by Bill Roberson
After all the hoopla around Elon Musk’s Hyperloop plans last week and his general enthusiasm for all things battery and solar powered, I got to thinking more about some blue-sky ideas about other aspects of travel and transportation that could be changed with these burgeoning sources of electricity and electric propulsion.
Here’s what I came up with.
Trains, like cars, are essentially an ancient but proven technology. Steam-powered locomotives date from about 1814 and horse-drawn rail systems go back quite a ways before that. Despite a popular (and patently false) tale that modern rail gauges are based on the width of a Roman chariot, rail systems have modernized within their paradigm as the years have gone by. Not many people know this, but a modern train in the United States is closer in operating principle to a toy electric train set than the glorious steam engines of old. That’s right: modern trains run on electricity.
Rather than pulling power from electrical wires overhead like some hellaciously fast Euro and Japanese trains do, modern diesel-powered locomotives use their engines to generate electricity which then powers electric motors to drive the locomotive’s wheels. So why not supplement or replace the liquid fueled- electricity source at times with some solar and battery power?
Elon Musk said he wanted to put solar panels on the Hyperloop to power it, but covering the whole thing with photovoltaic panels might generate too much power so that was a work/concept in progress. That’s a lot of power. So how much solar power is pelting the rooftops of a regular old freight train hauling a mile’s worth or boxcars? With a standard boxcar being 60 feet long by about 10 feet wide, that’s a lot of solar space. Using thin-film, lightweight solar panels, it would not be a stretch to hook all that power up and route it back to the locomotives, which could then either run in the flat on solar power alone, saving huge amounts of fuel, or in a hybrid mode for ascending grades. If the locomotives and rolling stock all had regeneration and storage ability descending a grade, that power could be largely reclaimed.
A lightly modified boxcar and locomotive design could incorporate the panels into the roof along with a small (500-pound, 20KWh?) battery into each car (and any kind of train car could carry a battery) to save the regen juice and use it when needed or at night. Steam engines carried tons of coal in a coal tender behind the locomotive, why not a dedicated battery car holding a few megawatts of juice?
Such a redesign of a train’s running gear would require zero infrastructure changes (same tracks and controls) and little technological intervention since trains are run by computers for the most part already. Trains are already wired together for data transmission between pusher and puller locomotives and braking controls so the conversion there is easy. Indeed, any rail car could be self-propelling to some degree, changing a train’s motivation from simply pulling the rail stock as has been done for centuries to a computer-controlled centipede model where every car is a little engine that can. Self-powered rail cars could also be moved around a rail yard without the assistance of a yard locomotive.
Cost, as always, is a factor, but if a new boxcar costs $80,000 (a figure that seems to be accurate) and a battery plus solar array is $5,000 (at most), amortized over time and with fuel savings, it would pay for itself fairly quickly. After that, it’s just fuel savings gravy. The panels are up out of the way on the roof, there are no moving parts and the science is long done. Making the system modular would allow for easy upgrades of panels, batteries and motors.
Travel and trade by ship is as old as travel itself and the current state of the art for moving a lot of goods from port to port is container ships, some which are truly modern marvels in terms of size and power. But like trains, there’s a lot of solar power raining down on them all day so why not put all the square footage to use? Shipping containers are completely modular and typically serve for many years without damage, so mounting a thin, permanent solar array to the top of it would not require a drastic redesign, if any.
Crane operators stack the containers like LEGO bricks so a robust self-connecting power system built Read more »