Driving Change By Rachel Sullivan

Transport emissions account for a significant - and rising - percentage of greenhouse gases. Despite their environmental impact and the recognition of the need to reduce transport emissions, cutting them is a challenge for policymakers, partly because car ownership is symbolic of wealth and success in modern societies, and because globalisation and international trade have resulted in a substantial increase in freight transport around the globe. Both play a key role in the huge increase in emissions in recent decades.

A large part of the solution involves behavioural change and an important part of making transport more sustainable involves encouraging people to walk, ride or use public transport. However, overcrowding and limited access to public transport services in outlying parts of sprawling cities means that for the foreseeable future, at least, Australians will continue to rely heavily on their cars.

"Transport planners need to come to grips with a large portion of the motoring public who prefer or are dependent upon relatively inefficient mobility such as the private automobile, and a transport system that operates in a more sustainable fashion when active transport and public transport are used in large proportion," says Professor Simon Washington from the School of Urban Development, Faculty of Built Environment and Engineering at QUT.

"A well-planned future will preserve or improve travel choices and mobility to the extent possible and will harness economic tools, land-use and urban planning tools, employer-based policies, and a range of technologies (including greener cars), more seamless travel planning, telework related technologies, and more efficient methods for sharing information.

"These tools must be exploited to make efficient travel modes preferred to less efficient ones, with efficient modes also supporting a variety of complex travel patterns observed across both urban and suburban households," he continues. "A sustainable transport system is likely to require bold governmental leadership, fundamental re-thinking of age-old land use patterns of growth, and innovative public-private partnerships." (Read more from Simon Washington in the accompanying article "Travel Plans".)

So with people looking set to continue their love affair with the car for the foreseeable future, the development of environmentally-friendly vehicles is a priority for many manufacturers and users. This will have particular significance with market-pull, when consumers will demand that all vehicles comply with increasing 'minimum' standards (at least) for fuel consumption, efficiency and environmental compliance.

In Germany, the car industry is working with the government to get a million electric cars on the road by 2020 - equivalent to one in four cars sold. Unsurprisingly, Australia is some way behind Europe, but with support from initiatives such as the Green Car Innovation Fund, and a growing recognition that eco friendly vehicles can be attractive too, change is coming.

There are currently three mass market hybrids on the road in Australia: the Toyota Prius, Honda Civic and Lexus 400h, as well as a number of custom-made, modified, prototype and limited production electric vehicles such as the Blade and the i-Miev, which is being trialled by various government departments.

Making vehicles more eco friendly is about more than reducing emissions, however. As evidenced by the extremes to which oil companies are now turning to extract oil, such as the infamous deep sea drilling project in the Gulf of Mexico and oil sands extraction projects in Canada, sooner or later oil will run out, and no one wants to be left without a viable product on the market when the inevitable happens.

Mercedes-Benz is celebrating its 125th anniversary next year and has arguably been at the forefront of vehicle and engine design since first inventing the combustion engine.

"We have always focused on reliability and quality, and these were later followed by performance and safety," comments Hans Tempel, president & CEO at Mercedes-Benz Australia/Pacific. "More recently as society has become sensitive to the environment, Mercedes-Benz and parent  company Daimler have also become concerned about both our corporate footprint and that of the cars we make. We see this as an opportunity to lead the way for the auto industry.

"The company has been working on the issue of emissions-free driving since the 1970s when we began looking at technology that is not based on combustion engines," he says. "We don't know how much longer oil supplies will last, but eventually it will become a scarce product. What technology will replace [the combustion engine] we don't know."

Like other industry experts, Tempel believes the best option currently available is hydrogen fuel cells that generate energy without any emissions at all, although fuel cell technology is still developing and there is a worldwide shortage of refueling infrastructure. At the moment, hydrogen is commonly produced using steam that reacts with methane and converts it into hydrogen and carbon, although it can also be produced from water through electrolysis.

The hydrogen can then be stored in a fuel cells where a chemical reaction inside the cell - usually between hydrogen and oxygen - generates electricity for the motor with only water vapour coming out of the tailpipe.

"We are in the process of using this technology in a number of prototype buses, trucks and passenger cars and are at the stage of looking at producing the first vehicles in a small production series that will be marketed in Germany, Japan, Singapore and the US," says Tempel - countries that have publicly accessible hydrogen filling stations. There are a number in the US, especially California, and in tech-savvy countries like Singapore, whose small size and supportive, relentlessly forward-thinking government means that one or two filling stations are enough to service the whole country.

Australia is a different matter, with very limited hydrogen refueling infrastructure. "The way things stand, it is hard to imagine that there will ever be a hydrogen filling station in the middle of the outback, or indeed in many other places," comments Tempel, adding that although hydrogen fuel cells are currently the most desirable outcome, cost issues and the lack of infrastructure mean that Mercedes is covering its bases and looking at the challenges of emissions-free driving using other technologies.

"Just as we need to rethink our ingrained notion of the one type of car to suit all purposes, from commuting to offroading, the fuel cell might not be the optimum choice for all forms of transport anyway. There may be no one solution that gains traction across all market sectors.

"We believe there is scope for improving the combustion engine considerably, and reducing carbon dioxide emissions in the process. It may well prove that there is no single technical solution, and that the sustainable transport mix may include petrol, diesel, rotary and electric engines."

Unlike the US and EU, Australia has only an industry agreement about reducing emissions and fuel consumption. Without regulation, which in the EU is demanding emissions of less than 122 grams per kilometre by 2020, it is really up to manufacturers to lead the way.

Diesel technology is already much more efficient, Tempel says, offering more power and greater levels of performance for less fuel consumption when compared with a petrol engine. And although most diesel is still oil-based, the growing availability of plant-based biodiesels will ramp up its green credentials in the future.

"[Making personal transport more sustainable] also involves an educational component, where people need to ask themselves whether they need a big 500 horsepower engine or whether the same level of luxury and comfort can come with a smaller engine.

"For example, the 2.1 L S250CDI model is the first luxury car to use less than six litres of fuel per 100 km with emissions of 149 grams of per kilometre in standard test conditions."

Like other manufacturers, Mercedes-Benz is also exploring different hybrid engines. There are several types available, from those whose electric battery is recharged by the energy captured during braking, to those that are plugged in to a charger, to those whose depleted battery is simply swapped for a fresh one.

"We do offer a hybrid, however it is not currently sold in Australia because of technical and cost issues associated with producing a right hand drive model for a relatively small market," he says. "However, we are working towards providing a hybrid version of each model and also at producing electric models that you can plug into the grid overnight or at a parking station."

Before electric vehicles (EVs) really take off, however, Tempel argues that there are a number of issues to be resolved.

"From a safety perspective, which has always been central to our design ethos, electric cars are really quiet when they're operating which means pedestrians and drivers of other cars can't hear them, potentially leading to accidents.

"We are looking at ways to make them more obvious, whether that means making them artificially sound like a V8, or giving them the equivalent of a ringtone; people would find it hard to miss a car that sings theHallelujah chorus or cries like a baby as it drives down the street," he laughs.

Another significant issue to overcome is battery technology that allows them to be rapidly recharged, and to store more charge when full. CSIRO's revolutionary Ultra Battery, which integrates a lead acid battery and supercapacitor in one cell, produces oodles of power and has a long life, and has great potential in next generation vehicles.

There are a number of EV recharge concepts currently being trialled around the world, including recharge stations that can take anywhere from 10 minutes to eight hours to recharge a car (see Electric Avenue box), and  battery swap services. These are faster but will require standardisation of batteries so a driver can reload where convenient, rather than only at nominated facilities.

"Standardising batteries would also have an impact on design and the functionality of the car, and people are used to being able to express our individuality," says Tempel. "As a luxury brand, we don't ask our customers to compromise what they have learned to like, and to take away the values of safety, comfort and convenience.

"Instead, we ask customers to enjoy everything they value at a lower environmental cost than in the past.

"Leadership is not about being the fastest driving in a circle," he says. "In this case it is about taking the responsibility to stand up and show people that driving an electric car or a smaller car withas much power as they need can be sexy too."