Take the plug-in electric Nissan Leaf which came to Boston a week ago in the final stage of a 24 city nationwide tour.

The elegant little car has a range of 100 miles on a full charge and only takes eight hours to fill up from a 240-volt outlet (that's what we use for washers and driers).

I know, only eight hours! That's too long in a world used to spending five minutes filling up the gas tank. But think about an electric plug-in as a vehicle which you will be constantly topping up.

When you get home at night, you plug it in. When you go to work, you plug it in. When you go to the mall, you plug it in. When you stop on the highway, you plug it in. Wherever you go, you plug it in.

No question, the 100-mile range is not going to work for everyone. It causes "range anxiety," which we all experience when the reserve gas light goes on and we don't know where the nearest gas station is. With an all-electric car, that condition is compounded by the amount of time it will take to fill the car up.

The Next Big Step
But following on the heels of Toyota's Prius, the Leaf is the next big step as we move toward an all-electric fleet. Future developments that are not many years out include batteries with a greater range and 480-volt outlets.

Battery technology is progressing, with the power-to-weight ratio giving us stronger, lighter batteries all the time. At the same time, there is serious consideration being given to creating a network of 480-volt charging stations. Such a move will require safety guidelines, permitting and licensing as well as the addition of cables capable of carrying the load.

But using such a station reduces the Leaf's charge time to less than half an hour. Now we're talking. To be sure, it seems to me that the range has to get up to about 250 miles and the full charging time to about 10 minutes for the plug-ins to stake a full position on the field. And it would also require a wide and dependable network of 480-volt charging stations.

How far out is this?
Consider that all transportation was horse driven just over 100 years ago. Imagine what life was like in cities like Boston, or New York or Providence. We may romanticize the sound of horse hooves on the streets, but I doubt if you would want to romanticize the all-pervasive smell of horse urine and dung, especially in the summer.

And yet in the space of three generations, the horse was gone.

Or take the electric light. How long did that technology take to become the standard, replacing smelly, labor intensive and far more dangerous candles and oil lamps?

I'll bet you that folks in 2050 could well be looking back at us in 2010 and wondering what it was like to live in a world with those noisy and toxic gas-driven cars.

On my desk I have a small model of the Wright Flyer which made a 12 second, 121 feet flight on Dec. 17, 1903. Next to it is a model of the Apollo II Lunar Module "Eagle," which landed on the moon with Neil Armstrong and Buzz Aldrin aboard on July 20, 1969.

Maybe the future is always closer than you think while the past is further away than you want to believe.