No replacement for internal combustion engine on horizon

The hallmark of a good design is longevity and the internal combustion engine has survived decades with only relatively minor modifications. But the threat of peak oil and increasing legislation aimed at tackling climate change is forcing the motor industry to start seriously examining alternatives to fossil fuel.

The dominance of conventional petrol and diesel powered cars has made motor manufacturers reluctant to invest sufficient resources on developing attractive alternatives, which in turn maintains the old order. The car industry has been trapped in a self-reinforcing loop. The imminent launch of Nissan’s Leaf electric car –  the first five door family hatchback to be produced on a large scale, could change that.

The shift towards low emission alternatives is not only about climate change. There is little doubt that the price of fuel will rise sharply over the next few years. This prospect has arguably done more to spur the search for alternatives than any green agenda.

Stephen Glaister, director of the RAC Foundation, says: “A shift away from a reliance on petrol and diesel will not only be good for the planet but will also help to retain the personal mobility so many of us rely on.” For the motor industry, the discovery and development of a realistic alternative to the internal combustion engine is becoming a matter of survival.

The role of governments is crucial to this process. The market will eventually dictate which technologies emerge triumphant. But seed funding, tax breaks and regulation designed to encourage alternatives are essential to kick-start the process.

As yet it is unclear what might supplant the internal combustion engine. Each contender has huge difficulties to surmount and none is ready to be mass produced – the crucial development that would drive down costs and result in wide-spread use.

More efficient conventional cars

The fundamental design of cars has changed little over the years. They are large boxes powered by an internal combustion engine and running on rubber tyres. This design has, of course, become more efficient over the years. But manufacturers believe that there is still considerable room for improvement.

The European Union is planning to impose extra charges on high-consuming cars. It wants to get average emissions down to 130 grams of carbon dioxide per kilometer from 153 grams at the moment. The eventual target is 95 grams. From 2015, manufacturers will be ‘fined’ for every car they produce that emits too much carbon dioxide.

There are numerous ways to reduce fuel consumption. These range from low-rolling resistance tyres and better aerodynamics through to ambitious concepts such as regenerative braking –which captures the energy generated when braking by installing a flywheel – and downsizing engine capacity with turbochargers.

However, the trend to fit cars with more gadgets and safety equipments has resulting in an average increase in fuel consumption. As long as cars continue to be seen as a status symbol, this will be hard to reverse.  

Moreover, engineers believe that there is a theoretical limit to how clean they can make internal combustion engines, which is thought to be around 70 grams of carbon dioxide per kilometre. Even if every car on the road was able to achieve this state of engineering perfection tomorrow, it would probably not be enough to reach the targets for green house gas reduction that most governments are now aiming for.


Growing fuel rather than pumping it out of the ground is an enticing prospect. Most cars don’t even need to be modified to run on a fuel mix that includes 10% biofuel. This appeared to be an easy way of reducing carbon emissions and EU legislation was drawn up stipulating that 5.75% of fuel should be sourced from renewable sources, rising to 20% in the longer term.

However, the unintended costs now appear to outweigh the benefits and biofuels are rapidly falling out of favour.

For starters, biofuels are around 50% more expensive than the petrol that would provide an equivalent amount of energy. Moreover, most biofuels are produced from food crops and in a world with only finite resource of arable land that threatens to push up the price of food.

But most worrying is the threat that biofuels appear to pose to biodiversity. An EU report found that vast swathes of Malaysia and Indonesia have been deforested to grow palm oil for fuel. This was negating much of the benefit in the reduction of greenhouse gases from petrol and diesel. 

There has been already been a retreat from the legislation in the face of these concerns. The UK government lowered the target set out by the EU to 3.25% in 2010, with a gradual increase to just 10% in 2020. In addition, the 20% tax incentive for biofuels was scrapped in April 2010.

It would appear that the future for biofuels lies with non-edible biomass such as seaweed, algae or agricultural waste products. But so far no such fuel has been produced in commercially viable quantities.

Fuel Cells

Fuel cells typically convert hydrogen into electricity in a very clean process that produces only water and a small quantity of other by-products.

However, hydrogen can only be stored in liquid form. This requires compression and, because the chemical is so flammable and volatile, the use of heavy containers. Early fuel cell cars have been designed with the hydrogen store on the roof to reduce the chance of an explosion in the event of an accident. Although major car manufacturers have produced several generations of cars powered by hydrogen, they are still not commercially viable.

The cost of producing the hydrogen in the first place is also prohibitively high. Massive quantities of energy are lost in process, which tends to negate the efficiency of the engines.

A recent report by the RAC Foundation was particularly gloomy about the prospects for hydrogen powered cars: “It is unclear how the simultaneous development of

infrastructure, renewable hydrogen and provision of vehicles at an economically viable rate will be achieved. This uncertainty is partly due the fact that there are no hydrogen vehicles available in UK showrooms today.”

Electric and hybrid cars


Undoubtedly, the most promising alternatives to the internal combustion engine are electric or hybrid vehicles. Even without using sustainably sourced electricity, electric cars would greatly contribute to carbon reduction from transport.

A report commissioned by the British government and published by the Centre of Excellence for Low Carbon and Fuel Cell Technologies published in October 2008, concluded that electric and plug-in hybrid electric vehicles offer potential carbon dioxide reductions of 40% – even on the UK’s current electricity grid mix – when compared with conventional petrol or diesel cars over a full life cycle. Moreover, as more electricity is produced by wind power there would be even bigger reductions of carbon dioxide, especially as electric cars tend to be refuelled at night when there is spare power.

Already some countries are adopting ambitious targets for the number of electric vehicles they want to see on their roads. The Irish government wants 10% of all cars sold by the end of the decade to be electric. It is also rolling out an extensive program to install charging points by the beginning of 2012 with 500 planned for Dublin alone. 

Supporters of the programme point to the fact that running costs of electric cars would on average cost €1,000 less a year to run than conventional vehicles. Nissan is hoping to sell 300,000 of its Leaf cars globally by 2014 on the basis of such statistics.

The biggest obstacle to these goals are the costs of the cars themselves and concerns about range. The Nissan Leaf will be sold for $32,780 in the U.S, far higher than comparable compact cars. The battery pack alone costs $10,000.

Although most journeys are just a few miles, and electric cars have a range of around 100 miles, potential buyers still worry about their range.

Austyn Smith, professor of transport studies at the University of Westminster, points out that despite being on the market since the 1990s, electric cars have not made the breakthrough. He says: “Currently there are a total of 8,000 pure electric vehicles on the roads of the UK, representing less than 0.1% of the UK’s 26 million cars – hardly a ringing endorsement by consumer of the current offer from the industry.”

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