Ground Support Equipment (GSE) fleets must be made more sustainable to contribute to the achievement of emission stabilisation and reduction goals for a growing aviation sector. Electrification of GSE offers great opportunities to mitigate greenhouse gas emissions, thereby increasing sustainability. This research focuses on how to design an airport service infrastructure for sustainable refueling of aircraft using electric refuelers. Although important for the design of such infrastructure, current literature fails to investigate potential emission reduction as a result of implementing electric GSE in mixed fleets with conventionally fueled GSE. Therefore, this work presents the development of a capacity model that quantifies the performance of sustainable refueling service infrastructures, consisting of partially (or fully) electrified fleets and charging points, in terms of annual CO2e emissions. Using future flight schedules as input, this algorithm models the activity of electrified refueler fleets taking charging downtime and forecasted airport growth into account. Model outputs provide insights in future fleet size, fleet mix and charging infrastructure requirements on a tactical level to achieve carbon emission goals for refueler fleets on a strategic level. As capital investments have to be made to electrify refueler fleets, the effect on the Total Cost of Ownership for ground handlers is investigated as well. The entire model functions as an essential input for future airport design related to aircraft services.