Reuters: Top automakers finally have electric cars ready to purr into dealer showrooms. Now the question is whether the charging infrastructure and electricity supply are up to the task. Industry watchers question if power grids can cope with the influx of electric vehicles, even though EVs are likely to remain, at least at first, a fraction of the new car market. But as CO2 emissions rules tighten, carmakers need to take action. “We need a radical solution,” Renault and Nissan Chief …