Decarbonizing Aviation Ground Operations 2025

Cross-technology comparison of buses based on climate impact, operating costs, investments and airport operationsFIGURE 3 Climate impact The environmental story of airport buses begins with diesel, a technology that has reliably powered fleets for decades but now stands as the benchmark for emissions and energy consumption. Diesel buses, while robust and familiar, are the primary ground transport contributor to greenhouse gas emissions and local air pollution at airports. Retrofitting these vehicles with electric powertrains offers a meaningful step forward – reducing emissions and energy use. The real transformation comes with battery electric and hydrogen fuel cell buses. Both technologies promise zero emissions at the point of use, fundamentally changing the airport’s environmental footprint. Battery electric buses can reduce greenhouse gases and local pollutants dramatically, especially when powered by renewable electricity. Hydrogen buses also offer clean operation, emitting only water vapour, but their broader climate benefit depends on how the hydrogen is produced. If sourced from renewables, the impact is profound; if not, some of the environmental gains are offset, highlighting that the climate impact is not just about the bus fleet itself, but about the energy ecosystem that supports it. Upfront costs and investment When looking at their upfront costs, diesel buses remain the most accessible and affordable option for many operators. Their widespread availability and mature supply chains keep purchase prices low. Retrofitting diesel buses offers a pragmatic alternative for airports with newer fleets, enabling emissions reduction at a lower cost than purchasing new vehicles. While often presented as costing around half the price of a new bus, actual expenses can vary significantly depending on the age and condition of the base vehicle. Older units typically require extensive refurbishment – replacing major components and sometimes refitting interiors. Additional logistical expenses, such as transporting buses to specialized refurbishment centres, add further to the investment. Moreover, the retrofit market, though expanding, remains less standardized than that for new electric buses.Note: *OEMs: Original equipment manufacturers Category Criterion Diesel Retrofit Electric Hydrogen Climate impact CO 2 emissions during operation High Zero Zero Zero Energy consumption High Medium-High Medium-High Medium Fuel/Energy source Diesel Electricity Electricity Gaseous hydrogen Upfront cost and investment Airport bus market availability Global, >15 OEMs*Growing, ~10 OEMs and retrofit specialists>10 OEMs, expanding rapidly~5 OEMs, limited models, pilot projects Infrastructure requirements Diesel stations Charging stations Charging stationsGaseous hydrogen station Technology maturity High Medium Medium Low Ongoing operating costs Maintenance requirements High Medium Low Medium Expected service lifetime 15-20 years10-15 years (battery replacement required)12-18 years (battery replacement required)12-18 years Ongoing operating costs Airport planning implications Minimum Grid upgrade Grid upgrade Hydrogen ecosystem Operational range Long Medium Medium Long Refuelling/Charging time Short (minutes)Short/Medium Fast charging <25 min Overnight charging 3-4 hoursShort/Medium Fast charging <25 min Overnight charging 3-4 hoursShort (~10 min) Driver/User acceptance Medium Medium High (training needed) High (training needed) Decarbonizing Aviation Ground Operations: Alternative Bus Technologies 12