They did the whole math in "Sustainable energy without the hot air", and over all, even burning coal and using an electric car is better than burning petrol in a comparitively small engine.
Funny enough, a similar analysis applies for heating: burning natural gas to make electricity to drive a modern heat pump is more efficient than burning the gas directly for heat at the premises.
From a physical point of view, that's possible because you only need low grade heat for your home, but burning gas produces high grade heat.
Charging your battery might be less efficient.
They did the whole math in "Sustainable energy without the hot air", and over all, even burning coal and using an electric car is better than burning petrol in a comparitively small engine.
Funny enough, a similar analysis applies for heating: burning natural gas to make electricity to drive a modern heat pump is more efficient than burning the gas directly for heat at the premises.
From a physical point of view, that's possible because you only need low grade heat for your home, but burning gas produces high grade heat.