How much electrical power does one generator produce on a large turbofan?
This is one of the four Variable Frequency Generator (VFG) of the Airbus A380. It's apparent power is 150 kVA.


Rotor, source: Safran

The total power available from the engines is 600 kVA.

Seen from the other side:


Stator, source: Thales

The A380 is a one of these "more electrical" planes, where hydraulics tends to be replaced by electric devices, and the electric circuits have been optimized by electronics and variable frequency. There are secondary sources for electricity: APU (auxiliary power unit) and RAT (ram air turbine). Overall view from the book Civil Avionics Systems (Moir, ‎Seabridge, ‎Jukes):


Source: Civil Avionics Systems

In case of total failure, the ultimate RAT backup is totally electric-based contrary to conventional aircraft where some hydraulics is also provided by the RAT to move the control surfaces.