747-400 has 4 engine driven generators of approx 90KVA = 360KVA
A380 has 4 engine driven generators of approx 150KVA = 600KVA
767 has 2 engine driven generators of approx 90KVA = 180KVA
Each aircraft can have 1 generator unserviceable under MEL so design elec output is
vaguely based upon;
747-400, 3 x 90 = 270KVA
A380, 3 x 150 = 450KVA
767, 1 x 90 = 90KVA
All aircraft have a "load shedding" or priority system for elec usage.
I.E you can have lots and lots of power hungry seats, IFE, galleys, showers, internet, hairdryers, elec window shades etc, etc, etc, etc.
However, critical systems will always take priority over this crap when limited elec supply is available (I.E MEL of an generator) or during critical
flight phases. Examples are config changes such as flaps moving or gear in transit when elec hydraulic pumps come on, fuel jettison when lots of
heavy duty fuel pumps start up or engine failure when a generator is lost.
As you can imagine, these scenarios are basically take-off and landing when no-one is moving their seat, having a shower etc. All these nice to
have things are used during cruise and are a random demand not all used at the same time. So there is a "relative" abundance of power available
for your new design seat. Don't forget that all 'elec' seats must have designed in, manual overides to return the seat to the TTOL (Taxi,TakeOff,Landing)
position in case of elec supply not available.
Good Luck
