Already here

Same way your mobile device charges the battery on a charging pad or the way your electric toothbrush charges.

There is a bit more to it than that...

If you watch the video there is a significant difference in both the range and the amount of power being broadcast.  The devices described in the video aren't just charging a battery at extremely close range, the power is being sent throughout the house, to devices at some distance from the transmitter (at least across the room presumably) that are running in real time.  To me this at least suggests a successor to the keep-alives...

range and the amount of power being broadcast

I was speaking to the OP's question "I wonder how much they'll be able to miniaturize this technology". Miniature is already here.

According to the video it is exactly the same principle as is currently employed. Just on a much grander scale.

Tesla was working on this

Faraday Cages

Dear MRHers,

Believe Messer Faraday also tried his hand at this, within a chicken-wire cage/room. Pity it would affect all RF devices, and may pose issues entering/exiting the room...
(Hint: the human body makes a great earthing stake...)

There are also enough concerns about EMR effects on the human body from various localised transmission devices already (WiFi, cell phones, etc), that surrounding a body in a full-transmitting cage for multiple hours may prompt concern...

Happy Modelling,
Aim to Plug it In, and Turn it On,
Prof Klyzlr

Health risks ...

... 

This is the main "problem" ... we don't know enough about the long range risks.  It has been shown that above certain levels of exposure, significant fragmentation of large organic molecules (i.e., DNA) occurs ... so ...  the question becomes "At what level does the damage become undetectable?"  I suspect that similar to ionizing radiation, what the studies will find, is that any exposure above "background" levels, increases the risk.

Yes, it is a wonderful idea, however, a lot of folks died of radiation exposure while working with and studying radioactivity before they understood how dangerous it was.  After gaining a better understanding of the risks and how to protect ourselves from those risks, the technology may prove to be quite useful.

Qi Charging

My OralB toothbrush is surprisingly strong and the battery seems to last a long time even out of the wireless charging cradle. It must work the same as my cell phone charging pad - the Qi charger is what I use. A pad on the inside of an engine house with receiver in the tender could charge my dead rail engine. Now the pad was about Fourty Bucks and the phone case another $25 or $20 so I'm reluctant to reverse engineer them but the idea of never having to plug in the battery or remove it to charge is quite tempting. 

Neil Erickson

trying ...so hard...not to ....comment.....

According to Tesla there would be no radiation...

• 1891: Tesla demonstrates wireless energy transmission by means of electrostatic induction using a high-tension induction coil before the American Institute of Electrical Engineers at Columbia College. ^[65]
• 1893: Tesla demonstrates the wireless illumination of phosphorescent lamps of his design at the World's Columbian Exposition in Chicago. ^[66]
• 1893: Tesla publicly demonstrates wireless power and proposes the wireless transmission of signals before a meeting of the National Electric Light Association in St. Louis. ^{[26] [67] [68] [69]}
• 1894: Tesla lights incandescent lamps wirelessly at the 35 South Fifth Avenue laboratory in New York City by means of "electro-dynamic induction" or resonant inductive coupling. ^{[70] [71] [72]}
• 1896: Tesla demonstrates wireless transmission over a distance of about 48 kilometres (30 mi). ^[77]
• 1897: Tesla files his first patent application dealing specifically with wireless transmission.
• 1899: Tesla continues wireless power transmission research in Colorado Springs and writes, "the inferiority of the induction method would appear immense as compared with the disturbed charge of ground and air method." ^[78]
• 1902: Nikola Tesla vs. Reginald Fessenden – U.S. Patent Interference No. 21,701, System of Signaling (wireless); wireless power transmission, time and frequency domain spread spectrum telecommunications, electronic logic gates in general. ^[79]
• 1916: Tesla states, "In my [disturbed charge of ground and air] system, you should free yourself of the idea that there is [electromagnetic] radiation, that energy is radiated. It is not radiated; it is conserved." ^[81]

Anybody remember folks standing under transmission lines...

with florescent tubes that would light up as they held them above their head?

Here is a 12 minute video with a lot of tubes.

Den

wireless energy transmission?

Seems like the big problem would be directing the energy to a specific location along a well defined path. With wires we know where the energy is at all times while in the air it would be harder to confine it. Wires can bend and the energy flows with the bend while in the air it would need to be redirected at every turn or change of bearing. Seems like it would take lots of effort  to keep the air from being contaminated by various energy transmissions if they were not all confined to their own paths? and undirected energy would be wasting all that energy that flows to places other than the intended device?  ....DaveB 

the idea behind it...

the idea behind it is it works with both the air and the ground, so it's not like one circuit path through the air.  i read about it a long time ago, if i remember right it has to do with the charge of the earth and then using two poles (which is the air path) and the charge in one of the poles would create the path to the other pole, or something of that sort.

also...

Telsa was working on free electricity for everyone when building the Wardenclyffe Tower for trans-Atlantic communications funded by JP Morgan.  The project however was shut down once JP Morgan found out about his free electricity "side project".

http://en.wikipedia.org/wiki/Wardenclyffe_Tower

Yes, there are generally 2 of them...

which, of course, can lead to twice as many continuity, conductivity and connectivity issues you have to contend with...  Removing the control signals from the rails is only step one, albeit major.

I have no knowledge of the safety (or lack thereof) of such systems but for the sake of argument let's say they can become the hub of a house's power distribution system.  If such a system can be built to support miniature receivers no bigger than a TCS' KA-2 (assuming power levels can be kept low enough to make hobby electronics happy) and not blow up our can/open-frame motors, then when combined with RC the tether to an engine is gone.  You may want to wire your layout for FX (sound, etc.) but your copper budget would presumably get rerouted to other hobby purchases you're longing to make.

Add a simple power kill-switch to your in-engine controller and you no longer have to fear that removable bridge you added to the layout.  I'm sure someone will kludge up some kind of occupancy detector that can be activated when the bridge is out and it will scream at the engine "for God's sake stop!" and trigger the kill when necessary.

Yes, I did leave the door open and now I think I'll go outside to play...

POWER transmission

Yup, wireless power transmission is being done on a large scale:

http://www.navy.mil/submit/display.asp?story_id=80172

It just has to aimed down the track, I suppose!

Wireless lighting

While I was in the navy I saw wireless lighting in practice. We were being trained on the F14 Tomcat's radar system one night. The student technicians trained on the planes at night and the student air crews flew them during the day. One night a young government worker was carrying an armload of florescent tubes down the hanger bay. The instructor had a student turn the radar override off and hit the worker with the radar beam. I don't think the young man's boss believed he dropped those bulbs because they came on.

Regards, John

An appeaser is one who feeds a crocodile, hoping it will eat him last. <> Winston Churchill

Dead Rails

I did leave the door open. I have no wires to my rails. I model On30 with batteries so this has some real sex appeal. The idea of having some charging rails rubs me the wrong way as I try to become disconnected BUT wireless charging on the rails seems cool. Super caps are the next direction and each choice we make has downsides in terms of safety. Early adoption is what drives the market. 

Prof: you are one of the many I enjoy following as your experience and insight are often on the mark. Glad you have a sense of humor as well!

Neil

A cow shed radio

A friends father owned a dairy farm near the large Radio Australia station near Shepparton Victoria. When conditions were right you could here the radio inside the milking shed. Somehow the corrugated iron was picking up the signal and would vibrate enough to be able to clearly hear the programming. Interestingly you could not use a normal AM/FM radio in the area as the powerful RA signal would swamp anything else!