"I don't have an e-mail address. As much as I admire the Internet I suffer literally agoraphobia, which in it's original sense means a fear of the marketplace. I do not want to receive three hundred e-mail messages per week from strangers…"
- William Gibson

So was John Jacob Astor the first person to write about this idea? The earliest reference I can find to it is something that was called dynamic brakes used on electric trolley cars in the early 20th century:

The driver’s control handle had a position that cut power to the traction motors and supplied a small, finely controlled excitation current to the motors’ field windings. This turned the motor into a generator that was driven by the motion of the car. Increasing the magnetic field current increased the generating load, which slowed the car, and the current being generated was routed to a set of huge resistors on top of the car. These resistors converted the current to heat, which was dissipated through cooling fins. By the 1920s, techniques had been developed for returning that current to the power grid, making it available to all the other cars in the system and so reducing the load on the streetcar system’s main generator by as much as 20 percent. Regenerative braking systems like this are still being used in cities around the world.
(From Regenerative Braking Charges Ahead)