Electric vehicles
* Are electric cars more efficient? *
Running a gasoline car involves:
- Burning gas in the internal combustion engine and converting thermal energy to mechanical energy. That’s it.
Charging an electric car’s battery from the grid and driving the car involves:
- Burning gas at the power station and converting thermal energy of gas to mechanical energy of the gas turbine. This is only moderately more efficient in a power station than gasoline cars.
- Then, losses begin:
- Converting the mechanical energy of the turbine into electrical energy in the generator involves generator losses
- Converting medium voltage from the generator into high transmission voltage involves transformer losses
- Transmitting the power along the high voltage lines involves transmission losses
- Stepping down the voltage in several substations involves transformer losses again
- In a home charging station, converting 220v power into DC for car charging again involves conversion losses
- A chemical process in the battery being charged heats the battery, involving charging losses
- Running the car’s electrical motors from the battery requires inverter losses to generate electricity for traction motors and motor losses.
Take a look at what happens when a driver needs heat in the cab:
- Heating a gasoline car in winter involves redirecting waste heat (hot antifreeze) from the engine into the cab heater, thus not requiring additional fuel.
- Heating an electric car requires a resistance heater or a heat pump, needing to eventually consume more energy from the grid - with all the above conversion losses included.
Which process (gasoline car vs. electric) is more efficient at converting fuel, burnt directly in the car engine or at distant power stations, into usable energy to propel a car traveling on a highway? The gas engines win outright.
The situation would be different if we had a clean, weather-independent, and inexpensive electrical power source. But, alas, we do not have that yet.
(Source: "Europe Abandons All-Electric Car Mandate")
