脱碳航空地面运营：替代巴士技术

随着全球航空业迈向2050年实现净零排放的目标，机场作为关键环节，正加快转型，尤其是在减少地面交通的排放方面。机场巴士作为航空地面操作的重要组成部分，其绿色转型已成为减少机场碳足迹的核心战略之一。报告详细分析了不同替代技术，特别是电动巴士、氢燃料电池巴士和改装电动巴士的全生命周期总拥有成本（TCO），为机场运营商提供了清晰的经济决策路径。根据该报告的数据，改装柴油巴士是当前成本最具竞争力的选择。通过将现有的柴油动力巴士改装为电动驱动系统，机场能够在不完全更换巴士车队的情况下，迅速减少排放。这一解决方案的资本支出（CapEx）较低，政府补贴（假设为50%）也进一步降低了前期投入。改装电动巴士的年运营开支（OpEx）约为495万欧元，单位每公里的TCO为3.20欧元，是所有选项中最具性价比的方案。相比之下，全电动巴士的初始投资较高，单车采购成本为55万欧元，并且需要大规模建设充电基础设施，导致资本支出达到930万欧元。但在运营方面，电动巴士的维护成本较低，且无需依赖传统的柴油能源，长期运行的运营成本也较为可控。综合来看，尽管电动巴士的TCO（每公里3.35欧元）略高于改装电动巴士，但考虑到政府的资金支持和长期的绿色发展目标，其经济效益和环保效益是明显的。氢燃料电池巴士虽然在运营灵活性上具有优势，尤其是在大型机场和高强度运行的场景中，能够实现快速加注和较长的续航里程。然而，其高昂的前期投资和基础设施建设成本使得其TCO较高，达到每公里3.99欧元，远高于电动巴士和改装电动巴士的成本。尤其是在氢气价格较高的情况下，氢燃料巴士的长期运行成本仍然是一个挑战。当前，氢燃料技术仍处于发展初期，未来技术进步和氢气供应链的成熟可能会逐步降低其成本。此外，报告还分析了影响TCO的关键因素，如巴士利用率和司机薪资等。在所有技术选项中，司机薪资占据了TCO的最大比重，几乎占到了每公里成本的三分之二。因此，巴士利用率的提高能够有效降低单位运营成本。报告还指出，不同机场的业务模式和运营需求将决定其选择哪种技术。例如，低成本航空公司偏向快速周转和高频率的地面运输，这会推动更多机场采用更高效、更具经济性的巴士技术。随着全球绿色能源政策的推进，越来越多的政府正在通过补贴和激励措施支持零排放巴士的推广。在欧洲、北美等地区，政府为零排放车辆和基础设施建设提供了40%-100%的资金支持，这无疑为机场的绿色转型提供了重要的资金支持。此外，未来随着电动和氢燃料技术的成熟，相关成本也有望进一步降低，推动地面运输的绿色化进程。总体来看，未来机场地面操作的绿色转型将呈现出逐步加速的趋势。随着电动巴士和氢燃料巴士技术的不断发展，基础设施的完善以及政策的支持，机场在实现碳中和目标的过程中，将能实现更高效的运营和更低的排放。而这些技术的成熟与普及，也将为全球航空业的能源转型奠定重要基础。​文档链接将分享到199IT知识星球，扫描下面二维码即可查阅！

OCR:WORLD ECONOMIC FQRUM DecarbonizingAviation GroundOperations: AlternativeBusTechnologies WHITEPAPER NOVEMBER2025

OCR:Contents Executive summary 3 Introduction 4 1 Operating buses at airports 5 1.1 Operating profile 5 1.2 Bus fleet ownership models 6 2 Airport bus solutions: Technology overview and developments 9 2.1 Technology options 9 2.2 Key features comparison 11 3 Tolal cost of ownership (TCO) analysis 14 3.1 Reference case study and scenarios considered 14 3.2 Scenario-based TCO resulls and insights 16 3.3 Sensitivity analysis 21 Conclusion 25 Appendix 1: Methodology 26 Appendix 2: Assumptions details per scenario 27 Appendix 3: Subsidies 29 Contributors 32 Endnotes 35 Disclaimer This document is published by the Worid Economic Forum as a contribution to a project, insight area or interaction. The findings, interpretations and conclusions expressed herein are a result of a collaborative process facilitated and endorsed by the Worid Economic Forum buf whose results do not necessarily represent the views of the Worid Economic Forum, nor the entirety of its Members Partiners or other stakeholders. 2026 Word Economic Forum. All rghts reserved. No part of this publication may be reproduced or transmifted in any form or by any means, including photocopying and recording, or by any information storage and retrieval system. Decarbonizing Aviation Ground Operations: Alter matve Bus Technoogie

OCR:November 2026 Decarbonizing Aviation Ground Operation Executivesummary Totalcostofownershipanalysisisa pragmatictooltoempowerairportsto advancestrategicdecisionsonnet-zero groundoperations. This paper explores the techno-economic feasibility Operational and strategic considerations: of replacing fossil-fuelled airport buses with The choice of technology depends on each alternative low-emission technologies such as airport's operational profile, financial capacity retrofitted diesel-to-electric, baftery-electric and and long-term sustainability goals. Sensitivity hydrogen buses. Ihe aim is to provide actionable analysis highlights that driver salaries, utilization insights for airports seeking to decarbonize ground rates and the avallability of subsidies are the operations and improve local air qualy. Using parameters that affect TCO the most. a robust total cost of ownership (TCO) model = validated through industry research and stakeholder While further research is recommended to assess interviews - the analysis explores how capital, more detailed airport load proflling, battery operating. maintenance and infrastructure costs degradation modelling and real-world retrofi affect airport bus operations and their costs. Key performance data, pragmatic recommendations findings include: for airports include: Technology assessment: Retrofitted diesel Adopting common electric vehicle (EV) charging vehicles with electric powertrains present a and hydrogen refuelling standards to streamline cost-effective transitional solution that enables infrastructure deployment and interoperability, rapid emissions reduction withoul the need including between ground equipment and future to procure an entire fleet of battery-electric aircraft. buses. Battery-electric buses offer zero tailpipe emissions and are increasingly cost- Integrating renewable energy sources to power competitive over their life cycle, especially where electric fleets and reduce life-cycle emissions, airport routes are predictable and charging and renewable transport fuels where reliance on infrastructure can be efficiently deployed and non-electric powertrains is envisaged. operated alongside flight schedules. Hydrogen buses (using fuel cell batteries or internal Exploring second-life battery applications combustion engines (ICE) provide greater range to maximize asset value, circularity and and faster refuelling. making them suitable sustainability. for larger airports with intensive duty cycles, though they currently face higher upfront and Leveraging public-private partnerships and infrastructure costs. green bonds to finance large-scale fleet transitions. TCO: The analysis, based on a reference European hub airport, reveals that retrofitted Enhancing collaboration among airports. electric buses can offer the lowest TCO per operators and energy providers to share best kilometre (km), making them attractive for practices and accelerate innovation. operators with budget constraints compared to newer diesel fleets. New battery-electric buses The paper concludes that decarbonizing bus require higher upfront investment but can deliver operations is both technically feasible and lower operating costs over time, particularly economically advantageous, positioning airports when supported by government incentives. as enablers in the broader energy transition of the Hydrogen buses, while operationally flexible, are aviation industry. By adopting a tailored, evidence probably the most expensive option at present oased approach, airports can also enhance due to technology and infrastructure costs operational efficiency while contributing meaningfully to the aviation industry's net-zero journey Decarbonizing Aviation Ground Operations: Altemative Bus Technologie

OCR:Introduction The aviation industry is committed to achieving required for decarbonization may benefit a wider net-zero emissions by 2050, with every actor = set of stakeholders, making airport master airlines, airports, ground handling companies and planning increasingly important for both aviation passengers - playing a critical role in this transition. and potential future oftakers who could leverage As global air passenger numbers are projected to the airport's energy transition. This broader grow at a compounded annual growth rate (CAGR) approach can strengthen the business case for of 3.6%, by 2050,1 airports worldwide will expand infrastructure upgrades. rapidly, especially in emerging markets. Major projects such as the Al Maktoum International This paper provides a practical tool for airports at Airport in Dubai, King Salman International Airport this transition point, focusing on a key use case: in Saudi Arabia and Istanbul airport in Turkiye are airport bus operations. Converting bus fleets is set to accommodate hundreds of millions of new a tangible and impactful way to reduce Scope 1 passengers annually, while new terminals and emissions, with many airports already piloting or expansions in Asia and Europe further underscore transitioning to new power trains. The airport bus this growth. market itself is undergoing rapid transformation; valued at $15.12 billion in 2024, it is projected This surge in passenger demand is driving to grow at a CAGR of 11.6% to reach $44.35 significant airport infrastructure investment, billion by 2033. Europe is expected to account including the transformation of ground operations, for over 37.8% of this market, driven by stringent Promising technologies for flight operations - environmental regulations and strong government such as sustainable aviation fuels (SAF) and support for electric and hybrid buses. novel propulsion aircraft (hydrogen and battery- electric) are advancing quickly, requiring parallel The analysis in this paper covers the main upgrades in airport infrastructure. While these technology options for airport buses that could technologies primarily address Scope 3 emissions reduce or eliminate tailpipe emissions: retrofitted (which typically account for over 90% of an airport's diesel buses, battery-electric buses and hydrogen emissions profile), there is also a growing focus on fuel cell buses. It compares the TCO and technical reducing Scope 1 and Scope 2 emissions from feasibility of each option, while recognizing buildings, vehicles and ground operations. Trialling that different airport archetypes, geographies on-the-ground decarbonization initiatives can also operations and ownership models will ultimately pave the way for battery-electric and hydrogen affect the feasibility and costs of new technology aviation, offering a practical means to test, adapt deployment. Other technologies, such as hydrogen and build familliarity with the technologies that may internal combustion engines (ICE), fossil fuel- eventually power aircrafft. biofuel blends and natural gas or biomethane buses, are not included in the quantitative analysis Airports serve as strategic nexuses not only but are considered qualitatively in the technology for aviation but also for the industries and alternatives discussion. Icommunities around them. Infrastructure changes Decarbonizing Aviation Ground Operations: Altemative Bus Technologies

OCR:Operatingbuses at airports Airport bus operations are influenced by several airport boundaries,requiring airports to operate factors including airport size, the number of longer routes. remote stands that require passengers to be transported between terminals and aircraff, All these factors affect the distance travelled and airport business model, the number of travellers utilization rate of the buses (typically known as transferring between terminals and the number of duty cycle), their Betime, maintenance costs and staff movements. ultimately their salvage value (the residual value of a bus when retired from service). This study considers In very congested international hubs, terminal these elements to better understand the TCO of expansions may have extended outside the original alternative propulsion technologies. 1.1|Operatingprofile Airport bus operations can be categorized into two distinct function within the airport ecosystem main groups: airside and landside, each serving a (see Figure 1) FIGURE 1 Landside and airside buses operations Landside Airside Airport accees Terminal Gates Remote stand Taxiways Runway Deoarbonizing Aviation Ground Operations:AltematveBus

OCR:Landside buses operate outside the securilty efficienl passenger flow. An example is Dubai perimeter and are primarily responsible for International Airport (DxB), which served more transporting passengers, staff and occasionally than 92 million passengers in 2024:" its 200-strong crew between airport terminals, car parks, public airside bus fleet transferred over 16,0o0 passengers transport hubs and other non-restricted areas. per month on average.a These services are integral to ensuring smooth access and connectivity across airport infrastructure In contrast, intermediate and regional airports for arriving and departing passengers. may rely on more modest bus fleets, typically ranging between 10 and 20 units. However, these Conversely, airside buses function within the regional airporls are usually constrained by gate secure area of the airport, facilitating the transfer infrastructure and may host high volumes of low- of passengers, crew and ground staff between cost carrier traffic that often prefers bus-to-stand terminal buildings and aircraft stands. Given the operations, to maximize rapid aircraft turnaround necessity to synchronize precisely with aircraft and cost-efficiency over the use of gates, which can turnaround times and boarding procedures, airside be more limited and expensive to operate. bus operations are subject to stringent safety and operational requirements. Operating hours at airports, often dictated by egislative restrictions,also impact bus operations. The configuration and complexity of both airside Airports with 24-hour schedules require continuous and landside operations vary significantly with the bus availability and maintenance. On the other airport's operational profile. This affects the number hand, airports under night-operating restrictions of buses operating at airports. For instance, in large may plan their activities in a different manner. These hub airports with multiple terminals, high passenger restrictions affect maintenance costs, bus lifespans volumes can require extensive landside bus staffing needs and refuel scheduling. networks to manage inter-terminal traffic and ensure 周92公以 福 1.2|Busfleetownershipmodels Airport ownership is a factor to consider for Airports' path to emissions-free bus operations preparing a decarbonization strategy and accessing could be significantly influenced by the underlying funding sources. Ownership models (private or business strategies that emerge from different state) may vary depending on region.* Approaches airport ownership models, but also from the bus to decarbonization can differ depending on the ownership models directly. At a fundamental level. ownership model: government-funded airports three dominant categories prevail (see Figure 2): often operate within the framework of national or direct ownership of bus fleet and operation by the regional policies, whereas privately owned airports airport authority; outsourced provision through may have greater flexibility to define strategies concession agreements; and third-party contracts according to their operational or market context and hybrid approaches combining both. Decarbonizing Aviation Ground Operations: Altemative Bus Technologies

OCR:FIGURE2Bus operations'ownership modelsexisting at airports Direct ownership Third-party and hybrid Outsourced provision through and operation arrangements concession agreement Probably the less common of the models is when Lastly, hybrid models are increasingly common, the airport authority - often a public entity or vertically especially in large or multi-terminal airports where integrated airport operator - fully owns the bus fleet different operational needs coexist. Under this and directly manages all related operations. While this approach, the airport may retain direct control over approach allows for high levels of operational control strategically critical services, while outsourcing and strategic alignment with broader objectives such landside or non-core services to external providers. as decarbonization, il frequently leads to a higher rate This configuration allows airports to maintain control of capital expenditure, alongside long-term financial over certain aspects of operations such as safety. and operational commitments. security or integration, while benefiting from the efficiency and scalablity of outsourced services Airports more commonly employ a concession- in less *sensitive" areas. This model ultimately based model for bus services, wherein private requires well-defined governance structures and contractors may be granted exclusive rights to performance monitoring mechanisms to ensure operate bus fleets for a defined period in exchange coherence across service providers. for a fee and may be required to comply with certain fleet requirements, sustainabilty criteria and performance guarantees. Pragmatically, this Theinfluenceofairlines system allows airports to incorporate bus services inbusoperations into broader ground handling contracts, where operators are responsible for a range of ramp, baggage and passenger transportation services The business models of the airlines served by the under a unified framework. airport also have a direct bearing on bus operations and contractual arrangements. Low-cost carriers In addition, airline business models at the airport (LCCs), for example, offten priorilize fast turnaround directly impact bus services and contracts. In times and minimal ground service fees, influencing the negotiating mix among service providers the design of bus operations towards high- airlines and airports, the latter often maintain frequency, low-cost solutions that maximize aircraff decision-making over the infrastructure needed for utilization. LCCs frequently utilize remote stands to enabling ground operations, as well as the energy reduce airport charges, thereby increasing reliance consumption and demand associated with this. This on airside buses. Consequently, ground handling create6 potential avenues for the airport to influence contracts that include bus operations must be investment in greening bus fleets (undertaken calibrated to align with the cost sensitivities and by third parties) through investment in green infrastructure, such as electric charging stations, or operational rhythms ot these carriers through local emissions and air quality standards. Deoarbonizing Aviation Ground Operations: Aitemative Bus Technologie

OCR: In contrast, legacy airlines may demand tighter and a need for airports to establish robust integration with lounge and gate infrastructure. oversight mechanisms to ensure safety, quality and All these factors affect bus service coordination interoperabilty across competing providers. As a between airlines, airport and ground service resulf, procurement processes have become more providers. Therefore, airports serving a diverse structured, often requiring competitive tenders, airline mix may adopt hybrid ownership and multi-year service-level agreements and detailed operating models that can accommodate varying performance metrics. Ultimately, all these factors service expectations and turnaround profiles may become barriers if an airport is willing to change the infrastructure needed for changing the bus fleet. Regionalregulationsimpacting theownershipmodel In sum, the business and ownership models of airport bus fleets are neither static nor one-size-fits- all. They reflect a complex interplay of operational In some cases, regulatory frameworks largely configurations, commercial imperatives and determine the model adopted. In Europe, for regulatory constraints. As airports intensify efforts to instance, the European Ground Handling Directive* reduce their environmental footprint, these models plays a critical role in shaping market access and must be carefully assessed and leveraged to pursue service provision models. The directive mandates the path of least resistance to meaningful progress the liberalization of ground handlling services, in sustainability. When fleet decarbonization is allowing multiple service providers to compete in elevated to a strategic priority, public-private eligible commercial airports in this case, those partnerships and the shift from asset-based with annual traffic exceeding 2 million passengers ownership to service-orienited mobility contracts or 50,000 tonnes of freight. This has led to increasingly come to the fore - a development increased outsourcing, greater price competition further examined in Chapter 4.

OCR:Airport bus solutions: echno logyoverview and developments Ground transport - particularly bus fleets - has fuel cell and retrofitted diesel vehicles with battery- become a key tocus tor airports seeking to reduce 9lectric powertrain. Renewable biofuel (hydrotreated operational emissions and advance sustainability vegetable oll, or HVO) and biomethane buses, goals. Rapid technology developments are driving a although not considered in the TCO model, have reassessment of fleet strategies and the adoption of also been assessed. By examining the operational innovative solutions. characteristics, infrastructure requirements and decarbonization potential of each option, this chapter This chapter provides an overview of the main aims to equip decision-makers with the insights technological pathways considered for the TCO heeded to navigate the complex landscape of analysis that are shaping the future of airport bus echnology options and align investments with both operations, including battery-electric, hydrogen immediate needs and long-term climate objectives 2.1Technologyoptions The decarbonization of airport bus fleets is are particularly well-suited to airports with compact increasingly shaped by three primary technologies: layouts, predictable routes and scheduled breaks battery-electric, hydrogen fuel cell and retrofitted that align with charging opportunities. Overnight diesel depot charging is often sufficient for landside shuttle services, while high-power opportunity charging can Each option offers distinct operational characteristics support airside operations with higher duty cycles. and infrastructure requirements, making its suitabily dependent on the specific operational context of the However, battery-electric technology is not airport. While their shared objective is the reduction without limitations. Range and battery lifetime of greenhouse gas emissions and local pollutants, can be affected by ambient temperature, heavy the underlying technologies differ significantly in passenger loads and continuous use of auxiliary energy storage, refuelling or recharging methods, systems, with performance degradation more and performance profiles pronounced in extreme cold or heat. Charging infrastructure requires careful integration with airport Understanding the core features of each technology power systems to avoid grid strain, potentially and weighing it with financial considerations can necessitating upgrades to accommodate the rising 9nable decision-makers to achieve a full techno energy demands, or the deployment of energy economic picture guiding strategic investment. storage solutions at airports. In addition, strategies for end-of-life battery management and disposal remain a critical consideration; some airports Electricbuses are already adopting *second-ffe* applications,” repurposing retired batteries for stationary storage, which can help mitigate environmental and logistical Battery-electric buses draw propulsion energy from challenges if properly implemented. high-capacity lithium-ion or, in emerging cases, solid-state batteries, offering zero taipipe emissions Airports implementing electric buses must consider and high energy efficiency. the operational fit, route length, fleet size and the ability to coordinate charging with operational peaks. Their primary advantage is the relative maturity Electric buses have seen rapid adoption, especially in of the technology thanks to the rise of EVs in the European airports such as Aeroporti di Roma, where automotive industry, and the rapidly expanding renewable energy powers 11 fully-electric shuttle supply chain, which has driven down procurement buses,7 or London Gatwick,# which will entirely costs and improved performance. Electric buses replace ils 14-bus fleet with fully electric buses Decarbonizing Aviation Ground Operations: Altemative Bus Technologie

OCR:Hydrogen Retrofittedbuses Hydrogen fuel cell buses convert gaseous hydrogen Retrofitted diesel buses offer a transitional into electricity through an electrochemical reaction, decarbonization pathway by replacing the internal emiltting only waler vapour from the tailpipe, which combustion engine and associated components can be collected for later use. One of their principal with alternative powertrain solutions most advantages lies in operational autonomy: hydrogen commonly full battery-electric, but potentially also vehicles lypically achieve ranges of 350 to 500 hydrogen ICE. or hybrid systems that combine km on a single refuelling, which is particularly combustion and electric drivetrains (including advantageous in large airports with extended apron plug-in variants). For the purposes of this analysis, networks (where buses are specialized vehicles however, only the conversion from diesel to full used to transport passengers between terminals battery-electric is examined in detail. and aircraff) or where buses operate on multi-shift cycles with minimal downtime. This intermediate solution is particularly interesting for airports with a relatively new bus fleet (fossil- Moreover, hydrogen systems can deliver consistent fuel or biofuel based). This allows them to extend power output regardless of ambient temperature, the operational life of their fleets while achieving allowing auxillary systems such as air conditioning substantial reduction in tailpipe emissions, avoiding or cabin heating to operate without significantly the capital cost of procuring entirely new vehicles compromising range = an important consideration (a retrofitted bus could cost signiicantly lees than in airports located in extreme climates or where the price of a brand-new electric one). From a passenger comfort requirements are stringent. technical standpoint, retrofitting can be completed Refuelling is rapid, often under 15 minutes, enabling in a fraction of the time required for full fleet high vehicle availabiity and reducing the need for replacement, and it enables the reuse of bus bodies large spare fleets. and chassis and leaves the interiors in serviceable condition. The main opportunities lie in legacy Operationally, hydrogen buses are particularly fleet decarbonization where budget constraints sulted to airside use cases where flexibility. long long procurement cycles or sustainabiity targets duty cycles and reduced turnaround times are demand rapid emissions reduction. critical, and where land availability allows for the installation of a dedicated hydrogen refuelling However, retrofitting presents challenges: the facility.For instance, Greater Toronto Airports diversity of existing fleet specifications can Authority's plan for hydrogen bus adoption is complicate conversion processes, certification strongly linked with the airporl's wider ecosystem,9 requirements may vary by jurisdiction, and benefiting from the installation of a hydrogen maintenance teams could require retraining to refuelling station outside of airport boundaries for manage the new systems light and heavy-duty vehicles. Decarbonizing Aviation Ground Operations: Altemative Bus Technologies

OCR:Additionally, airports considering this as a solution technology. These deployments are enabling may double-check if, after the retrofit, the bus airports to achieve immediate emissions reduction fleet would achieve the same efficiency, range while longer-term electrification and hydrogen and reliability compared to purpose-built zero- infrastructure are developed. emission vehicles, particularly in demanding airside environments. Biomethane-poweredbuses Geneva Airport1 illustrates the potential of this approach: in 2024 I invested in two retrofitted buse6 at an average cost of CHF 350,000 each, with four This alternative uses methane produced from more to be delivered in 2025. Together with other biological sources, such as organic waste, leet measures, this brings the airport to 24 electric sewage sludge or agricultural residues, which is buses in a total of 27, showing how retrofitting can used as a drop-in replacement for compressed provide a cost-efficient bridge while infrastructure fol or liquefied natural gas in standard gas engines next-generation technologies is developed or hybrid systems. lt enables airports and transit operators to decarbonize their fleets without completely replacing existing vehicles or refuelling Fossil-fueland biofuel-mixbuses nfrastructure. Biomethane buses have quick refuelling times, long operational ranges and significantly lower particulate and nitrogen oxide HVO buses represent a growing trend in airport emissions compared with diesel. When the ground transport decarbonization strategies. HVO biomethane is sourced from waste streams, the is a renewable diesel alternative produced from overall greenhouse gas balance can approach vegetable oils or waste fats, offering a significant carbon neutrality. reduction in life-cycle carbon emissions = up to 90% compared to conventional diesel. These fuels The Munich Airport's biomethane buses2 have are in most cases compatible with existing diesel a range of up to 800 km and refuel in about five engines and fuelling infrastructure, making them minutes. They have reduced particulate emissions a practical and immediate solution for airports11 by roughly 90% and nitrogen oxides by over 60% seeking to lower their operational emissions without compared with Euro VI diesel buses extensive new infrastructure investments. From an infrastructure perspective, HVO’s Hydrogen internal compatibility with existing diesel fuelling systems means that airports can transition their fleet combustionengine with minimal operational disruption or capital expenditure. This contrasts with the previously Hydrogen ICE is another retrofit option under analysed scenarios. As such, HVO serves as a development, showing promise particularly as a valuable bridge technology, supporting airports bridge between existing diesel engines and zero- decarbonization goals in the near term and emission technologies, since many components complementing the broader shift towards SAF and (such as ignition, cooling and transmission) are zero-emission ground transport. shared with conventional buses. While this paper has focused on zero-emission Projects such as the TRIMIS HyFLEET:CUTE1 trials technologies such as battery-electric and in Berlin have already demonstrated the potential hydrogen fuel cell, HVO-powered buses have of this approach. While hydrogen ICE has not been not been included in the core analysis due to included in the present TCO analysis, it is an area their status as a low-carbon, rather than zero- worth tracking, and its evolution could be captured emission, solution. Nevertheless, it is important to in future assessments to provide a more complete acknowledge that HVO buses are being adopted picture of available decarbonization pathways. at a growing number of airports as a transitional 2.2|Keyfeaturescomparison As airports advance on their course fowards the decision to adopt one pathway over another decarbonization, the choice of bus technology is requires a careful analysis of each airport's unique more than a technical decision - it is shaped by perational constraints, infrastructure readiness, evolving priorities, operational realities and the egulatory environment and TCO. Figure 3 ambition to create a cleaner future epresents how these options compare in terms of climate impact, investment, ongoing costs and Across all available technologies = diesel, retrofit operationaI fit. diesel, battery electric and hydrogen fuel cell - Decarbonizing Aviation Ground Operations: Altemative Bus Technologies 11

OCR:FIGURE3|Cross-technologycomparisonofbusesbased onclimate impact, operatingcosts,investmentsandairportoperations CategoryCriterion Diesel Retrofit Electric Hydrogen Climate impact COemissions during operation High Zero Zero Zero Energy consumption High Medium-High Medlium-High Medium Fuel/Energy source Diecel Electricity Electricity Gaseous hydrogen Upfront cost and investment Airport bus market availability Global, >15 OEMs* Growing. ~10 OEMs and >10 OEMs,expanding ~5 OEMs, limiled retrofit specialists rapidly models, pilot projects Infrastructure requirements Diesel stations Charging stations Charging stations Gassous hydrogen station Technology maturity High Medium Medium Low Ongoing operating costs Maintenance requirements High Medium Low Medium Expected service lifetime 15-20 years 10-15 years (battery 12-18 years (battery replacement required) replacement required) 12-18 yeers Ongoing operating costs Airport planningimplications Minimum Grid upgrade Grid upgrade Hydrogen ecosystem Operational range Long Medium Medium Long Short/Medium Short/Medium Short (minutes) Fast charging<25 min Refuelling/Charging time Fast charging <25 min Overnight charging 3-4 Overnight charging 3-4 Short (~10 min) hours hours Driver/User acceptance Medium Medium High (raining needed) High (training needed) Note: OEMs: Original equipn Climateimpact highlighting that the climate impact is not just abouf the bus fleet itself, but about the energy ecosystem that supports it The environmental story of airport buses begins with diesel, a technology that has reliably powered fleets for decades but now stands as the Upfrontcostsandinvestment benchmark for emissions and energy consumption. Diesel buses, while robust and familiar, are the primary ground transport contributor to greenhouse When looking at their upfront costs, dlesel buses gas emissions and local air pollution at airports. remain the most accessible and affordable option Retrofitting these vehicles with electric powertrains for many operators. Their widespread availability offers a meaningful step forward - reducing and mature supply chains keep purchase prices emissions and energy use. low. Retrofitting diesel buses offers a pragmatic alternative for airports with newer fleets, enabling The real transformation comes with battery electric emisslons reduction at a lower cost than purchasing and hydrogen fuel cellbuses. Both technologies new vehicles. While often presented as costing promise zero emissions at the point of use, around half the price of a new bus, actual expenses fundamentally changing the airport's environmental can vary significantly depending on the age and footprint. Battery electric buses can reduce condition of the base vehicle. Older units typically greenhouse gases and local pollutants dramatically, require extensive refurbishment - replacing major especially when powered by renewable electricity. components and sometimes refitting interiors, Hydrogen buses also offer clean operation, emitting Additional logistical expenses, such as transporting only water vapour, but their broader climate benefit buses to specialized refurbishment centres, depends on how the hydrogen is produced. If add further to the investment. Moreover, the sourced from renewables, the impact is profound retrofit market, though expanding, remains less if not, some of the environmental gains are offset standardized than that for new electric buses Decarbonizing Aviation Ground Operations: Altemative Bus Technologies 12

OCR:Battery electric buses represent a new era of However, electric buses are quieter and cleaner, investment. The vehicles themselves are more enhancing the passenger and staff experience and expensive than diesel ones, and the need for reducing the airport's environmental footprint. charging stations - and related signiicant upgrades to airport electrical systems, including grid upgraded Hydrogen buses offer the promise of long range and battery storage systems = can make the initial and rapid refuelling. combining the operational outlay substantial. Yet, as the market matures and flexibility of diesel with the environmental benefits more manufacturers enter the space, costs are of electric. While the lack of widespread hydrogen gradually coming down and the long-term value infrastructure remains a challenge, the introduction proposition is improving of hydrogen also requires tailored training and safety protocols - comparable to the adjustments Hydrogen buses, meanwhile, are at the frontier of already made for other fuels such as electricity, innovation. Their high purchase price and the need diesel. propane or natural gas. Airports investing for specialized, often bespoke, fuelling infrastructure in hydrogen are already demonstrating that it can make them the most capital-intensive option. For be deployed safely and reliably, with affordability airports considering hydrogen, the decision is expected to improve as adoption scales. as much about future readiness and ecosystem development as it is about immedlate cost. Beyond these day-to-day operational factors, the transition to battery-electric and hydrogen buses ntroduces a new layer of complexity and uncertainty Ongoingoperatingcosts for airport operators. An industry taskforce led by Airports Council International (ACl) Word suggeste several steps to tackle these, including: Diesel buses, while cheap to buy, can be more expensive to run than other options. Fluctuating fuel A comprehensive aerodrome compatibility prices and the maintenance demands of combustior study before operations can begin, ensuring that engines add up over time. Retrofited buses can infrastructure, safety and operational procedures offer some relief, with newer components reducing are fit for purpose not only for buses, but also in maintenance needs, but they stillface the dual coste anticipation of future hydrogen or electric aircraft. of diesel and electricity, especially when airports choose to have both system coexist for a while. Security and fire safety, as both battery and hydrogen vehicles present unique risks. Battery Battery electric buses, by contrast, shine in terms fires can be prolonged and emit toxic fumes, of ongoing cost efficiency. Electricity Iis generally while hydrogen, though clean burning. demands less expensive and more stable in price than diesel specialized detection and response protocols. and the simplicily of electric drivetrains can mean fewer breakdowns and lower maintenance bills. Airports must also plan for significantly increased Over the lifespan of the vehicle, these savings can electrical power demand, as stands will need be significant, helping to offset the higher upfront to support simultaneous charging of buses and investment. Hydrogen fuel cell buses also benefit eventually, aircraft - potentially necessitating major from reduced mechanical complexity, but the cost upgrades to energy infrastructure. and availabiity of hydrogen fuel remain barriers. As the technology matures and the hydrogen supply The introduction of new fuel types may require chain grows, these costs may fall, but for now, they segregated parking stands, which could reduce are a key consideration. stand capacity and complicate ground support squipment logistics. Airportoperations Furthermore, operational procedures such as verifying electrical connections before energizing cables, and reassessing stand design and risk management, Diesel buses are easy to refuel and maintain become critical to ensure safety and resilence and well-suited to established operational routines. Retrofitted buses fit comfortably into this Ultimately, while each technology presents a distinct pattern, requiring only modest adjustments to balance of environmental benefits, operational accommodale charging. Still, the need to remove considerations and investment requirements, the vehicles from service for conversion and the decision for any airport wil depend on how these logistics of refurbishment can create temporary factors translate into long-term value. To provide a capacity gaps that airports must plan for. Clearer basis for comparison and support evidence- based decision-making, the next section delves into Battery electric buses introduce new dynamics. the total cost of ownership (TCO) analysis - outlining Charging schedules must be carefully managed to the methodology, key assumptions and resulting ensure vehicles are ready when needed, and route nsights that underpin a comprehensive evaluation planning may need to adapt to range limitafions of each pathway's financial and operational especially in airports with demanding duty cycles implications over the fullife cycle of the fleet Decarbonizing Aviation Ground Operations: Altemative Bus Technologies 13

OCR:Total cost of ownership TCO) ar The TCO analysis presented in this paper evaluates infrastructure, and any necessary modifications the high-level economic implications of adopting to existing facilities, such as maintenance depots different sustainable bus technologies in the airport or fuelling stations. Opex covers the recurrent environment, considering both capital expenditure costs incurred during operation, including fuel or (capex) and operational expenditure (opex) across 9lectricity supply, scheduled and unscheduled the expected service life of the vehicles maintenance (including battery replacement), staf training. insurance, licensing and other ongoing Capex includes the upfront costs associated with operational expenses, vehicle procurement, 3.1|Referencecasestudyandscenariosconsidered To ensure a simple comparison between alternative 2025 and quantitaitive research, some operational bus technologies, this study has chosen the parameters (e.g. bus distance travelled) have been archetype of a European international hub airport. sstimated and validated to ensure the analysis can It has been assumed that a similar airport may be as representative as possible of potential real- operate a 50-airside bus fleet. Leveraging over 20 world applications. The full methodology is set out interviews with Airports of Tomorrow and aviation in the appendix. stakeholders conducted from March to August TABLE 1 Reference caseparametersforthe Europeaninternational hubmid-sized airport Operationalparameter Value Comment Fleet size (number of buses) 50 Number of drivers (per bus) 3 Bus driver salary (E/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 x average 6peed 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 airporis16 Corporate borrowing rate (%) 4.10 Based on European Central Bank (2025) datats Banking department amount 0 Full investment assumed to be made upfront considered (%) Decarbonizing Aviation Ground Operations: Altemative Bus Technologies

OCR:Operational details are harmonized, and all of Based on market research, each bus is assumed to these have been kept fixed across all technology have a 3B6 kilowatt-hour (kWh) battery, providing scenarios. lt is assumed that buses travel at an a usable range of 235 km and a daily charging average speed of 20 km per hour within airport load of 103.45 kWh. Charging is conducted grounds, ensuring realistic energy consumption and overnight, with a 3.82-hour average charging time maintenance estimafes. Buses operate 18 hours and 95% charger efficiency. Maintenance costs a day, but carry passengers only for 25% of the are typically lower than diesel when excluding operating hours (utilization rate 25%), every day of battery replacement. In this analysis, this battery the year, with an estimated bus range of g0 km/ replacement is assumed to happen in year nine. day. Staffing is standardized, with three drivers per To reflect potential grant schemes and incentives bus per day, each earning a fixed annual salary of aimed at supporting low-emission bus deployment. E36,580. A 15-year project lifetime is assumed, 50% of the capital investment is assumed to be and financial calculations are thus discounted subsidized by the government. This scenario at a weighted average cost of capital (WACC) signilicantly reduces emissions and aligns with long rate of 4.56 %, aligning with industry norms for lerm sustainabiity goals, though it requires higher infrastructure investments. upfront investment and operational adjustments. In this reference case study. airport bus operations continue to rely on a conventional diesel-powered Scenario3 fleet. This approach requires the least infrastructure Hydrogen busfleet-off-site investment, as il leverages existing fuelling and hydrogenproduction maintenance facilities. The capex is primarily allocated to the procurement of diesel buses, while This scenario considers the deployment of the opex is dominated by fuel costs, driver salaries. hydrogen-powered buses, with hydrogen supplied warranty and insurance, and maintenance. Market from off-site production facilities. The bus fleet average retail price of diesel is assumed at 1.67 operates approximately 4,500 km per day. per litre and the unit price per bus is 259,000, with consuming 428 kilograms (kg) of hydrogen daily, no government subsidies considered. taking average hydrogen bus fuel economy in mind. Each bus is equipped with a 30-80 kg hydrogen Taking into account the various technology tank, offering a range of 200-600 km per refuelling. options, the following scenarios have been with refuelling times between 10 and 20 minutes. developed based on the key criteria that influence Based on market research, the average capital cost decision-making in airport master planning per bus is 600,000, with a 3.5% annual learning curve and 50% government subsidy on bus capex. Scenario1 All investments are made upfront, and a dedicated Retrofitted electric fleet refuelling station is installed at the airport. In line with aviation decarbonization ambitions, In this scenario, the airport opts to retrofit existing the baseline assumption for this scenario is the diesel buses with electric drivetrains, offering a use of green hydrogen, priced at 2.87/kg. The transitional pathway towards electrification. The TCO model can,however, also reflect alternative retrofit cost is assumed at 50% of a new electric hydrogen price assumptions (e.g- grey or blue bus, with mainitenance costs 10% higher than those hydrogen), allowing adaptation to different regional of new electric buses (E0.407 per kilometre). The contexts and production pathways. This scenario operational and infrastructure requirements mirror enables rapid refuelling and extended range those of the new electric fleet, including charging supporting operational flexibility infrastructure and driver training Scenario2 Electric fleet This scenario explores the transition to a fully electric bus fleet, requiring significant investment in both vehicles and charging infrastructure. The capital expendilure includes the purchase of electric buses (average price 550,000) and the installation of charging stations, with adlditional costs for civil engineering. grid updates, electrical installation and design. Operational expenditure covers batffery replacement, charging costs, driver salaries, warranty and insurance, maintenance and driver raining Decarbonizing Aviation Ground Operations: Altemative Bus Technologies 16

OCR:3.2|Scenario-basedTCOresultsandinsights This section presents a detailed TCO comparison infrastructure is required. Annual operating for the four alternative bus fleet scenarios at a expenditure is 5.3 milion, with a 15% salvage European international hub airport (see Figure 4) ralue factored in at end-of-life. The analysis covers initial investments, annual operating expenditures, TCO per km, and TCO is influenced by high fuel and maintenance scenario-specific operational insights. costs. The absence of government subsidies and exposure fo volatile diesel prices can erode long-term The diesel-based fleet serves as the baseline for competitiveness. Notably, driver salaries represent comparison. The initial investment is E11.97 million, the single largest cost component, accounting for exclusively for bus procurement, as no additional nearly two-thirds of TCO per km. FIGURE4 TCO results divided by scenario,teohnology,capex and opex Operational assumptions Financial assumptions Airport type Fleet size (#) Daily km Operating hours Utiization rate (%)Drivers (#) Driver salary (e) WACC' Lifetime Year of investment International EU 50 90 per bus 18 per day 25% 3 per bus 36.5k yearly medium-sized 4.56% 15 years 2030 Diesel Retrofit Electric Hydrogen Total capex 11.97 million 5.11 million 9.30 million* 18.47 million* Capex/km 0.49 /km 0.20 /km 0.37 /km 0.35 /km Annualopex 5.30 milion 4.95 million 4.91 million 5.45 million Opex/km 3.22 E/km 3.00 E/km 2.98 E/km 3.64 /km TCO/km 3.71 /km 3.20 /km 3.35 /km 3.99 E/km Note: Key operational and financial 1 Weighited average cost of caipital * Afler 50% subsidly 5 0101 0101 viation Ground Operations:Aitermative Bus Technobge 010

OCR:FIGURE 5|TCOresultsforall scenarios,perkilometre Dieselbuses 4.00 E/km 2.38 3.71 3.50 /km 3.00 /km 2.50/km 2.00 /km 1.50 /km 0:49 1.00 E/km 0:44 0.50/km 0.41 0.00 /km Diesel cost Bus maintenance Bus Bus driver Total Retrofittedbuses 3.50 /km 2.38 3.20 3.00 E/km 2.50 /km 2.00 E/km 1.50 /km 1.00 /km 0.17 0.50 0.50 /km 0.05 0.10 0.00 E/km Charging infrastructureElectricity cost Bus maintenance Bus Bus driver Total Decarbonizing Aviation Ground Operations: Altemative Bus Technologies 17

OCR:Electricbuses 4.00 /km 3.50 /km 2.38 3.35 3.00 /km 2.50 /km 2.00 /km 1.50 /km 1.00 /km 0.34 0.48 0.50/km 0.05 0.10 0.00 /km Charging infrastructureElectricity cost Bus maintenance Bus Bus driver Total Hydrogenbuses 4.50 /km 4.00 E/km 3.11 3.99 3.50 /km 3.00/km 2.50/km 2.00 E/km 1.50 /km 1.00 /km 0.53 0.50 /km 0.35 0.00 /km Fuel (LH,) Refueling station Bus Total Decarbonizing Aviation Ground Operations: Altemative Bus Technologies 18

OCR:While the initial investment on the conversion The electric bus fleet scenario leverages a 3.9% of existing diesel buses to electric drivetrains is annual learming rate for e-bus costs and a 50% E5.11 million for retrofitting. the annual operating government subsidy on capex, which helps offsel expenditure is E4.95 million, and a 25% salvage the higher initial outlay. Battery replacement is value is assumed. a signilicant cost in year nine, where the model las assumed that this important maintenance is Retrofitting offers a pragmatic, lower-cost pathway happening at the same point in time for retrofitted and to electrification, with the lowest initial capital outlay electric buses, as the maturity of the technology is among all scenarios (see Figure 6). The retrofit cost equivalent. TCO per km (see Figure 5) is slightly higher is set at 50% of a new electric bus, and 50% of than in the retrofitted scenario, mainly due to higher capex is subsidized by government support. The capex, but still substantially lower than diesel or scenario assumes a 2:1 bus-to-charger ratio (each hydrogen, when factoring in governmenit grants. The charger supporting two buses) and incorporates a scenario is well-aligned with long-term sustainability significant battery replacement cost (35% of bus and regulatory objectives, offering a balance between price) around the ninth year: While maintenance operational efficiency and environmental performance costs are slightly higher than for new electric buses the overall TCO is close to the battery-electric case If the technology of choice is hydrogen (supplied and potentially lower when factoring in government from off-slte production), this scenario requires the incentives, making this scenario particularly highest initial investment, particularly for vehicles and attractive for operators seeking to decarbonize with refuelling infrastructure. The total estimated capex is limited budgets and minimal operational disruption. 18.47 million, split between 12.52 million for bus The relatively low electricity and infrastructure purchase, and E5.96 million for the refuelling station. costs further enhance the cost-effectiveness of Annual opex is E5.45 million, with driver salaries and this scenario. hydrogen fuel costs as major contributors. While the refuelling station's upfront capex is modest relative If the boundary conditions and the economic to the bus fleet, its opex remains low. The scenario's wealth of the airport make it feasible to invest in TCO is driven by high driver costs and the relatively a new purpose-built electric bus fleet, the initial high cost of hydrogen fuel compared to electricity. investment is assumed to be f9.3 million for buses (including approximately E1 milion for charging However, hydrogen offers operational flexibiity and infrastructure, with the remainder allocated to rapid refuelling. which may be advantageous for vehicle procurement). Annual operating expenditure high-utilization or long-range applications. While the is 4.91 million, considering a 25% salvage value at economics remain challenging without cost reduction end-of-life (as in the previous case). or policy support, potential revenues from carbon trading mechanisms, such as the European Union's While the upfront investment is higher than for Emissions Trading System (ETS) could strengthen retrofitting. the new electric fleet benefits from the business case. The availabiity and treatment of mproved reliabiity, advanced features and lower such credits, however, depend on evolving policy maintenance costs. frameworks, and may not apply equally to other technologies such as baftery-electric buses.

OCR:FIGURE 6|TcOresults comparison acrosstechnologiesdividedbycapexand opex TcOresultscomparisonacrosstechnologies Totalcostofownershipperkm dividedbycapexandopex 20m 4.50 18.47m 18 m 4.00 3.99/km 3.71/km 16 m 3.50 —3.35/km 3.20/km 14 m 11.97m 3.00 12m 2.50 10m 9.30m 2.00 8m 5.11m 5.30m 5.45m 1.50 6m 4.91m E4.95m E4 m 1.00 2m 0.50 0 m Electric Retrofitted Diesel H,offsite Electric Retrofted Diesel H,offsite electric liquefaction electric liquefaction Total capex Total annual opex Capex/km Opex/km DeoarbonizingAvintionGroundOpe

OCR:3.3|Sensitivityanalysis To account for uncertainty and variability in existing Certain variables, such as bus driver salary, utilization datapoints, the model assumptions (that could rate and government subsidies, are significant drivers change depending on regional and operational of cost across all technologies. Driver salary, in dynamics) and future cost.trajectories, a scenario particular, represents a substantial share of operational and sensitivity analysis was also undertaken. expenditure. Utilization rate defined as the proportion Geographical factors, market dynamics and of time a bus is actively in service carrying passengers operational needs can affect the assumptions directly impacts the amortization of fixed costs and is used for the analysis, requiring flexibiity in the a key determinant of LCO for all scenarios. The longer assessment performed. This sensitivity analysis thus a bus is in service carrying passengers, the more its aimed to identify the key variables influencing the fixed costs are spread out, lowering the overall cost levelized cost of ownership (LCO, /km) for each per km. Conversely, if buses are used less, the cost bus technology scenario: diesel, retrofitted, baftery per km can rise dramatically, sometimes by as much electric and hydrogen (see Figure 7). as 300% for some of the technology scenarios. FIGURE7 Sensitivity analysisforeach technology scenario Main parameters driving levellized E/km price Diesel busTCOsensitivity Common Acroes Options 3.71E/km (Baseine) Bus utilization (%) 38 18 Bus driver salary (e) 25.6k 54.87k WACC (%) 6.56 2.56 Diecel bus unit price (E) 150k 350k Diecel fuel price (E/litre) 1.08 2.26 Diesel bus fuel consumption (/km) 0.4 Diecel bus maintenance cost (E/km) 0.57 0.69 2.50 3.00 3.50 4.00 4.50 5.00 5.50 E-bus TCO sensitivity 3.35E/km (Baseline) Bus utilization (%) 38 18 Bus driver salary (E/driver) 516 54.87k EV bus govermment subsidy (%) 口 WACC (%) 6.56 2.56 EV bus unit price (E) 368k 750k Year of investment 2050 2050 Electricity price (E/kWh) 0.09 0.30 EV bus battery replacement cost (% of new bus price) 25 Charging station number of unit R EV bus maintenance cost (E/km) 0.30 0.43 2.50 3.00 3.50 4.00 4.50 5.00 5.50 Deoarbonizing Aviation Ground Operations: 2

OCR:RetrofittedE-busTCOsensitivity 3.20E/km (Baseline) Bus utilization (%) 38 Bus driver salary (E/driver) 25.6k WACC(%) 5 EV bus government subsidy (%) 6.56 EV bus unit price (E) 368 Electricity price (E/kWh) D.09 0.30 Year of investment 2050 2025 EV bus battery replacement cost (% of new bus price) 45 Charging station number of unit EV bus maintenance cost (E/km) 0.30 0.43 2.50 3.00 3.50 4.00 4.50 5.00 5.50 HydrogenbusTCOsensitivity Bus utilization (%) 37.5 17.5 Bus driver salary (E/driver) 25.6k 54.87k Hydrogen price (E) 10.5 FCEV bus govemment subsidy (%) 60 WACC (%) 6.56 .56 Refueling station capex (E) 3.9 8.5 FCEV bus adljusted unit price in 2030 (E) 350k 751k FCEV bus maintenance cost (% annual opex 30 63 Refueling station operational costs (% annual opex) 5 2.50 3.00 3.50 4.00 4.50 5.00 5.50

OCR:Government subsidies and incentives are another hydrogen supply - linked to hydrogen production critical factor shaping TCO. Airports and ground infrastructure - can impact opex. For airports service equipment providers have access to a wide considering hydrogen buses, a more detailed range of support schemes for zero-emission buses issessment of both technology readiness and and related infrastructure. In North America and uel supply logistics is recommended to ensure Europe, programmes frequently cover 40-100% efficient fleet operation. These insights highlight the of the incremental costs for vehicles and charging importance of careful planning and local context infrastructure through grants, rebates or tax credits when choosing and managing alternative bus Notable examples include the Federal Aviation technologies at airports. Administration (FAA) Zero Emissions Airport Vehicle Programme (United States), the Zero Emission Transit Fund (Canada) and the EU Alternative Fuels Additionalreflections Infrastructure Facilty (European Union), all of which provide substantial support tailored to airport projects. Additional opportunities often exist through The transition to hydrogen-powered ground state, provincial or utility-level programmes. operations is already challenging. but this takes place while air transport is also exploring this In the Gulf region, while open-call grants are less technology.with significant opportunities for common, support is provided through government collaboration but also complex chalenges, While led pilot projects, procurement mandates and some airports are currently studying infrastructure strategic partnerships aligned with national planning for supporting hydrogen bus fleets sustainability strategies. Non-monetary incentivee = primarily through gaseous hydrogen supply such as tax breaks are also frequently offered, future demand from hydrogen-powered aircrafft further improving the financial case for adoption will require a fundamental shift in both scale and A detailed table of available subsidies and technology, particularly towards liquid hydrogen incentives across regions is included in the (LH,) production, storage and handing. appendix for reference. A key observation is the current disconnect between Each bus technology also has its own unique hydrogen infrastructure for ground vehicles and sensitivities. For example, the cost of fuel is the anticipated needs of aviation. As hydrogen especially important for diesel buses, and this price aviation matures, airports will need to bridge this could vary further when factoring in the potential gap, integrating infrastructure that can flexibly price premium of HVO. The price of electricity and support both gaseous and liquid hydrogen, and the initial purchase cost matter most for electric 9nsuring that investments made today are ready for buses. Hydrogen buses are particularly sensitive to tomorrow's multimodal hydrogen ecosystem. This how long they are used, because their upfront and s because industry and academia suggest that infrastructure costs are high. if the fleet is not sized iquid hydrogen may be more suitable for aircraff correctly or if there are limits on maintenance and propulsion in the future, though current ground refuelling flexibility, it becomes harder to keep operations rely predominantly on gaseous hydrogen costs down. This forward-looking scenario was also part of Other factors, such as the average speed of the the research for this paper. The main difference buses and the hours that the airport operates, also between the off-site hydrogen production scenario play a role by affecting how long the buses spend in (number 3 previously described) and the on-site motion, influencing the maintenance costs and the hydrogen production scenario is the infrastructure idle time for refuelling and charging. In Appendix 2 needed to adopt a hydrogen bus fleet within further considerations on the assumptions taken for the boundaries of an airport that has made a each of the technologies are analysed. complete transformation of its landscape, including capabilities for liquid hydrogen production, storage In summary, while energy prices, purchase costs and delivery. The capex required for on-site and how long the buses are used are the most hydrogen production and liquefaction is substantial, influential factors in all scenarios, it is government with estimates exceeding E450 million and annual subsidies and their influence on capex that would opex heavily influenced by electricity prices and directly affect upfront costs and whether these can iquefaction efficiency. Liquefaction remains the be offset over the lifetime of the assets. primary cost driver, and the TCO is highly sensitive to both the price of green hydrogen and the cost of The main exception to this analysis concerns the 9lectricity. Technological advances are expected to hydrogen bus scenario. Here, both the maturity of reduce both capex and opex by 2050, but the need hydrogen bus technology and the local availability for a “green premium* over conventional fuels would of hydrogen fuel can significantly influence persist in the near term. capex. Additionally, the cost and reliability of Decarbonizing Aviation Ground Operations: Altemative Bus Technologies 23

OCR:Importantly, mechanisms such as long-term As hydrogen airc raft are introduced, the interplay offfake agreements and targeled subsidies can between offsite hydrogen production for buses help manage the high initial costs and financial and onsite production for aviation could drive new risks associated with early-stage hydrogen valus chain concepts, particularly as logistical infrastructure. In addition, the availability of and handling challenges for liquid hydrogen renewable energy = especially a balanced mix of become more pronounced. In summary, airports wind and solar - can significantly lower hydrogen aiming to become regional hydrogen hubs must supply costs and reduce the need for oversized adopt a holistic, future-oriented approach - infrastructure. For airports in less favourable aligning investments in hydrogen and electricity locations, combining on-site hydrogen production infrastructure, anticipating the needs of both ground with imports via vessels or pipelines can further and air transport,1* and bullding in flexilbiity to optimize costs and improve resilience. adapt as technology and regulation evolve. This multistakeholder, systems-level perspective will be critical to achieving deep decarbonization and long- term operational resillience.

OCR:Conclusion Airportscanleadaviation'snet-zero transitionbyembracinginnovative, cost-effectivesolutionsforground operationsdecarbonization. The decarbonization of airport ground operations Hydrogen fuel cell buses, though currently facing stands as both an imperative and a strategic higher costs and infrastructure challenges, offer opportunity for the aviation sector. As this paper significant potential for future-proofing airport demonstrates, airports are uniquely positioned to operations - especially at larger hubs with drive meaningful emissions reduction by adopting demanding duty cycles and ambitions to serve low- and zero-emission technologies across their as regional energy hubs. As renewable hydrogen ground fleets. The comparative analysis of diesel, becomes more accessible and technology matures retrofitted electric, battery-electric and hydrogen fuel hydrogen buses may become a strategic choice for cell buses provides actionable insights for decision- airports seeking operational flexibility and alignment makers seeking to balance operational needs with broader energy transition goals. financial realities and sustainability ambitions. The successful transition to low-carbon ground Retrofitted electric buses emerge as a pragmatic. operations will require coordinated action across the cost-effective solution for the near term, enabling value chain. Airports must engage with airines, energy airports to leverage existing assets and achieve suppliers, infrastructure planners and policy-makers rapid emissions reduction with minimal operational to develop robust supply chains, invest in workforce disruption. This pathway is particularly attractive training and advocate for supporive policies for airports with newer diesel fleets or limited and incentives. Early adoption and pilot projects, capital, serving as a bridge fo full electrification particularly al regional airports, can create scalabie whille infrastructure and workforce capabilities models for larger hubs and for the wider industry. are developed. Ultimately, the choice of bus technology should Investing in new battery-electric bus fleets be guided by each airport's unique operational represents a forward-looking strategy, aligning context, financial capacity, regulatory support and with evolving regulatory requirements and long- strategic vision. By adopting a tailored, evidence- term sustainability objectives. While the initial based approach and leveraging multistakeholder investment is higher, ongoing operating costs are collaboration, airports can position themselves as significantly reduced, and the passenger and staff eaders in sustainable ground operations - delivering experience is enhanced through quieter, cleaner cleaner air, quieter environments and long-term operations. The economic case for electrification is value for passengers, staff and surrounding further strengthened by policy incentives and the communities. The transition to decarbonized ground maturing technology landscape, making this optior operations is not only an environmental imperative ncreasingly viable for airports with stable financial but also a strategic opportunity to future-proof resources and predictable operational profiles airport operations and contribute meaningfully to the aviation industry's net-zero roadmap. Decarbonizing Aviation Ground Operations: Altemative Bus Technologies 26

OCR:Appendix 1: Methodology The analysis presented in this paper is based on Tomorrow community validated the theoretical a comprehensive and multi-faceted approach, assumptions made during the research and provided incorporating various data collection methods to inputs to ensure both analyses were complementary. ensure a realistic perspective from the Airports of Tomorrow community. Throughout the exercise, over 20 in-depth interviews were conducted with experts drawn from across the The insights presented in this paper are based on airport ecosystem, ensuring coverage of all industry the following phases: profiles: airport operators, ground handling service providers,bus manufacturers,bus operators, An extensive desk research exercise conducted infrastructure developers and energy suppliers during Q1 2025, led by Judge Business School MBA students at Cambridge University, focused on The insights gathered from these different sources hydrogen buses as the main alternative technology were carefully analysed to offer a neutral and for benchmarking and comparison. The Airports objective view of the industry's challenges and risks. of Tomorrow community validated the different While most of the assumptions used in the TCO scenarios considered in this phase and the model were validated, some were simpliied and theoretical assumptions utized, through workshops may nol fully reflect the diversity of perspectives and bilateral calls. across the industry. As a result, the final figures should be seen as well-supported estimates that A second phase followed during Q2 2025, in which depend on certain conditions and are limited by graduate students from Imperial College London the scope of the interviews. Even so, this analysis explored battery-electric buses and retrofitted provides a useful tool to help airports make strategic diesel buses, with an emphasis on cost structures decisions about transitioning ground service infrastructure requirements and operational equipment as part of their decarbonization plans. suitabiity. As in the first phase, the Airports of Decarbonizing Aviation Ground Operations: Aitemetive Bus Technologies 26

OCR:Assumptions each scenario Table 1 in the paper presents the general charging infrastructure requirements and balttery assumptions that apply across all three replacement cycles. The TCO model created technologies, These include variables such as for this analysis is available on demand, and all average fleet size, range, utilization rate, expected sources are described in detail (including all average vehicle Bfespan and discount rate. Table 2 assumptions where sensitive data applies). This below summarizes technology-specific cost and model can be adapted for different regions and performance assumptions, such as refueling times operational contexts. TABLE 2 Baseline parameters by bus technology Baseline parameters Parameter Value Comment Average bus price (E/bus) 259,000 Based on an average of six different bus models Maintenance cost (E/km) 0.61 Average of three independlent sources Energy consumption (/km) 0.34 Based on an average of seven bus models sosnq jesea Diesel price (E/I) 1.67 Average retail price across 10 European countries Lifespan (yeers) 15 Various sources Salvage value (% of purchase price) 15 Driver training cost (E) 0 No additional training required Insurance cost (E) 0 Assumed to be self-insured Registration cost (E) 0 Assumed that no registration fees apply Government subsidy (% of purchase price) 0 No subsides for diesel buse6 Average bus price (E/bus)* 550,000 (electric) retrofitted bus, Average of five electric buse6 approximately 50% of new electric bus Capex learning rate (%/year) 3.9 Reduction expected as battery technology scales Maintenance cost (E/km)* 0.37/0.40 Electric/retrofitted, excluding battery costs Energy consumption (kWh/km) 1.15 Average of seven dlifferent buses Electricity price (E/kWh) 0.12 Valldated with stakeholders Battery replacement frequency (years) 9 Validated with stakeholders Battery replacement cost (% of new e-bus) 35 Based on multiple sources and stakeholder input Battery size (kWh) 386 Average of six different buses Bus-to-charger ratio 2:1 One charger for two buses; validated with stakeholders Bus output power (kW) 150 Two sockets per charger; one socket per bus Charger efficiency (%) 95 Typical market average; input power reduced to 143 kW Deoarbonizing Aviation Ground Operations: Aitemative Bus Technologie

OCR:Charging paftern (min-max%) 20-90 70% usable capacity to limit degradation Charger unit cost (E/kWh) 408.48 Based on various chargers in the market Charger hidden cost (% of unit cost) 60 Includes design, grid upgrades, site works Charging time (hours) 3.77 Based on input power, usable capacity and overnight charging Charger maintenance cost (E/unit/yeer) 2,300 Covers software updates and cooling maintenance DC charger warranty cost (E/unit/year) 736 Based on manufacturer warranty rates Charger salvage value (% of unit price) 25 Assumed similar to buses due to limited data pue Bus salvage value (% of unit price) 25 Higher resale potential due to battery value Lifespan (years)** 15 Based on various sources Driver training cost (E) 231 Based on electric bus requirements in Canada and the United Kingdom Insurance cost (E) 0 Assumed to be self-insured Registration cost (E) 0 Assumed that no registration fees apply Government subsidy (% of purchase price) 50 Covers half of the capex for both buses and charging infrastructure Average bus price (E/bus) 598,240 Average of six hydrogen buses Capex learming rate (%/year) 3.5 Reduction expected as hydrogen technology scaleG Bus maintenance cost (E/km) 0.42 Average of six different resources Bus fuel consumption (kgLH/km) 0.10 Average of four different bus models Hydrogen price (E/kg: grey, blue, green) 1.84, 1.89, 2.87 Average of sources. Projections of prices by 2030 Validated with stakeholders. nq Refueling time (minutes) 15 Based on market research Bus salvage value (% of unit price) 15% Resale potential due to asset value. Based on various sources Lifespan (years)** 15 Based on various sources Insurance cost (E) 0 Assumed to be self-insured Registration cost (E) 0 Assumed no registration fees apply Government subsidy (% of purchase price) 50 Covers half of the capex for both buses and charging infrastructure Deoarbonizing Aviation Ground Operations: Aitemative Bus Technologies28

OCR:Subsidies To complement the sensitivity analysis, this credits - and non-monetary incentives, including appendix provides a detailed table of subsidies toll exemptions, tax breaks and preferential access. and incentives available to support the adoption While comprehensive, the table is not exhaustive of zero-emission airport buses and associated and reflects the main programmes identified at infrastructure. The information is organized the time of writing. It is intended to give readers a by region and includes both direct financial consolidated view of the support schemes that can mechanisms - such as grants, rebates and tax significantly influence TCO across different markets. TABLE 3 Subsidies in the United States (US) Subsidy Jurisdiction Amount/percentage Coverage programme (country/state) Zero Emissions Federal Up to 50% of project cost Airport-owned, on-road zero-emission vehicles ZEVs, such Infrastructure Pilot Airport Vehicle and as buses and shuttles) and supporting charging infrastructure Programao for exclusive airport use Low or No Emission Federal Up to 85% for buses; Purchase or lease of low/zero-emission public transit buses, (Low-No) Grant up to 90% for faciity supporting facities and workforce development. Airport-only Program1 components services are ineligible. Commercial Clean Federal Up to $40,000 per vehicle Tax credit for businesses purchasing qualified commercial Vehicle Tax Credit clean vehicles with gross vehicle weight rating (GVWR) of (45W)22 14.000 pounds ormore Alternative Fuel Federal 6% of cost, up to $100,000 per un Tax credit for businesses installing charging infrastructure Infrastructure Tax Credit (30C)²a EnergllZE Commercial Callonia Varies; targeted funding EV charging and hydrogen refueling infrastructure for Vehicles Project24 lane6 medium- and heavy-duty frucks, buses and equipment Texas Volkswagen TexaS Up to 100% of Replacement of older diesel vehicles with all-electric models, Environmental incremental cost for including shuttle/transit buses and airport ground support Mitigation Program government entities; 75% equipment, plus supporting infrastructure (TxVEMP)-All-Electric for non-government Grant2s ComEd Business Illinois (ComEd Up lo$120,000for Rebates for the purchase or lease of new or pre-owned fleet and Public Sector EV Service Area) a fransit bus; up to EVs, including transit buses Rebatess $180,000 for select customers ComEd Make-Ready Illinois (ComEd Up to $8,000 per level-2 Rebates for electricalinfrastructure upgradles required to Program2 Service Area) (L2) charger port; up to $1.000/kW for direct- install EV chargers for non-residential customers current fast chargers (DCFC) Georgia Power EV Georgia (GA Power $250/kWfor L2 chargers; Rebates for purchase and installation of commercial EV Charger Plus Rebatea Service Aree) $150/kWforDCFC Maximum $30,000 per chargers project Charge Ahead Colorado Up to 80% of charger Grants for Level 2 and direct current (DC) fast-charging Colorado" cost (maximum$70.000 stations for public entities, businesses and multifamily housing for dual-port DCFC) Fleet-ZERO Grant Coorado Up to $500,000 per Funding for EV charging infrastructure to suppor light- Program* award medlum- and heavy-duty tleet vehicles Decarbonizing Aviation Ground Operations: Altermative Bus Technologie 29

OCR:TABLE 4|Subsidies in Canada Subsidy Jurisdiction (country/province) Amount/percentage Coverage programme Fund (ZETF)-capital Zero Emission Transit Federal Up to 50% of eligible Procurement of zero-emission buses (ZEBs) charging costs;max CAD350 refuelling infrastructure and facity upgrades projectsa1 million per project Fund (ZETF)-planning Zero Emission Transit Federal Up to 80% of eligible Feasibility studlis, modelling, lifecycle analysis and costs comprehensive electrification planning projects Incentives for medium- Federal Up to CAD200.000 per coach bus;tiered by Point-of-sale rebate on the purchase or leese of eligible new and heavy-duty ZEVs vehicle class medium- and heavy-duty ZEVs (iMHZEV) CleanBC Go Electric British Columbia Up to CAD50,000 for Rebates for various ZEVs, including a dedicated category for Rebatesa airport specialty vehicles airport and port specialty vehicles (manufacturer suggested retail price, MSRP) >$300,000) BC Hydro EV Fleet British Columbia Up to100%of Funding for fleet electrification planning and electrical Programc infrastructure costs for infrastructure installation to support EV charging public entities Ecobus Incentive Quebec CAD240,000 per electric Subsidy for the purchase of an electric school bus Program school bus Electric Vehicle Alberta Up to 46% of charger Charging Program Rebates for the purchase and installation of EV chargers for installation costs (max CAD75,000 per DCFC) municipalties, businesses and other organizations (EVCP)as TABLE5 Subsidies in Europe Subsidy Jurisdiction Amount/percentage Coverage programme Zero Emission Bus United Kingdom Up to 75% of cost Purchase of new ZEBs (single and double deck) and Regional Areas (England) dlifference between ZEB (ZEBRA) Schemea and diesel bus: up to associated charging/refuelling infrastructure 75% of infrastructure cost Bus Service Operator United Kingdom E0.22 per km operated Operational subsidy for certified ZEBs running on Grant (BSOG) ZEB (England) public routes. This may not cover airside operations but may Incentive" apply to routes to/from airports Federal Funding Call Germany Up to 80% of additional Purchase of baftery-electric and fuel cell buses, retrofits and for Alternative Drives in vehicle cost; up to 40% charging/refuelling/maintenance infrastructure Buses of infrastructure cost. Maximum 15 milion per project Bus Funding Germany (Bavaria) Up to 105,000 per State-level subsidies for the purchase of climate buses Programme articulated (longer electric, hydrogen, biogas) and depot electrification (Example)* than usual e-bus, plus Iinfrastructure grants Advenir Programme1 France 960-2,200 per Support for installation of charging stations for charging point commercial vehicles MOVES III Spain Up to 70% of charging Grants for purchase of EVs and installation of charging Programmef2 infrastructure cost infrastructure, plus tax benefits (maximum 2.5 million for companies);: up to 7,000 for passenger cars Alternative Fuels European Union Varies by project EU-level funding for alfernative fuels infrastructure, including Infrastructure Facility (EU) electrification of ground handing services at major airports (AFIF)*a Deoarbonizing Aviation Ground Operations: Altemetive Bus Technologies 30