Tag Archives: Efficiency

Electric Car – A farce

The electric car is one of the biggest objects of farce in today’s age. People keep on crying about how electric cars run on electricity and not by burning hydrocarbons and hence they are less polluting and “environment friendly” Ha. Ha. Looks like the people who say this have never believed in anything written outside text books and tabloids or understood a few simple concepts of physics.

Let’s take for example a regular petrol/diesel powered car. The efficiency of a stock normal compression petrol engine is around 30% and that of a diesel engine is 45%. That means 45% of the energy obtained from burning fuel is actually converted into mechanical energy to move a car and this includes mechanical loss and heat loss. For high performance cars, the figure may be up to 50%.

Now let’s take the “environment friendly” electric car. An electric car motor has an efficiency of around 90%!! Wow!! Isn’t that amazing?? And also so pollution free! Not quite so! Where does the electricity used to charge the car come from? From power plants. What do these power plants run from? In India, 87% power is produced by burning coal. The efficiency of a typical Indian power plant is around 23%(US=33%) which means a loss of 77%. Add to that transmission losses of around 15%(US=9%). Battery charging efficiency is at the best 70% which means a loss of 30%. This brings the total efficiency of an electric car down to 19% starting from the first fuel. And this is using coal, which is much much more polluting than petrol or diesel. I’m not even taking into account the fact that half the weight of an electric car is the batteries which is a waste of the mechanical energy. Also, each megawatt of power utilised more in the cities means 1 less hour of electricity per day in the villages. And the villages i’m talking about get only a few hours of electricity per day as it is.

Let’s look at the total efficiency figures of a diesel and electric car

Diesel—–Diesel Engine 55% loss——> Mechanical Energy = 45% Efficiency

Coal/Diesel—-Turbine power plant 77% loss—>Transmission 15% loss—>Battery charging 30% loss—->Electric Motor loss 10%—->Mechanical Energy = 19% efficiency

Modern diesel and petrol engines are almost pollution free and you also get performance and practicality. Would you want to go on a road trip and stop for a charge every 100km or so and even then crawl along at speeds not more than 80kmph. And for all this you shell out 4 times as more than you would for an Internal Combustion car and also have people laugh at you.

Unless more efficient and pollution free power generation is adopted, the electric car is clearly impractical and in fact more polluting than a normal car. The only difference is that a normal car pollutes the urban section and the electric car pollutes the suburbs and the rural. The blame of pollution is just passing from your conscience to the government.