The invention relates to an aircraft
ground support unit (1) (GSU) for supplying a specific service according to a specific set of service parameters to an aircraft (2) on the ground and consuming a specific service energy for supplying the specific service as a whole in a given available service duration, the GSU comprising: a rechargeable
energy storage unit (3) (RESU) which, when fully charged, is configured for autonomously delivering the specific service energy required for supplying the specific service in the given available service duration, an energy sensor (4) configured for measuring an instantaneous
state of energy parameters of the RESU, a
control unit (5) configured for, • identifying the aircraft (2), preferably including an aircraft type and an airline, • identifying in the
database the specific set of service parameters of the specific service to the thus identified aircraft, • establishing a specific service energy budget estimate corresponding to the specific set of service parameters in various ways, • determining an instantaneous charge level of the RESU based on the instantaneous state of the energy variables, • comparing the specific service energy budget estimate with the instantaneous charge level of the RESU, and for • generating an output
signal representative of a capacity of the RESU to deliver the specific service energy budget estimate as a function of the instantaneous charge level of the RESU.