Someone showed me something online about wireless electricity (sorry to be so vague). The basic logic was that a magnetic field could be tuned to some frequency where it would only discharge to a device set to receive the power at that frequency. Is this possible? What would prevent it from discharging/grounding to something other than the intended receiver? What kind of wave would the transmission be? A microwave? An ion chain?

It is quite possible although usually looked at the other way. The transmitter transmits and the receiver is tuned to the transmitter. Examples are radio and television systems. In these systems the transmitter sends out EM waves at a particular frequency and only those receivers which are in range and have their input circuits tuned to that particular frequency will receive transmitted energy. Quite recently devices been made to pick up radiation at 50 or 60 Hz which is used to (say) charge a mobile phone in the home. This is usually described as magnetic induction see http://en.wikipedia.org/wiki/Battery_charger and scroll down to "inductive".

Sounds like something Tesla would have done. Try googleing 'Nikola Tesla'.

as far as I can remember he was working on a transmission tower which could transmit mains electricity to homes in the New York area.

There's an article about it here...

 

My link

Edited January 1, 201115 yr by tomgwyther

This is exactly what Nikola Tesla was doing, and he did it once, sadly he got so worried about people stealing his work that he started writing in a code that nobody has been able to crack yet, it would not be "Wireless Electricity" as you say, but it would convert other forms of Matter Into electricity, you have to remember, you cannot create nor destroy matter. only change it.. electricity takes the form of plasma sometimes (possibly all of the time, i have not looked into it this much) anyway, look at it like i have, just do some research on tesla coils and what the ORIGINAL was meant to do.

Apparently it is not only possible, it already exists and is avaliable on the consumer market. http://www.thinkgeek.com/stuff/41/wec.shtml although EM radition and an electrical current aren't exactly the same thing so you could argue that the wireless stage isn't strictly electricity.