Steering ahead with alternative fuels
The world’s car- makers know where the future lies — and all have their answers to traditional petrol- driven vehicles, writes Philip Lord
THE world still awaits the arrival of a mass- produced, affordable, alternative- fuel zero- emissions car, but at least the fog has lifted on the most viable ways to reduce the car’s carbon footprint.
In the short to medium term the solution to the car’s fossil fuel use and CO emissions as
2 it stands today rests with clean diesels, hybrids ( petrol- electric or diesel- electric), hydrogen combustion and biofuels such as ethanol. In the long term, electric vehicles — running on mains power, hydrogen fuel cells or a combination of both — continue to offer the most likely solutions.
The most significant breakthrough so far this year was not a new clean technology as such but rather the US car manufacturers’ acknowledgement that heavy investment in such technology is now necessary.
The North American International Motor Show held in Detroit in January saw an unprecedented number of clean energy concepts. While the US car- makers continue to sell large, thirsty SUVs, at least they are working on low- emissions alternatives.
One such vehicle is the Cadillac Provoq, an SUV concept with a development of the E- Flex propulsion platform that debuted in the Chevrolet Volt Concept last year. The Provoq’s propulsion system uses electric motors powered by lithium- ion batteries, which are charged by a hydrogen- fed fuel cell stack.
It has a 70kW electric motor to drive the front wheels and two 40kW hub- mounted electric motors to power the rear wheels. The Provoq’s 0- 100km/ h acceleration time is 8.5sec and top speed is 160km/ h.
The twin 6kg hydrogen tanks that feed the fuel cell give a 483km range, while GM says Provoq will travel 32km on its lithium- ion battery power reserves alone.
The Provoq incorporates other energysaving technologies such as solar panels to feed power to interior lights and the audio system, which themselves are low- energy consumption items.
Another US car- maker to turn green is Jeep. Its Renegade Concept, also shown at Detroit, is a roof- less two- seater that is powered by two 200kW electric motors, each powering an axle and each fed by a lithium- ion battery pack. On batteries alone the Renegade is good for a 65km range. A clean 85kW three- cylinder Bluetec diesel engine is installed to boost range to 640km. The Jeep goes a step further than most with its environmental message, using environmentally friendly body structures and paints.
Manufacturers of traditional, large fourwheel drives elsewhere are examining their green conscience. While Land Rover has experimented with electric Land Rovers before in engineering backrooms, it has just recently unveiled its first hybrid concept vehicle.
The Land Rover LRX Concept has been positioned as a compact luxury hybrid 4X4 and, it is also expected for production by 2010 — although probably with a conventional powertrain. Yet with its showcase hybrid LRX Land Rover says it could achieve an emissions level of 120g/ km using the technology focussed on energy- saving.
The LRX has a relatively conventional 2.0- litre turbo- diesel able to run on biodiesel, and operates in parallel with an electric motor, which Land Rover calls an Electric Rear Axle Drive ( ERAD). The diesel engine drives all four wheels, while ERAD drives the rear wheels at speeds up to 32km/ h.
The LRX powertrain was designed so that it will be able to run the ERAD on a lithium- ion battery pack in traffic, with an integrated starter motor and generator firing up the diesel when the LRX is up to speed. Conversely, as the vehicle stops the system shuts the diesel down.
Land Rover’s proprietary Terrain Response program has five modes in the LRX including a new one called Eco mode, which ties in all systems to provide optimum fuel economy.
To cover the enormous costs of developing new clean technologies, many car manufacturers are collaborating in joint efforts with government and other organisations.
One such company is Volvo, which has entered into a $ 2 billion joint research venture to develop plug- in hybrid cars with the General Motors- owned Saab, Swedish electricity provider Vattenfall, the ElectroTechnological Centre and the Swedish government. The joint venture will see 10 plug- in hybrids field- tested in Sweden.
Volvo unveiled a plug- in concept car with its series hybrid, the C30 ReCharge Concept, last year. The Volvo ReCharge Concept is a series hybrid with a lithium- polymer battery pack integrated into the boot. Four electric motors, one at each wheel, provide propulsion with a claimed range of 100km and a top speed of 160km/ h. Re- charge time is three hours. The 1.6- litre Flexifuel four- cylinder engine powers a generator to supply power to the wheel motors when the battery power gets low.
Even though Toyota and Honda are already selling their second- generation of petrolelectric hybrids, they cannot run on electric power alone for any meaningful distance and are not plug- in hybrids.
However, it won’t be long before other major car manufacturers start to deliver on their promises for a next- generation clean car.
The first is most likely to be Chevrolet with its Volt, a plug- in hybrid that is scheduled for production by November 2010. The Volt is well into its development phase, with preproduction mules already out on the roads testing components.
The Volt is, strictly speaking, a series hybrid that relies on a range extender — a 1.0- litre three- cylinder turbo internal combustion en- gine that runs on E85 bio- ethanol — to charge the batteries for distances longer than about 60km. Chevrolet is allowing for fuel cell technology to be incorporated into the Volt, but development focus appears to be on getting the petrol/ electric hybrid to market.
In its laboratories, GM is well into durability and life- cycle testing the Volt’s lithium- ion batteries from two battery suppliers. Because battery performance deteriorates with age, the Volt engineers are working to ensure that the battery pack has a minimum 64km range on its battery pack after 10 years and 240,000km of use.
There is still much work to do to refine and improve the technology for mass- produced clean cars, but the automotive world is getting very close to delivering on its promises.
Concepts: Different manufacturers have different ideas. Clockwise from above, Jeep’s two- seater Renegade, Land Rover’s LRX, Volvo’s plug- in ReCharge and Cadillac’s Provoq