Total cost of ownership (TCO) analysis3 The TCO analysis presented in this paper evaluates the high-level economic implications of adopting different sustainable bus technologies in the airport environment, considering both capital expenditure (capex) and operational expenditure (opex) across the expected service life of the vehicles. Capex includes the upfront costs associated with vehicle procurement, installation of supporting infrastructure, and any necessary modifications to existing facilities, such as maintenance depots or fuelling stations. Opex covers the recurrent costs incurred during operation, including fuel or electricity supply, scheduled and unscheduled maintenance (including battery replacement), staff training, insurance, licensing and other ongoing operational expenses. To ensure a simple comparison between alternative bus technologies, this study has chosen the archetype of a European international hub airport. It has been assumed that a similar airport may operate a 50-airside bus fleet. Leveraging over 20 interviews with Airports of Tomorrow and aviation stakeholders conducted from March to August 2025 and quantitative research, some operational parameters (e.g. bus distance travelled) have been estimated and validated to ensure the analysis can be as representative as possible of potential real- world applications. The full methodology is set out in the appendix.3.1 Reference case study and scenarios considered Reference case parameters for the European international hub mid-sized airport TABLE 1 Operational parameter Value Comment Fleet size (number of buses) 50 - Number of drivers (per bus) 3 - Bus driver salary (€/driver) 36,580 - Operating hours (hours/day) 18 - Operational days 365 - Utilization rate (%/bus) 25 Share of operating time during which bus is carrying passengers Bus average speed (km/hour) 20 - Bus distance travel (km/day/bus) 90 Calculated as utilization rate × operating hours × average speed Bus annual distance travel (km/year) 32,850 - Investment date (year) 2030 Applicable for all technology options analysed Project lifetime (years) 15 Assumed lifespan for buses Weighted average cost of capital (%) 4.56 Based on average for three regulated airports15 Corporate borrowing rate (%) 4.10 Based on European Central Bank (2025) data16 Banking department amount considered (%)0 Full investment assumed to be made upfront Decarbonizing Aviation Ground Operations: Alternative Bus Technologies 14

Decarbonizing Aviation Ground Operations 2025