Consider the following information about an electric car. Let us assume that the car consumes the equivalent energy of 0.5-1 litre of gasoline to drive 15 km. 1 Wh = 3.6 kJ → Energy to lift 100 kg 3.7 meters 1 cal = 4.2 J → Energy to raise the temperature of 1 g water with 1 degree 1 MJ = 0.28 kWh → Energy to accelerate a car of 1000 kg to 161 km/h (no air resistance) 36 MJ = 10 kWh → Energy content of 1 liter gasoline What is the estimated energy required to drive this light electric car for 150 km?
Answers
Answer:
The CO2 content of any given source fuel is well understood. Coal is 23.8 grams of carbon per mega-joule and Oil is 19.9 grams of carbon per mega-joule.
Applying those carbon content levels to the vehicle efficiencies.
For 1 km of driving,
Carbon footprint of a small petrol car = 3.45 MJ/km x 19.9 g/MJ = 68.66 g/km
Carbon footprint of a small electric car = 1.35 MJ/km x 23.8 g/MJ = 32.13 g/km
Carbon footprint of a diesel SUV = 5.88 MJ/km x 19.9 g/MJ = 117.01 g/km
Carbon footprint of an electric SUV = 3.12 MJ/km x 23.8 g/MJ = 74.25 g/km
Carbon footprint of a petrol scooter = 1.03 MJ/km x 19.9 g/MJ = 20.47 g/km
Carbon footprint of an electric scooter = 0.44 MJ/km x 23.8 g/MJ = 10.47 g/km
This assuming that all the electricity comes from coal. This is not true, quite a bit comes from other sources with a lighter or zero carbon footprint. And even if you take the process of car manufacture but subtract the electricity used in refining oil and making petrol cars, electric vehicles will win out.
Explanation: