Watts is watts?

[BrianG]

In your "over land" example, I don't quite agree. Resistance in wire produces a voltage drop with a certain amount of current. Increases in current will increase the voltage drop across the wire and decrease the available voltage at the end of the wire. So, to help minimize this, they use very high voltage at relatively low currents and then use transformers to step down the voltage and step up the current nearer the load. Transformers can sorta be considered "power" transfer devices - the output power will equal the input power (minus some losses). So, if the load (at the xformer output) is pulling 10A @ 120v, that's 1200W. If the primary of the transformer is at 1200v, that's only 1A (plus a little extra for losses).

That said, we don't use such high voltage or A/C transformers in R/C, nor do we transfer power over such long distances. The only thing we really gain with using HV setups is the reduced voltage drop on the wiring/connectors due to the heavy current, don't need such beefy connectors and wiring, and maybe some benefit for the ESC as fewer FETs are needed (becauses it's the current that determines how many parallel FETs are needed). But, this assumes you have a suitably high turn motor for that HV...