elizabeth, South Africa by Hi-Tech Automotive, which is responsible for building a marketing and test fleet of approximately 100 vehicles. These will double as research and development units, some of which will be on South African roads by the start of the Soccer World Cup in June.
The Interior of the All Electric Joule
Joule’s mantra is Born Electric. A key strength and differentiator of Optimal Energy is freedom from many of the constraints that affect traditional car companies. As virtually the only automotive manufacturer focused exclusively on electric cars for the mass market, everything Optimal Energy does is directed towards achieving that goal. Not only has this fresh approach led to the creation of a new kind of car, but it will ultimately also lead to a new way of buying a car and a new kind of customer ownership experience.
Full-scale production of Joule will begin at the end of 2012, with cars in showrooms by mid-2013. Key design goals for the finished product include a range of 230 kilometres based on the New European Driving Cycle (NEDC) or 300km using the Urban Dynamometer Driving Schedule (UDDS), integration with existing charging infrastructure, a genuine freeway cruising capability, seating for five, a 4-star NCAP safety rating and a retail price of €24 300 in today’s terms.
Optimal Energy has signed a Memorandum of Understanding with EDAG, a German automotive full service supplier, to industrialise the Joule. EDAG has built an outstanding reputation working with many well known carmakers over the past 40 years, and in partnering with EDAG, Optimal Energy is ensuring that the best of German automotive engineering will be integrated into the series production Joule.
Optimal Energy has also signed a Memorandum of Understanding with Energy Innovation Group (EIG), a South Korean lithium battery cell supplier, to explore the potential of setting up a manufacturing facility in South Africa, for the non-exclusive supply of cells to Optimal Energy. The Industrial Development Corporation of South Africa (IDC), as potential investor, is party to this Memorandum. The IDC is currently an investor in Optimal Energy.
The Department of Trade and Industry (DTI) of South Africa has just announced its 2010 – 2013 Industrial Policy Action Plan, in which the commercialisation of South Africa’s electric car is specifically addressed. This includes the provision of appropriate support to encourage local manufacture of EV’s and related components, infrastructure roll-out for such EV’s, creation of testing facilities, provision of demand stimulation mechanisms and public education on the use and benefits of alternative energy source vehicles. These are major steps towards reaching Optimal Energy’s vision of establishing and leading the electric vehicle industry in South Africa and expanding globally.
Once production of Joule begins, CEO of Joule manufacturer, Optimal Energy, Kobus Meiring estimates that Optimal Energy, which currently employs more than 100 highly-skilled permanent personnel, will increase headcount to around 2 300 employees, while a further 8 000 people will be employed in various related and support industries. “We are in the process of selecting a site for our first assembly and manufacturing plant. The location of the plant will be announced later this year,” continues Meiring.
From the start Joule was conceived as a fully electric vehicle (EV), with all aspects of its design – from the styling to the safety features – reflecting this. Legendary ex-Jaguar stylist Keith Helfet came up with a shape that is a breakthrough in design and practicality yet has a drag coefficient that puts it at the forefront of aerodynamic efficiency. Joule will also boast a list of features that will make it exceptionally user-friendly, including clever packaging, an infotainment system, connectivity and navigation. All of these design features will make Joule the most practical and intelligent car that an urban motorist can own.
The Joule is powered by a 36 kWh traction battery. The function of the battery is to provide the energy required to power the electric motor of the Joule. In order to fulfil this function, the battery controller manages the energy transfer during charge, discharge and regeneration, a process that involves complex monitoring processes as well as sophisticated communication with other vehicle systems.
The traction battery consists of a number of modules, each module containing lithiumion cells. These cells are at the forefront of battery technology and safety, and have a high specific energy density. This allows the Joule to achieve the desired range without the mass penalty of older technology batteries.
The battery pack is mounted onto battery trays which slot into the vehicle from below and which can be replaced within few minutes. These trays form an integral part of the structure, and their location serves to ensure a low centre of gravity which reflects in the Joule’s handling characteristics. The Joule range is 300 km according to the Urban Dynamometer Driving Schedule (UDDS) and 230 km using the New European Driving Cycle (NEDC).
The all-wheel disc braking system provides excellent braking performance, including safety features such as ABS. Joule is also equipped with a regenerative braking system which, during deceleration, converts kinetic energy into electrical energy. This is used to recharge the traction battery, thus extending the range of the vehicle. The regenerative braking system operates separately from the standard brakes and is actuated when the accelerator pedal is released. This allows virtual “single pedal driving”, providing very easy and comfortable control of the car.
With its simple, elegant lines and self-assured stance, Joule displays a timeless appeal, which sets it apart from the competition. Styling does not compromise the aerodynamics of the vehicle, and Joule’s design is inherently aerodynamically efficient. This allows for maximisation of the vehicle range, especially important at high speeds. An on-going drag reduction program is in place to improve efficiency. The thermal and reflective properties of the paint and windows are being optimised in order to reduce the energy required to cool and heat the vehicle.
The design of the chassis ensures that the vehicle mass is kept to a minimum without compromising crash safety or handling characteristics. This has been achieved by making the battery tray an integral part of the chassis, maintaining stiffness and strength without adding mass. The judicious use of high strength steels, provided by one of the world’s greenest steel producers, also ensures that mass is reduced without sacrificing strength.
Propulsion is by means of a transversely-mounted synchronous permanent magnet motor providing 75 kW peak power and a peak torque of 280 Nm. The motor drives the front wheels through a 7.4:1 single speed reduction gearbox/differential unit.
Performance is brisk with a 0-60 km/h acceleration time of less than five seconds, 100 km/h coming up in under 15 seconds. Maximum speed is 135 km/h, making Joule perfectly suitable for highway driving.
A uniquely integrated computer developed from EV-specific architecture controls all Joule’s on-board systems and ensures – amongst other things – that the instant torque available on pull-away is properly managed to prevent wheel spin. An integrated, programmable on-board charger ensures that no external charging infrastructure is required and that charging can be synchronised with off-peak electricity.
The Joule is essentially a city car, and its suspension and steering system reflect this. It is equipped with an electric power steering and has a turning circle of under 10 metres for exceptional manoeuvrability.
The front McPherson struts, combined with independent rear suspension, delivers a modern design with superior dynamics and handling. Wheels and tyres form an integral part of a vehicle’s suspension and low rolling resistance tyres contribute to Joule’s efficiency. Custom 16-inch light alloy rims are standard, reducing unsprung mass and contributing significantly to the Joule’s handling characteristics.
The Joule is designed as a five-seater. The two front seats are equipped with adjustment for height, fore/aft and recline. They are separated by a central console which provides armrests and storage space.
The rear seat is moulded with three individual seat positions. The folding backrest allows luggage volume to be progressively increased when necessary, for maximum versatility. Joule has a luggage volume capacity of up to 700 litres, with seating flexibility similar to an MPV.
A photo-voltaic solar panel mounted on Joule’s roof will be offered as an option. The energy generated by this panel may be used in various ways, internal environmental control being the most efficient. Electricity generated in this manner could also be fed back into the traction battery or used to power ancillaries such as daytime running lamps or entertainment systems.
The charging system has been designed to be intuitive, automatic and safe, allowing Joule to be simply plugged in and left to charge. Normal charging is from a single phase 230v / 16A supply to a charge point located on the Joule.
The ability to integrate with existing charging infrastructures is of paramount importance, research is being done on how best to design a system that can integrate with current (and future) systems. Integration with modern “Smart Grid” electrical networks is being investigated, so as to optimise energy usage and provide Joule users with the most cost-effective charging options.
Because an EV has minimal mechanical noise, and in Joule’s case, almost no wind noise either, the suppression of interior and road noise is of vital importance. This is addressed in various ways, including careful tyre selection and suspension tuning.Pedestrian safety is vital and Optimal Energy is investigating ways of warning pedestrians of Joule’s approach without generating intrusive noise.
Joule is designed for ease of maintenance. With substantially fewer moving parts, there is considerably less wear and tear, and the regenerative braking system also reduces wear on the braking system. Likely service intervals will be 40 000 km or two years, the absence of oil as a lubricant further adding to Joule’s environmental credentials while saving money.
With Joule’s vehicle control system continuously monitoring the state of health of the vehicle, service information will be regularly downloaded and analysed, allowing a vehicle to be called or scheduled for repair or maintenance before failure occurs. The design is also being optimised to reduce repair times and costs, as these have a significant effect on insurance costs. Attention is being given especially to the repair of damage sustained during city (low speed) use, as this is the environment where Joule will mostly operate. Not only is the pressed steel body designed to be easily recyclable and repairable, but special attention has been given to the extremities and corners to ensure they are as damage-resistant as possible.
Safety was paramount in the design of the Joule, and the design goal is a minimum Euro NCAP 4-star rating when it goes on sale. Airbags, ISOFIX child seat attachment points, stability control and anti-lock brakes, features ensuring the safety of the high voltage electrical systems: all are an integral part of the design.
