With an internal combustion engine you:
- Fill it with fuel
- Mix the fuel with air and set fire to it
- Use the resulting explosion to drive a block of metal called a 'piston' down a cylinder
- Via linkages, turn the downwards movement of the piston into circular movement of the wheels
In an electric vehicle the concept is broadly the same - fill it with fuel, discharge the fuel to a motor and use the spinning of the motor to drive the wheels.
However, because a lot of the fuel energy used in an
vehicle is wasted generating heat during the explosion, discharging the heat and transmitting the power through the linkages to the wheels, the overall efficiency of the engine isn't great.
In addition, a lot of harmful gases are discharged when the fuel is burned, such as carbon monoxide ('CO'), carbon dioxide ('CO2') and oxides of nitrogen ('NOx').
With electric cars and vans the power stored in the fuel (electricity in the batteries) is sent straight to the motors.
Because the motors are attached directly to the wheels there's far less energy lost transmitting power to move the vehicle.
Not only that, electric motors develop their maximum power the moment they begin to spin. As a result, EVs have proportionately faster acceleration than equivalent
However, all that electricity still has to get to the batteries in the first place and to do this many power stations burn fossil fuels with harmful emissions like those of petrol and diesel.
Electric cars and vans do, though, have a way of regenerating some of the battery energy 'lost' when moving. The braking systems in EVs are designed to recapture some of the energy applied in braking in order to recharge the batteries.