ELECTRIC cars are clean, quiet and, it seems, the way of the future. Tesla, an American firm that has done much to help electric cars shed their museli-munching image, is struggling to meet demand for its mid-market Model 3 (it has announced plans to build electric lorries as well).
Volvo, a Swedish carmaker, has said that, from 2019, all its cars will be at least part-electric. Volkswagen has plans to offer battery options across all of its brands; General Motors has made similar noises. Some countries, including China, Britain and France, are mooting bans on internal-combustion vehicles, to take effect within a couple of decades.
Not all forms of transport are so easy to electrify. One of the hardest is aviation, where battery power runs up against weight. Fossil fuels contain roughly 100 times as much energy per kilo as a lithium-ion battery.