Evaluating the environmental impact of electric cars
Sinai Rhodes
The internal combustion engine (ICE), the brain of the automobile, was first designed by Gottlieb Daimler in 1885, subsequently improved upon and patented by Karl Benz in 1886. 1 The electric vehicle (EV), despite many prototypes in the early 1800s, was first made by Philadelphians Pedro Salom and Henry G. Morris and patented in 1894, being the first commercially viable electric vehicle called the Electrobat. 2 Despite substantial progress being made since the turn of the century, EVs have been around since the 1800s, but this advancement is no longer being driven by curiosity but by the climate change crisis we are facing. Cars are a major polluter of the atmosphere, accounting for 60.7% of total CO 2 emissions from road transport in Europe, 3 the only mode of transport producing zero CO 2 is either a bicycle or travelling by foot which are obviously quite slow, and so the development of EVs has seemed to be the only solution. In spite of the lack of fossil fuels to power the vehicle, is the environmental campaign a façade? Are they really as green as they seem? The typical ICE in an automobile involves a minimum of four pistons connected to the crank shaft. Each piston has two valves, controlling the intake and outtake of gas, and a spark plug to ignite the fuel. Car engines go through a four-stroke cycle of (a) intake – the piston descends sucking in an air-fuel mixture with the intake valve open; (b) compression – the piston ascends, compressing the mixture with both valves closed; (c) power – the spark plug ignites the compressed mixture, forcing the piston downwards and transfers this energy into the crank shaft; and (d) exhaust – the outlet valve opens, and the piston ascends causing the burnt gas to leave the chamber. It is necessary for the engine to have a minimum of 4 pistons so that at least one piston is performing a power stroke at any time; it is this in combination with the weighted crank shaft that keeps the wheels turning and the car running smoothly. 4 Pistons can also have various configuration for added efficiency and power (e.g., V6, V8, V10 etc.). Despite the first marketable EV being manufactured in 1894, the ‘ engine ’ used in many EVs today is the AC or induction motor made in 1888 by Nikola Tesla consisting of two parts, the rotor and the stator. 5 The rotor is a series of conducting bars which fits into the stator: an outer frame with electrical windings of insulated copper wire. A three-phase alternating current is fed through the electrical windings creating a four-pole rotating magnetic field (RMF), generating an electromotive force (EMF) and an induced current on the conducting bars. As the induced current interacts with the RMF a force is exerted on the conducting bars spinning the rotor and turning the crank shaft to spin the wheels. 6
1 Wilson 2018. 2 Ibid. 3 European Parliament 2019. 4 How a Car Engine Works 2021; Autotechlabs, How a car engine works . 5 National Inventors Hall of Fame 2021. 6 Donut Media 2018.
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