As you say. Many people who have their own solar panels and rarely venture far basically get their 'energy' for free. But with the fast charging network the companies are trying to cash in at the moment, as there's still not a sensible competition. Some brands (including German ones) will actually give you electricity for free for a certain amount of time, which makes the deal that much sweeter financially speaking.
Now imagining you on a low fuel consumption run somehow feels unnatural