Sebring-Vanguard CitiCarEnlarge Photo
By the time highway-capable EVs arrived in the mid-1980s, it might take nearly 30 seconds to achieve the necessary speed for freeway travel. That didn't do much to improve the public image of electric cars.
Christensen proposed that 0-to-60-mph acceleration time below 10 seconds is needed to make an electric vehicle feel safe merging onto a highway for average drivers. With the advent of modern motors and controllers, many electric cars now on sale meet or exceed that metric.
So within a few short years, most electric cars will offer adequate acceleration, and some of them [cough, Tesla], offer drivers a thrilling experience when the accelerator pedal is pushed into the carpet.
EVs to take on the mainstream marketplace
So with adequate top speed achieved, and suitable acceleration all but here, range seems to be the main metric that prevents electric cars today from taking on the fossil-fuel burners.
Most electric-car enthusiasts know this, even as they try to educate buyers on why a 70-to-80-mile range is probably enough for most people.
But while the oft-cited data that four-fifths of North American cars travel fewer than 40 miles a day is repeated ad infinitum, buyers aren't necessarily buying it. And that's even before the range-depleting effects of cold weather, climate control in the cabin, and long-term battery capacity degradation are factored in.
If Christensen is to be believed, the range of the typical electric car will need to increase by 50 percent or more over today's levels. According to the historical trajectory of improvement, that will take until 2030.
Watch out for 2017
Or will it?
Nissan has said it will likely offer a range of battery sizes on the next generation of its Leaf compact hatchback, perhaps going as high as 150 miles. Those seem likely to be shown in 2016, perhaps even earlier, and arrive as 2017 or 2018 models.
2012 Tesla Model S beta vehicle, Fremont, CA, October 2011Enlarge Photo
The Tesla Model III, the company's 200-mile mainstream sedan model, is due out in 2017 with a price target of $35,000 before incentives.
Either of those cars would tick all the boxes on Christensen's list--at a price close to being competitive with the average vehicle sold today. Still, a single car from just one or two manufacturers might not allow electric cars to break into the mainstream.
Consumers will want to see a range of cars from a range of manufacturers before they give cars with plugs the warm embrace.
GM makes three?
But if the rumors of General Motors offering an electric car with 200 miles of range prove accurate for 2017 as well, there might be a major jump in the historical increase of electric-car range--and the graph will then need some serious updating.
And the combined total of GM, Nissan, and Tesla should boost public awareness that electric cars can travel far more than 100 miles for prices well under $70,000.
With adequate acceleration and highway speeds dealt with, Christensen's book would have you believe that only range is holding us back from mass acceptance of electric cars.
Slow but steady improvements in the cost-performance of lithium-ion batteries, and the economies of scale, seem likely to take care of that challenge well within the next decade.
And advocates should be reassured by seeing the improvements plug-in electric cars have already made, over just the last 40 years, as we anticipate a future of cleaner driving.