Each morning, I have difficulty breaking into the line of cars heading into Cork on the Bandon road, and the same thought usually occurs to me: why are we all regularly commuting short distances in cars that are half or three-quarters empty, burning up scarce petrol and polluting the air? Why don't we commute in little energy-efficient, non-polluting two-seaters? Why are automobile manufacturers not making such cars for the mass market? Some answers were provided by Victor Wouk in an edition earlier this year of the Sciences.
The automobile was born in the late 1860s and brought to the mass market by Henry Ford in 1908. By the 1950s, cars had evolved into large, polluting, petrol guzzlers, but this trend changed as people became conscious of air pollution and, particularly, when petrol prices soared in the 1970s. Cars then became smaller, cleaner and more fuel efficient, and if this rate of change had continued, we would all be driving around in super-fuel-efficient and, probably, battery-powered cars. As things stand, though, while the average car is reasonably non-polluting and fuel efficient, increasing numbers of petrol-guzzling luxury cars and sport utility vehicles are being sold.
Any automobile propulsion system must supply enough continuous power to allow the vehicle to cruise the open road and climb a hill at reasonable speed. The internal combustion engine was invented in the latter half of the 19th century and fairly quickly became the popular propulsion system. The engine develops power from the explosive burning of petrol in air, the energy of which is transferred to the automobile's wheels. Petrol is a very compact energy source, and the internal combustion engine has been refined to a high degree.
The penalty for exclusively relying on petrol-burning engines has been twofold: pollution and scarcity of petrol. The burning of petrol releases lead, carbon-monoxide and dioxide gases and complex hydrocarbons into the atmosphere. Lead is a serious pollutant that can damage the brain, and the gases and hydrocarbons cause smog in cities and enhance global warming. Also, petrol is derived from oil formed in the earth, in finite amounts, over hundreds of thousands of years. Sooner or later, the reserves will run out.
Two approaches have been taken to solving the problems. One was to make the internal combustion engine as clean and efficient as possible, the other to develop an alternative power source for the automobile. The first approach has been quite successful. The average car today emits as little as 2 per cent of the pollution it would have emitted 30 years ago, and it is much more fuel efficient.
The petrol-powered internal combustion engine is targeted for extinction, however. Although it is unlikely that internal combustion will be supplanted in the near future, the automobile manufacturers are investing billions of dollars in developing radical technologies to power automobiles. Wouk argues that there have already been enough inventions to make hybrid electrical vehicles feasible alternatives to conventional internal combustion engines. He argues that decision-makers have not exploited the development because of their reluctance to introduce "transitional" technology, preferring to wait, unrealistically, for a mature but revolutionary new technology.
In the early days of the automobile industry, petrol-powered vehicles were in the minority. At the start of the 20th century, three quarters of the cars sold in the US were electric vehicles and steam-powered cars. The steam-powered car was modelled on the steam engine, and it worked well: good acceleration, mature technology, high speed and good range. It had one disadvantage: it took more than 10 minutes to build up enough steam pressure to get going.
Early electric cars were non-polluting and elegant, and they started instantly. They were powered by large batteries and had a range of about 30 miles. They were particularly popular with women and with companies that used delivery vans. Early petrol cars were noisy and unreliable, and required strenuous hand-cranking to start them up. The invention of the starter motor allowed the petrol engine to be started by turning a key, and this, contrasted with the slow start-up of the steam car and the limited range of the electric car, turned the market in favour of the internal combustion engine.
Wouk argues that the most reasonable future for the automobile is the hybrid electric car. This combines some of the attributes of an electric car and some of those of the internal combustion engine. A small internal combustion engine might run a generator to recharge the batteries of an electric car, for example. He developed and tested such a car in 1974, exceeding the standards of the Clean Air Act of 1970, standards it took the conventional engine another 12 years to match. Such a hybrid power plant could operate a car at 80 miles to the gallon of petrol, at reasonable speeds and emitting very little pollution.
Why are automobile manufacturers not picking up on the hybrid electrical car? Wouk says the industry is enormously resistant to change, reinforced by the fact that large cars are far more profitable than small ones. Each sport utility vehicle makes up to £10,000 profit for the manufacturer, whereas the profit on small cars is almost negligible - something to ponder when you are stuck behind a large four-wheel-drive vehicle on its way home to a semi-detached house in suburbia.
William Reville is a senior lecturer in biochemistry and director of microscopy at UCC