Road vehicles cause a sixth of man-made carbon emissions. This, along with the high cost of fuel, are the main driving forces behind manufacturers looking to develop cleaner, more efficient cars which use alternative propulsion methods. Jon Norrey examines the ones vying for pole position.
Whilst sitting still in yet another traffic jam, we’ve all wondered what it would be like to speed through the air in a flying car; soaring over any obstacles that might once have blocked our journey. Some of the more ambitious members of the automotive industry are even working on this; but the majority are concentrating their efforts on an arguably more important, if less interesting, car of the future.
Electric, hybrid, and alternative fuel cars, are the ones on track to becoming the future of automobiles. And the ultimate winner will be the one that can offer the best combination of cleaner, cheaper and more readily available fuel – but this race has only just begun, and the road ahead may get a bit bumpy; however, the auto industry is smoothing it out as much as possible with investment of over £60 billion a year dedicated to research and development of these machines.
A lot of effort has gone into reducing greenhouse gas emissions from fossil fuel-powered cars over the years, with some success, but many now agree that the main problem is the fuel rather than the vehicle. While more efficient engines and catalytic converters – which reduce the toxicity of pollutants – have helped, burning fossil fuels like petrol and diesel is always going to result in a lot of environmentally unfriendly substances coming out of the exhaust. Over 95% of which is carbon dioxide (CO2), the most abundant ‘man-made’ greenhouse gas. The average car pumps out 5.1 tonnes of it per year.
“Air quality is greatly compromised by traffic emissions,”says Andrew Clark, environmental assessment and management lecturer at Salford University.
He adds: “Transport constitutes over a quarter of greenhouse gas emissions and around 36% of our energy use in the UK, so more than a third of energy we use goes to burning fuel in private cars, of which there are around 30 million on the road. This is very important in terms of carbon emissions, but we should also remember that very harmful pollutants other than carbon are being produced too, such as oxides of nitrogen and particulate matter.
“We have pollutant levels that shouldn’t be exceeded called limit values. The UK is currently exceeding the limit value for oxides of nitrogen [molecules containing nitrogen and oxygen] in many urban areas, such as Manchester and London.
“On top of that, research has actually found adverse effects such as respiratory illness and reduced life expectancy at levels below those limit values that we’re already exceeding!”
With CO2, oxides of nitrogen and various other pollutants reducing air quality, causing illness and contributing to climate change, it seems to be in everyone’s best interests to consider the alternatives. With this in mind, the UK government has offered £900 million in grants for the development of ultra-low emission vehicles, for which it wants the country to be at the global forefront.
In November, Deputy Prime Minister Nick Clegg, said: “The UK’s automotive industry has undergone a renaissance in recent years and we have the potential to emerge as a trailblazer in the development, design and manufacture of green cars.
“We’re doing well compared to our European competitors, helped by a buoyant UK car market. But, if we’re to stay ahead we need to secure the UK’s position as both a global leader in the production and adoption of low carbon vehicles.
“We need to see more people who live in Britain driving these cars and enjoying the lower running costs they can bring.”
While our government recognises the importance of creating and driving these vehicles, it’s other nations – mainly Japan – who are leading the charge.
The Nissan leaf is the top selling electric vehicle in the UK, and has sold 100,000 units worldwide. Nissan spokesperson Richard Murphy says: “The benefits electric cars have over other vehicle types are that they are cheaper to charge and run. If you live in an area with congestion charges they are normally not charged these due to the near zero CO2 emissions, which also means there’s no road tax, as well as being a lot better for the environment.”
The Leaf, along with other electric cars, boasts zero emissions at the point of use. But the electricity to charge the batteries still typically comes from power stations, so to think of it as entirely emission-free fails to take into account the full picture. While it greatly varies depending on location and means of electricity generation, electric cars produce on average around half the emissions of their fossil fuel-powered counterparts.
But there are a few drawbacks. The battery technology, while improving, is heavy, expensive and only offers a range of around 100 miles – and if you’re running out of juice a long way from home, charge points are extremely scarce. On top of that, the vehicle can take up to 13 hours to fully charge when plugged into a domestic socket.
Electric vehicles are also almost double the initial cost of similar conventional cars and, once bought, only manage to retain around 20% of their value after three years. Despite this, research shows that by the end of 2014 the number of electric cars on the road will have doubled to more than 700,000.
A hybrid car, as its name implies, uses a combination of different propulsion methods; usually a conventional petrol-powered motor, as well as an electric motor and a battery. There have been over seven million hybrids sold worldwide, with manufacturer Toyota providing 80% of them.
Toyota spokesperson, Nathan Jones, says: “Hybrids offer the best of electric and petrol vehicles, like low emissions and no road tax, and you don’t have to spend hours charging the batteries as they charge automatically while driving. The car also decides which is the most efficient power method at the time and switches between the two which means they offer a similar performance to normal cars.”
He adds: “We estimate that hybrids save about 40% in running costs. ”
Toyota claims their hybrids release 37% less CO2 than comparable diesel cars and have prevented the emission of 34 million tonnes of the greenhouse gas. However, with initial costs of around 25% more than similar conventional cars, and higher maintenance costs due to the extra complexity of the dual propulsion system, many experts claim that hybrids are merely a transition technology before we properly utilise alternative fuels like hydrogen and biofuels.
Toyota are also at the forefront in hydrogen-power, with the first mass-production vehicles set to go on sale next year.
The cars will be powered by hydrogen fuel cells which work by ‘stripping’ electrons off hydrogen stored in the cells and using them to create electricity. The used hydrogen then combines with oxygen from the air to form water, which is released as a vapour. This is the only emission.
While the generation of electricity to power the car works similarly to battery-powered vehicles, hydrogen power offers the kinds of benefits that are more likely to satisfy the consumer, such as the ability to refuel in under five minutes and a range of around 300 miles. It will therefore offer all the comforts of a conventional vehicle, with none of the emissions out of the tailpipe. Perfect, right? Well, not exactly. Once again, you have examine the full picture of how the fuel is produced.
Hydrogen is almost exclusively obtained from natural gas (methane). The process involves reacting the methane with water which releases not only hydrogen, but our old foe: carbon dioxide.
Because of this, studies estimate that the actual emissions per vehicle add up to only slightly less than hybrid vehicles; however, various other methods of hydrogen production are being explored which have the potential to cut the emissions by more than half. These include: ‘gasification’ – converting coal or biomass into gaseous components and using various chemical reactions to greatly improve efficiency; electrolysis – using an electric current to split water into hydrogen and oxygen (which could employ the use of low-carbon renewable energies); and high-temperature thermochemical water-splitting – which uses high temperatures from nuclear reactors or focussed sunlight to split water.
Some have voiced concerns over the storage of pressurised hydrogen in the cars, which is highly explosive when ignited. But experts assert that it is actually less dangerous than the highly-combustible fuels we currently use – so we’re unlikely to witness any smaller scale, ground level Hindenburg disasters.
The more pressing issue for the consumers is the lack of infrastructure; hydrogen refill pumps are currently only available in California, so the cars will only go on sale there, but if successful, we could see rapid worldwide expansion of the technology.
The last of the competitors are biofuel-powered cars. Biofuels are fuels made from living organisms – like plants and algae – which absorb inorganic carbon and turn it into organic carbon – basically, they take in useless and potentially harmful carbon substances (such as CO2), and give out useful carbon substances which we can burn as fuel.
Obviously, burning this fuel creates the useless and potentially harmful carbon substances again, but, in theory, it balances out as the organisms absorb it all again and turn it back into useful carbon – so it’s ‘carbon-neutral’. But in practice it isn’t doesn’t quite work out that way as growing the organisms requires various uses of fossil fuels; however, studies have shown that greenhouse gas emissions can be reduced by up to 90% by utilising biofuels.
Biofuels are already used to great effect in the US and Brazil, and the most appealing aspect about them to many is that they can go into our standard fossil fuel-powered cars. Diesel cars require no modification to use them, and petrol cars can be modified relatively cheaply. In fact, it is common even now to see fossil fuels blended with a small percentage of biofuels to reduce the cost and lower emissions, and this method could open the door for fossil fuels in our future vehicles, albeit in smaller doses.
The drawbacks of biofuels are that they provide less power than fossil fuels as they store less energy, which reduces vehicle performance and requires more regular fill-ups. But the main concern is one of an ethical nature: should we be using crops for car fuel when instead they could be used to feed starving people around the world?
Given that biofuels are usable in the standard cars we all know and love, this may give them the edge over their rivals. However, the auto industry is always developing and expanding; it could, at any time, give a significant boost to one of the aforementioned competitors, or maybe even offer a short-cut to the chequered flag to one we didn’t even know was in the race.
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