Véhicule et pollution - étude en anglais

Hybrid Vehicles

Introduction

Transport has become a primary source of pollution. Motor vehicles, massively developed and disseminated during the twentieth century were in fact designed before the oil shock of 1973 on criteria of performance, comfort, and cost, and after that date, adding a goal of low power consumption. If 1973 was the shift in the direction of efficiency, it does not take into account the issue of harmful emissions. This will be addressed in late 1970s in the United States with the first unleaded fuel in California.

1. Zero emission vehicles

Before going any further, I would like to deal with zero emission vehicles. Nowadays, there are no such vehicles. CO2 emissions have become, because of their proven role in global warming, the main environmental indicator of the automotive industry.

In fact, these CO2 emissions do not mean much because they simply do not take into account emissions related to the manufacture, assembly and transport vehicles prior to purchase, not to mention the emissions from recycling (75% a car is recycled at the end of life) or landfilling of what remains of end of life vehicles.

A car indeed requires an average of 30 tons of raw materials during its construction. These raw materials are extracted from the ground, transported and processed, high CO2 emitting activities. From these raw materials, we will manufacture parts. These parts are then also transported, sometimes across the world, to be assembled in the factories of automakers. And then, the assembly and final transportation of vehicles also produce CO2.

All this is what is called "gray emissions " of CO2, that is to say the hidden emissions that are not directly related to the use of the car but nevertheless represent a significant share of total emissions from cars, what can be called the "carbon balance of the car".

For example, for an automobile officially emitting 180 g CO2/km, total emissions would in fact be of 306 g CO2/km!

Icing on the cake, it now appears that by making efforts to lower the rate of CO2/km, manufacturers sacrifice the rest and actually have vehicles that pollute more! Because CO2 is a pollutant from all other automobile (No2, particles, CO, benzene, PAHs, etc.).

2. Hybrid Vehicles

A hybrid car is a vehicle that uses two types of technologies for energy. This usually refers to an automobile that has both conventional gasoline engine as well as bank of batteries and that shares the demand for power between these two sources. One source might be the main power source with the other serving as a backup, or the vehicle might uses one source in certain situations and the other in different situations.

Almost all the time, “Hybrid car” refers to the combination of gasoline engine with an electric motor. There are several families of hybrid cars. We differentiate them by:

- Proportion of secondary energy available

- The type of secondary energy

- The duration of work of the secondary energy

- Simultaneous

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