Lexus: The hybrid debate blog

People are rushing to buy hybrids because they believe that if everyone were to drive more efficiently then the environment would benefit hugely. However, they’re failing to take into account the massive amounts of energy required to build a car in the first place, and to dispose of it at the end of its life. These “embedded” costs may mean that a future full of hydrids is not feasible, or even desirable.

Building any mechanical or electrical system requires energy. In general, the heavier and more complicated the system, the more energy you require. So to calculate the total “footprint” of a car you must include a proportion of the energy involved in mining operations, blast furnaces, rolling mills, lathes, presses and robots. To this can be added the heat and light used in design offices and factories; and the fuel used by ships and trains to deliver components and finished vehicles. And so on.

A recent study by Esther Dudek at Lancaster University showed that the manufacture of a conventional family car takes around 15,000 kWh of energy and the emission of more than two tonnes of CO2. This figure, which is equivalent to the emissions generated by burning 1,000 litres of diesel, excludes the delivery costs of components and the finished vehicle; and energy used at the point of sale. It also excludes the cost of scrapping or recycling the car, which, according to other research, will typically release emissions equivalent to another 1,000 litres of fuel.

Hybrids are intrinsically more complex than conventional cars, so their embedded costs are likely to be higher. They take more energy to build, and their disposal is trickier too, thanks to the presence of a battery.

More significantly, they are likely to have a shorter average life-span than their conventional rivals. Simple cars are easier to maintain, need fewer spare parts and are generally lighter. If you add features such as air conditioning, power steering, CD players, multi-speaker hi-fis, catalytic converters, airbags, electric windows, heated seats and all the other extras of modern motoring, you increase both fuel consumption and embedded energy, and you raise the likelihood of the car being scrapped when some of these systems fail. Adding yet more complexity in the form of a generator, motor, battery, inverter and several microprocessors is unlikely to make the car last longer.