A lot of people who talk about the coming future of post-petroleum vehicles like to pooh-pooh the battery electric car, even though it’s the most successful type so far. They keep insisting that the real future will belong to hydrogen fuel cells or ethanol or something else exotic.
But consider the following vision for a future car:
It’s an affordable compact or midsize, nothing fancy. The base model comes with an electric motor for each front wheel, and 25 or 30 kilowatt-hours of batteries layered under the floor. This arrangement keeps the powertrain out of the way, so it can have a trunk at both ends, like a Tesla. Its range is at most a hundred miles, so it’s fine for commuting and shopping and local excursions, but very inconvenient for a road trip.
Most people accustomed to gasoline cars would find this a bit disappointing. But consider the upgrades you could buy for it. If you want sure-footedness in snow, or more performance, add a pair of rear motors. (They would be smaller than the front ones, unless you’re doing some aggressive hot-rodding.) If you want longer range, you could have a second battery pack in place of your front trunk. And… if you want to drive everywhere and refuel with gasoline, you could replace that front trunk or second battery with a small gasoline engine and a generator. It could be no bigger than a motorcycle engine, because it would only need to produce fifteen or twenty horsepower to keep your batteries from draining while cruising down a highway. Ideally it would be a turbine rather than a piston engine, as it would only run at one speed.
Or if gasoline goes out of fashion, you could use that space for a fuel cell and a hydrogen tank. Again, it would produce only a steady fifteen or twenty horsepower. Or there could eventually be other alternatives not well known today, such as liquid-fueled batteries which you refill with exotic ion solutions, or metal-air cells fueled with pellets of zinc or aluminum.
These would not have to be options you choose when buying the car, but could just as easily be aftermarket modifications. They simply bolt in! Anyone with a hoist could swap them in minutes. Even the trunk would just be a bolted-in tub. With a good design, these power options might be interchangeable easily enough that people could just rent such an add-on as needed, rather than buying it. It might be cheaper than, say, renting another car for a vacation trip.
Another option might be to install stuff from below. There have been plans to make a network of stations where a machine just unclips your empty battery and slots in a full one, from underneath. With forethought, this car could be made compatible with such a system.
The point is, once you have the basic platform of a battery-electric car, it can be cheaply adapted to run on any power source. You could run it with coal, or with thorium, if you’re crazy enough. Whatever becomes the most economical and abundant power storage medium of the future, your existing car can take it onboard. All you need is to make sure it has some unused room under the hood.
And the best part? Even if you don’t add anything, you still have a plug-in car that’s perfectly okay for most everyday uses. In fact, I suspect a lot of people might come to prefer the car with no add-on, because it’s lighter and quicker and more efficient that way, and it has two trunks.