Eco-cars and e-mobility Featured

Can luxury be accompanied by sustainability in high-performance cars for the cities of today and tomorrow?
by 25 August 2010

In 1925, Henry Ford said that ethyl alcohol was "the fuel of the future." In his opinion, "There's enough alcohol in one year's yield of an acre of potatoes to drive the machinery necessary to cultivate the fields for a hundred years." Rudolf Diesel ran the engine named after him on peanut oil for the 1900 World's Fair. It will surely come as no surprise, then, to discover that pedigree auto manufacturers, for whom in the past the engine's oil-burning capacity is much less a consideration than performance, are actually turning green.

In some cases, green in literal terms. Ferrari recently showcased the experimental Hy-Kers Hybrid vehicle, which has a bright emerald livery in total contrast to the marque's usual red. The Hy-Kers hybrid is a development of the 599 GTB Fiorano, in which fuel consumption is reduced by KERS (kinetic energy recovery systems) technology based on Formula 1 systems. A compact, high-voltage electric motor is coupled to the 7-speed transmission, so that it can seamlessly supplement the power produced by the V-12 engine. When the driver touches the brakes, the electric drive unit becomes a generator, using the kinetic energy to recharge a series of flat lithium-ion batteries. All this extra equipment weighs quite a lot, but it is positioned below the centre of gravity, and does not affect the amount of room in the interior and the luggage compartment. The result is over 100 HP extra power from the electric drive unit, and a 35% reduction of CO2 emissions in typical urban cycle conditions.

Similar things have been going on in Norfolk, UK, home to sports car manufacturer Lotus. As Dany Bahar, CEO of Group Lotus, says, "The Lotus Elise revolutionised the sports car when it was launched 14 years ago, and now the Lotus Elise has become greener, giving drivers access to class-leading performance with less guilt." The Lotus approach has always been one of generating superb performance and handling through lightweight construction, as exemplified by the Lotus Evora, the first all-new Lotus since the iconic Elise. However, the new "eco-Elise" takes this concept even further, and the chassis in aluminium with a lightweight steel subframe weights just 68 kg. The car itself weighs in at just 876 kg, making it one of the lightest sports cars. This contributes to giving it probably the lowest CO2 emissions for any petrol high-performance sports car in the world. The 2011 model year Elise has been given an extensive redesign, with new bodywork features, new headlights including LED day-time running lights and LED direction indicators, and improved aerodynamics that reduce the drag coefficient by 4% for better fuel economy. Most importantly, the power plant for the 2011 Elise is an advanced 1.6 litre Valvematic (variable valve-lift mechanism) engine, therefore 200 cc smaller than the previous Elise, while producing similar power, and improving fuel economy by 20% and reducing CO2 emissions by over 16%.

Engine output is optimized by the bespoke Lotus T6 engine management system, and cruise control. But, apart from all these details, in sports cars the old aviation adage "if it looks right, it flies right" holds true, and in the new Lotus Elise, the spectacularly good looks are accompanied by the classic Lotus tarmac-hugging performance. The driver becomes part of the car, rather than being just a passenger. Paul Newsome, director of Lotus Product Engineering, says, "We are always looking at ways of keeping the Elise ahead of its peers, and for the 2011 model year, we have improved efficiency without losing the innate fun that has made the Elise legendary."
While Ferrari and Lotus are working on optimizing the use of petrol, BMW are moving in another direction, that of abandoning the use of fossil fuel altogether. In today's society, there is increasing concern about climate change, global warming, and the scarcity of resources. Not long in the future, the point of peak oil extraction will be reached, and from then on, the gulf between supply and demand will grow ever wider. In addition, on a worldwide basis, society is becoming increasingly urbanized. Today, more than half the world's population live in towns and cities, and this is forecast to reach 70% by 2050. In the world's 30-odd megacities (such as Shanghai, London, Los Angeles and Tokyo), zero-emission vehicles will become essential to maintain tolerable living conditions.

BMW's response is E-mobility. "Electromobility allows people to be individually mobile without polluting the environment with harmful emissions," says Martin Arlt (Electric Mobility, BMW). An example is the Megacity Vehicle, due to be launched on the market in 2013. Klaus Draeger, BMW Development Manager, says, "The Megacity Vehicle is a revolutionary automobile. It will be the world's first volume-produced vehicle with a passenger cell made from carbon. The drive system remains the heartbeat of a car, and that also applies to electric vehicles." He thus summarizes the fundamental problem of electric vehicles: the fact that such a car is typically about 300 kg heavier than a petrol-engine car. Hence the use of lightweight carbon-fibre reinforced plastic, and the LifeDrive concept. The Drive module comprises the battery, drive system and structural functions, while the Life module consists of a high-strength, lightweight passenger cell.

But what about performance, and range? In actual fact, electromobility offers an exciting driving experience, because the entire torque of an electric motor is available from a standing start, accelerating right up to top speed without interruption. This means a high fun factor. In addition, when you drive an electric engine, and take your foot off the throttle, the car actively decelerates, and the deceleration torque is recovered by the electric motor which becomes a generator, converting kinetic energy into current and feeding it back into the vehicle's battery. The system recycles up to 20% of the energy consumed, and of course it is ideal for use in the city, where traffic lights, pedestrians, traffic wardens and shopping stops require frequent changes in speed.

Range is more of a problem, because a typical battery in an electric vehicle contains the same amount of energy as in just three litres of petrol. The BMW ActivE concept vehicle with lithium-ion batteries provides a range of about 160 kilometres. Research is continuing, but it is probable that hybrid solutions will continue to be the only practical systems for at least a few years. And in the long term, vehicles may be based on a combination of battery power and renewably generated hydrogen. Which will be greener even than Henry Ford's concept of cars running on potatoes.

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