The United States with its largeness and rugged terrain makes railroad electrification a difficult proposition. High capital costs maintenance costs also make it difficult too. To get around these problem electricity could be transmitted wirelessly. Tesla Developed technology to do just that but unfortunately it was never fully developed. Wireless transmission if efficient enough could solve all of those barriers to entry. The problem with current technology is that it has larger transmission loss. The Removal of catenary friction would also allow higher speed passenger trains. I find it weird that the Morgans who owned a large number of Railroads would kill funding for it.
I wouldn’t say it wouldn’t work, I don’t know enough about it one way or another, and I’m certainly no electrical engineer.
But I can just hear the screams, and I do mean SCREAMS from the NIMBYS if they try to erect one of those things.
PS: I love Tesla coils! Always wanted one.
Well, I’m an EE and I haven’t seen anything in the above links/discussion that really addresses energy transmission ‘efficiency’.
Tesla setups look pretty omni-directional to me. Also, way too much ‘power’ in for an (as yet) unquantifiable output at some remote location. Where the does the rest of the energy go? Hopefully not as a surge somewhere in nearby power transmission lines. I don’t want that power bill. As a side note, (except indirectly by geothermal means) we’ve haven’t been able to harvest useful power from the worlds largest power source - the molten iron core of the planet.
AFAIK a Testa coil produces a lot of electromagnetic interference across the spectrum. Not very nice to impact existing electronic devices and communication services.
A theoretical alternative (maglev aside) might be to transmit energy along the RR ROW only (riiiight) to a ‘small’, moving locomotive mounted receiver. Hmmm. Think microwave to light wavelengths. Besides the power conversion and moving target tracking challenges, the crew would have to be protected from that level of energy density (in kind of a reverse microwave oven - Faraday cage). BTW the U.S. military has been trying to do much the same thing with various high energy laser systems since the 1970s without much success. If they could propel a small missile with microwaves they might be interested, but when the missile disappears from the line of sight … thud.
O.K. now, where’s young erikem with his detailed calculations …
One problem is that the electricity can cause damage, in fact severe damage, to animals including human beings. We don’t feel high frequency electric waves but that doesn’t mean they cannot harm us.
After seeing the opposition to an extra-high voltage (765KVA) transmission line that was built near here some years back, I can’t begin to imagine what hassles and roadblocks getting such a system installed would have to overcome.
With wireless transmission all that is needed is a sending station. It doesn’t need towers to carry electric wires. So it might be quite easy to get the permission needed.
However, actually transmitting sufficient electric power through the air to power a train is easer said than done.
Broadcast radio stations send out multi-megawatts sometimes, but it goes in all directions, so by the time is has gone very far, there is barely enough to drive a small speaker in a non-power/non-amplified radio (think, Crystal Radio).
Confine it to a beam that does not spread out and you will cook any bird or other ‘animal’ that wanders into the path (Think microwave oven! Or why there is a switch on the landing gear of planes that shut off the nose radar when the weight of the plane is on the wheels. Don’t wanna cook the guy directing the pilot where to park if the pilot forgets to turn off the radar when he has landed!)
I don’t think wireless transmission of electrical power is a good idea!
When I was a kid I used to make simple radios. One of them was designed to tune in two stations. You tuned in the strongest station in your area; that station simply powered the radio to recieve the station hou wanted to hear.
Young??? I’m about the same age as Paul D North, Overmod and maybe a bit younger than Greyhounds… [;)]
There are a couple of different ways to transmit power sans wires. One is to use coupled high-Q resonators to make up for lack of coupling, but power transfer peters out when separation exceeds a few times the size of the largest resonator (near field). Keep in mind that the presence of large amounts of metal will do bad things for coupling. The other is use antennas to transmit power, good coupling can be maintained with dipole antennas up to about a quarter wavelength, much farther will require directional antennas and start looking like what MikeF90 was talking about. To get adequate power to the train, the power density of the beam would be approaching a MW/m^2, which would do a good job of cooking anything that got into the beam path - I’d rather deal with nuclear powered locomotives.
- Erik
Thanks to the EE’s who can point out the folly of such a system. I would think that induction currents would be a real issue too.
If you had multiple beam paths, you might not want to let the beams cross.[(-D]
That’d make cooking lunch at places like Deshler and Fostoria really easy… [dinner]
Just be sure your lunch is the only thing you cook.
You know, I think the nexr power source for locomotives could be something none us us could imagine, anymore than Stevenson could imagine an electric locomotive replacing steam.
Maybe a super-sized super-efficient solar cell mounted on the roof of the locomotive sending power to the traction motors? Could happen. I probably won’t live to see it, but who knows?
Well… lets see… the sun delivers about 1340 Watts of energy per square meter at the top of the atmosphere.
About 9 % is reflected and about 22% is absorbed by the atmosphere so only about 69% reaches the surface of the earth so you have available about 925 Watts per square meter to capture and turn into electricity.
Assume a 100% efficient conversion by some new fangled solar cell, (and unlike athletes that often claim to give 110%, solar cells cannot give more than 100%!).
So if your engine is covered in solar cells and the engine is, say… 20 meters long and 3 meters wide, then you have 60 Square Meters of solar cell available to make electricity.
That gives you 55,500 Watts of power to run your train when the sun is shining BRIGHTLY.
Uh… that is only about 75 Horsepower at NOON on a CLOUDLESS day.
I suppose that if you limit train travel to daylight hours, you might be able to haul a few people, SLOWLY to their destination. Assuming no tunnels, trees or clouds.
Presently solar cells are theoretically 33.7% efficient, so today you would only have about 26 Horsepower… at noon…
If we’re allowing ourselves to dream that trains could be powered using 100 year-old, wishful thinking technolgy from a near-mad genious, why don’t we just get some app for our I-phone that does the same thing?
I’m absolutely positive that somebody is thinking of such an app right now![I]
Tesla did give us AC - if Edison had his way, we’d be using DC in our houses…
The only way solar could power trains would be as a component of the supply for a catenary system.
Ummm, no. Thomson-Houston and Westinghouse were doing AC lighting systems before Tesla’s corroboration with Westinghouse. What Tesla did give us was polyphase AC and induction motors (though it took WEMCO’s B.G. Lamme to get the design right.
Or charging battery powered locomotives. Solar power and wind power both need some sort of economical energy storage system before they can realistically provide a significant portion of the electric power production.
- Erik
Can’t always believe what a science-channel show on a specific individual tells you, I guess, which is understandable. Still, he had a piece of the action vs Edison’s DC.
One method I recall seeing in the past for storage was a kinetic system - water was pumped up into a reservoir (lake sized) during excess power production, then released through turbines during high demand periods. Might be kinda hard to find suitable reservoir locations, though, among other issues…
The big ‘dome’ setups, like the one for Wardenclyffe, were highly directional. The dome is not the antenna – there were (going to be) many small directional ‘emitters’ like the seeds in a dandelion ‘puff’. A given emitter would not be brought ‘live’ until it had confirmed (via radio) that it was pointed at something actively receiving.
Of course, this was well in advance of Yagis, or digital signalling of the required precision, so how it would have worked in practice – who can say.
I notice that the EEs are ignoring the ‘scalar wave’ part of the Tesla solution, which is supposed to be different from the old E x B electromagnetic radiation we former Class 1s knew and loved. There is also the ‘telluric current’ return path – how that was supposed to produce high amperage RF current instead of just proportional RF slosh in and out of ground capacitance, I don’t know, and how it was supposed to power aircraft and rubber-tired vehicles for any length of time could have been interesting in its own right.
The short answer to the ‘failure’ of broadcast power was wireless – the use of which as a practical medium of communication would be short (pun intended!) And while we’re at it, telegraph and telephone wiring will neatly collapse the e-field and produce… well, you know. Same for electrical power wiring. Or fence wiring. Etc. (Not difficult, is it, to figure out why Mr. Morgan chose not to finance this approach – even before you take up the issue of metering the current draw rather than just the channel and direction…
“Surge”