Electric cars are the real world example of loose coupling. Once your car is electric the source of the electricity can change (from Coal -> Gas -> Solar) and you don't have to change your car even slightly.
So it doesn't matter about any of the arguments about whether an electric car is more efficient or not when the electricity comes from coal.
What matters is that having electric cars enables us to move to a future of solar and wind and not notice the difference.
Plus having electric cars that don't pollute in cities where there are lots of people and generating the electricity with coal fired powerstations outside of cities where there are less people has immediate benefits.
So it doesn't matter about any of the arguments about whether an electric car is more efficient or not when the electricity comes from coal.
What matters is that having electric cars enables us to move to a future of solar and wind and not notice the difference.
Plus having electric cars that don't pollute in cities where there are lots of people and generating the electricity with coal fired powerstations outside of cities where there are less people has immediate benefits.