Do electric vehicles really use less energy? People seem to think yes. But the more I research about it, the more doubts I have.
Internal combustion engines have an efficiency of about 25%. Only 25% of the chemical energy of the fuel reaches the wheels. The rest is lost as heat, which is why internal combustion engines need a sophisticated cooling system.
Electric motors have an efficiency of about 90%.
When you charge the battery, it warms. When the battery discharges, it warms. So part of the energy that goes in and out of the battery is lost as heat. According to anecdotal information, this charge/discharge efficiency of the battery is around 80%.
Electric vehicles consume electricity. Where does this electricity come from? That’s a hard question. In most countries by far the largest electricity producer is fossil fuels. Fossil fuel power stations have an efficiency of 33%-40% for coal; it can reach 60% for natural gas.
Overall, it turns out that the electric vehicle has an efficiency of 24%-70%, depending on the source of the electricity. It will mostly be on the low end of the range, similar to an internal combustion vehicle.
Finally, there is the energy required to construct the battery, which is phenomenal. When you divide this by the lifetime mileage of the vehicle, electric vehicles seem to lose.