What is 'load' in percentage?
There is an upper limit to the amount of power each generator can supply. That upper limit is 90 kVA.

At any given time, the amount of power needed to operate the aircraft systems will vary depending on which systems are active. For example, pumping fuel between tanks presumably uses electrical power and increases the load on the generators.

The amount being used can be expressed as a percentage which gives you an idea of how much reserve capacity the generator has available to power new loads.

If both generators are operating with a load of 26% and one fails, I imagine the remaining generator would take over the job of providing all power† and would then be operating with a load of 52%.




From Airbus STL 945.7136/97 1998 - A320 Flight Deck and Systems Briefing for Pilots

† Apparently, on the A320, a failed generator is replaced by the 90 kVA Auxilliary Power Unit (APU) if that is available. Only if the APU is not available is the load transferred to the remaining main generator. In the latter case there is automatic galley load shedding - I think that means the PAX get cold meals :-(