Electric vehicles (EVs) have become a subject of focus for many leading automobile companies as well as newer, lesser-known start-ups. Be it Tesla, Audi, Citroën, or even recently the Turkish company TOGG, massive efforts are continuously being put into the advancement of electric vehicles to maximize their range, boost their performance, and introduce them to a broader market segment. As presented to the public, electric vehicles hold the promise of a green future with silent roads, no harmful gas emissions that lead to health problems and global warming, and no danger of oil depletion. While this is, in fact, the long-term goal, the current situation is far from being that utopian, at least not on a global scale.
Substituting conventional internal combustion engine vehicles with their electric counterparts might mitigate the problem of harmful environmental impacts from the automobile sector, but that is not always the case. In fact, in some scenarios, it may lead to the total opposite, and the ‘green cars’ may actually do more harm than good.
This article strictly refers to battery EVs; that is, the vehicle operates by charging its battery, which then supplies electricity to the motor, which in turn drives the wheels. Unlike conventional vehicles, EVs do not require a bulky engine or a complex transmission system; instead, they rely on a simple single-stage gear drive with a forward and reverse mode. A typical electric vehicle comprises a few main components:
- Charger: Supplies DC (Direct Current) power to the battery from the grid’s AC (Alternating Current) electricity
- Battery: Typically lithium-ion (Li-ion), a bundle of battery ‘cells’ fuels the vehicle.
- Controller: Monitors the overall performance of the vehicle and is responsible for transmitting pedal signal to the inverter.
- Inverter: Converts the battery’s DC signal to AC to drive the motor, with a frequency and amplitude assigned by the controller.
- Motor: Draws AC power from the inverter and rotates the wheels through the designated drivetrain.
During acceleration, the pedal’s pressure is translated by the controller into the corresponding motor AC frequency, and the wheels turn at the desired speed. During deceleration, the motor acts as a generator whose output is supplied back to the battery, a process called regenerative braking.
Clearly, EVs possess fewer mechanical parts, which are often also lighter than those in conventional vehicles, and produce no harmful emissions, with relatively little noise during operation. The decreased weight of the vehicle itself implies less energy consumption due to decreased power required to move the car, thus increasing its operational efficiency. However, a vehicle’s total environmental impact, or carbon footprint, is not limited to its operation only, but its production and ‘fuel’, in this case electricity, as well. When these factors are taken into consideration, EVs no longer exhibit a foreseeable immutable advantage from an environmental point of view.
When comparing EVs to conventional gasoline or diesel vehicles, there is not much difference in terms of the production of the actual body of the vehicle, that is, if the battery is excluded. The battery of an EV, or the Li-ion battery, requires much energy and involves mining for various metals such as Lithium, Nickel, and Cobalt. In contrast, an internal combustion engine involves many mechanical parts that require a more complicated manufacturing process, but not as much energy as a standard EV battery. However, the electricity used to fuel an EV is where things get a little more uncertain. Regions such as Europe, for example, have already shifted significantly towards renewable energy resources to cover the electricity demand.
This picture changes, though, in many parts of the world, including Lebanon, where conventional power plants with an extremely high carbon footprint are still the sole producer of electricity, and in which the negative impact of EVs outweighs the positive. Thus, the overall life-cycle carbon footprint of EVs compared to conventional vehicles is not a simple matter of generalized pros and cons. It depends mainly on the region in which an EV fleet is being incorporated.
Taking into account the battery size, electricity source, operating conditions, and the yearly mileage, one can get a rough estimate of how long a certain EV will take, if ever, to exhibit an environmental advantage over a gasoline or diesel vehicle. Such analyses might lead to one of three cases: either the EV is clearly better, is better up to a certain battery size or mileage, or will never be better than a conventional vehicle due to the method of electricity production in that particular region.
There is no doubt that electric vehicles are an integral element of future transportation systems. However, such systems will have to integrate cutting-edge technological solutions to the many controversial issues surrounding EVs. Manufacturers still have a long way to go when it comes to optimizing batteries, obtaining clean electricity, and producing an economically suitable product for users. It is not only a matter of addressing each issue alone, however; EVs of the future will be but a part of a much larger transportation network of interconnected vehicles, infrastructure, and data sources.
From a sustainability perspective, continuing to rely on the vehicle technology as we know it today may not be the most efficient option for green cities. Such a prospect will have to involve the concept of “Smart Cities“, which are, in essence, complex systems comprising a multitude of sensors and computers to perform intelligent, real-time, optimization and management of future cities for vehicle navigation, passenger service, and energy management. Research in smart cities has accelerated during the past decade, and several cities have integrated smart technologies already. Nevertheless, there is still much room for improvement, and tremendous efforts need to be put in order to achieve the true goal of smart cities.