http://www.overunity.com/7679/selfrunning-free-energy-devices-up-to-5-kw-from

Here in this demo you can see the 100KW device running, which is basically 3 Tesla coils hammering the High voltage onto special designed output coils and transforming the high Voltage HF AC down to 230 Volts AC at high amperage.
This is a 3 phase AC system.
As you can see in the input amp-meters on the left side the input current is almost zero and at the right side in the output tower case you see the amp meters putting out each about 60 to 70 amps at 230 Volts AC !

That is about 48 KiloWatts of output power from almost no input power ! WOW !
So we have a huge COP over here.