Yes, all else being equal, cost is the only thing that matters. But often all else is not entirely equal, and then an analysis like this may be helpful. For i

Yes, all else being equal, cost is the only thing that matters. But often all else is not entirely equal, and then an analysis like this may be helpful. For instance, if you look at the transportation sector, you don't actually need to supplant all the energy there, only the actually useful part. And batteries + an electric motor is in fact much more efficient than gasoline + an internal combustion engine.