www.advent.energy PresentationSeptember 2021 NEXT-GENERATION HT-PEM FUEL CELL TECHNOLOGY“ANY FUEL. ANYWHERE.”

DISCLAIMER The information, opinions, estimates, projections, forecasts, targets, or prospects contained in this presentation are provided as at the date of this presentation and are subject to change without notice.This presentation contains financial information prepared in accordance with U.S. generally accepting accounting principles (“GAAP”) that have been extracted without material adjustment from audited GAAP financial statements and/or extracted or derived from unaudited accounting records that have been used to prepare GAAP financial statements. This presentation also contains certain non-GAAP financial measures which have not been and will not be audited. These non-GAAP financial measures are not recognized measures of financial performance or liquidity under GAAP, but are measures used by the management of Advent Technology Holdings, Inc. (“Advent”) to monitor the underlying performance of Advent’s business and operations. These non-GAAP measures may not be indicative of Advent’s historical operating results nor are such measures meant to be predicative of future results. These measures and ratios may not be comparable to those used by other companies under the same or similar names. As such, undue reliance should not be placed on these non-GAAP financial measures. Advent is not able to provide a reconciliation of the Company’s non-GAAP financial guidance to the corresponding GAAP measures without unreasonable effort because of the inherent difficulty in forecasting and quantifying certain amounts necessary for such a reconciliation. Certain financial information contained herein is unaudited and is based on internal records and/or estimates. This presentation contains certain forward-looking information which may not be included in future public filings or investor guidance. The inclusion of financial information or metrics in this presentation should not be construed as a commitment by Advent to provide guidance on such information in the future. The information contained in this presentation is the property of Advent. This presentation may not be copied, published, reproduced, or distributed, in whole or in part, at any time without the prior written consent of Advent. The trademarks and trademark symbols used herein are the properties of their respective owners.This presentation contains financial forecasts with respect to Advent’s estimated future performance. Advent’s independent auditors have not audited, reviewed, compiled, or performed any procedures with respect to the projections for the purpose of their inclusion in this presentation and, accordingly, have not expressed an opinion or provided any other form of assurance with respect thereto for the purpose of this presentation. These projections should not be relied upon as being necessarily indicative of future results. In this presentation, certain of the above-mentioned projected financial information has been included (in each case, with an indication that the information is an estimate and is subject to the qualifications presented herein) for purposes of providing comparisons with historical data. The assumptions and estimates underlying the prospective financial information are inherently uncertain and are subject to a wide variety of significant business, economic, and competitive risks and uncertainties that could cause actual results to differ materially from those contained in the prospective financial information. Accordingly, there can be no assurance that the prospective results are indicative of the future performance of Advent or that actual results will not differ materially from those presented in the prospective financial information. Inclusion of the prospective financial information in this presentation should not be regarded as a representation by any person that the results contained in the prospective financial information will be achieved. The financial forecasts reflect assumptions that are subject to change, and there can be no assurance that Advent’s financial condition or results of operations will be consistent with those set forth in such analyses and forecasts. 2

DISCLAIMER (continued) This presentation contains “forward-looking statements” within the meaning of applicable securities laws, including statements with respect to Advent’s strategies, future opportunities and growth prospects, Advent’s financial statements, as well as other information and statements that are not historical fact. These forward-looking statements regarding future events and the future results of Advent are based on current expectations, estimates, forecasts, and projections about the industry in which Advent operates, as well as the beliefs and assumptions of Advent’s management. These forward-looking statements are only predictions and are subject to known and unknown risks, uncertainties, assumptions, and other factors beyond Advent’s control that are difficult to predict because they relate to events and depend on circumstances that will occur in the future. They are neither statements of historical fact nor promises or guarantees of future performance. Therefore, Advent’s actual results may differ materially and adversely from those expressed or implied in any forward-looking statements and Advent therefore cautions against relying on any of these forward-looking statements. Factors that might cause or contribute to such differences include, but are not limited to: economic conditions globally; the impact of competition; political and economic developments in the countries in which Advent operates; regulatory developments in the U.S., Greece, Europe, and internationally; the COVID-19 pandemic; Advent’s ability to manage growth; Advent’s ability to execute its business plans and the timing and costs of these plans; Advent’s estimates of the size of the markets it serves; the rate and degree of market acceptance of Advent’s products; rising costs or pricing pressures adversely affecting Advent’s profitability, including sales and marketing expenses; expectations regarding capacity constraints; potential litigation involving Advent; the validity or enforceability of Advent’s intellectual property and Advent’s compliance with the intellectual property rights of third parties; and other risks and uncertainties indicated from time to time in Advent’s filings with the U.S. Securities and Exchange Commission (“SEC”), including those set forth under “Risk Factors” therein, and other documents to be filed with the SEC. Any forward-looking statements made by or on behalf of Advent speak only as of the date they are made. Advent undertakes no obligation to update any forward-looking statements to reflect any changes in their respective expectations with regard thereto or any changes in events, conditions, or circumstances on which any such statement is based. Accordingly, attendees and recipients should not place undue reliance on forward-looking statements due to their inherent uncertainty. In this presentation, Advent relies on and refers to information and statistics regarding industry data. Advent obtained this information and statistics from third-party sources, including reports by financial data firms and other firms. Advent has supplemented this information where necessary with its own internal estimates, taking into account publicly available information about other industry participants and Advent’s management’s best view as to information that is not publicly available. Such information has not been subject to any independent audit or review. To the extent available, the industry, market, and competitive position data contained herein has come from official or third-party sources. Third-party industry publications, studies, and surveys generally state that the data contained therein has been obtained from sources believed to be reliable, but that there is no guarantee of the accuracy or completeness of such data. While Advent reasonably believes that each of these publications, studies, and surveys has been prepared by a reputable party, neither Advent nor any of their respective directors, officers, employees, agents, affiliates, advisors or agents have independently verified the data contained therein. In addition, certain industry, market, and competitive position data contained herein come from Advent’s internal research and estimates based on the knowledge and experience of Advent’s management in the markets in which Advent operates. While Advent reasonably believes that such research and estimates are reasonable, they, and their underlying methodology and assumptions, have not been verified by any independent source for accuracy or completeness and are subject to change. Accordingly, reliance should not be placed on any of the industry, market, or competitive position data contained in such information and no representation or warranty (express or implied) is given that such data is correct or complete. 3

ABOUT ADVENT TECHNOLOGIES HOLDINGS, INC. 4 Next-generation HT-PEM FUEL CELL Technology Thousands of systems sold to Defense, Off-Grid, Remote Power Markets in recent yearsOpportunity for Heavy-Duty Automotive, Aviation, Marine MARKET-READY (Total Addressable Market: $72+ billion by 2030) Public listing (NASDAQ: ADN) entry in February 2021$116 million of cash on the balance sheet (June 2021). No debt STRONG BALANCE SHEET 190 patents issued, licensed, or pendingStrategic Partner of the U.S. Department of Energy (DoE). Joint development with Los Alamos National Lab, Brookhaven National Laboratory, National Renewable Energy Laboratory exclusive award of the L’Innovator Program Decarbonization is a key priority by governments and industries across the globeThe U.S. is working towards a 50-52% reduction from 2005 levels in economy-wide net greenhouse gas pollution in 2030. The EU Hydrogen Strategy aims for 6GW of renewable hydrogen electrolyzers in the EU by 2024 and 40GW by 2030. GLOBAL MANDATE TO DECARBONIZE Strong pipeline. Manufacturing in the U.S., Denmark & GermanyTarget revenues of $250+ million by 2025Target Gross Margins of 30% HIGH-GROWTH PROFILE

20+ years as a C-Suite Officer in Tech/Marketing (founded start-up to AIM & Nasdaq IPOs)B.S. in Electrical Engineering and B.A. in Business Economics, Brown UniversityPh.D. in Supply Chain Management and M.Sc. in Manufacturing Engineering, Boston University Chris KaskavelisCMO Experienced Leadership Team 5 Proven track record of technological development and commercialization Vasilis Gregoriou*Chairman & CEO 35+ years of technology commercialization 25+ years in fuel cellsVolume manufacturing expertDoE Manufacturing AwardBASF Fuel Cell Inc.PEMEAS Inc., and De Nora N.A.E-TEKB.S. in Chemistry, Duke UniversityPh.D. in Chemistry, University of Cincinnati Emory De Castro*CTO 25 years of finance experienceMyers IndustriesIngersoll-RandChiquita Brands InternationalAmerican Institute of Certified Public AccountantsB.S. Accounting & Finance, Miami University *Indicates member of Board of Directors following the Business Combination. Additional Board of Director members include Katherine Fleming, Anggelos Skutaris, Katrina Fritz and Lawrence Clark. 30+ years experience in corporate and securities law, M&A, VC, corporate finance and IP lawLong track record working with companies in the clean energy and technology sectors, with specific experience in the fuel cell industryB.A., Providence CollegeJ.D., New England School of LawLL.M. in Corporate Law, New York University Jim CoffeyGeneral Counsel & COO 30+ years of operational and strategy experience in the U.S. and EuropeWorld-renowned renewable energy expertExtensive experience in product development and company managementMBA, Northeastern UniversityPh.D. in Physical Chemistry, Duke Kevin BrackmanCFO

ADVENT FUEL CELL TECHNOLOGY: “ANY FUEL. ANYWHERE.” 6 Advent Fuel Cell Stack Advent MEA Defense Off-Grid Heavy-Duty Automotive Aviation Marine Combined Heat & Power ANY FUEL Fuel for most heavy-duty mobility & industrial markets HYDROGEN Option for off-grid & portableInterim low-cost option for mobility Low-cost hydrogen at minimal infrastructure coste-Methanol, DME, LOHC METHANOL MARKET IN NEAR FUTURE MARKET NOW e-FUELS (H2 carriers) ANYWHERE COLD HEAT HUMIDITY POLLUTION MARKETS ELECTRICITY

ADVENT HT-PEM: WHAT DOES IT MEAN FOR... 7 TECHNOLOGYIt can handle almost any low-carbon or zero-carbon fuel. Competitor LT-PEM fuel cells need pure hydrogen, which requires a large amount of spending on infrastructure.Enables more efficient heat management (vs. LT-PEM), which is needed for aviation and heavy-duty automotive.Can withstand extreme temperatures, pollution and humidity, leading to a longer lifetime and lower total cost of ownership (TCO) (vs. LT-PEM). Advent develops and holds the IP on the core technology (MEA materials). BUSINESSShips, Planes, Defense and Trucks expected to use e-Fuels.Immediate market now with low-carbon methanol.India, China and emerging markets need solutions with minimal infrastructure costs. Advent Advantage PROJECTED FUELS CONSUMED IN THE TRANSPORT SECTOR IN 2050 Actively developed with world-leaders in research innovation: NREL, LOS ALAMOS, BROOKHAVEN and U.S. DEPARTMENT OF ENERGY.

OFF-GRID & PORTABLE POWER IS AN IMMEDIATE MARKET TO EXPLORE AND GROW 8 FUEL CELL: Off-Grid, Portable 15 kW 4+hrs days weeks Autonomy Advent 2025 ENERGY: Methanol, e-Fuels, & other liquid fuels are easy to transport and are an attractive solution for the off-grid and portable market Power 50 W 5 kW 250 W Telecom Backup Power 1m+ off-grid towers,attractive for Asia, Africa, instead of diesel generators Defense Portable Power 3x-25x weight advantage vs. batteries Methane Reduction Critical infrastructure remote power. Impact: equivalent to 8M cars’ annual CO2 via adoption at North American wellheads alone Surveillance Security long autonomy, quiet, lightweight Diesel generator replacementLow Power, Long AutonomyBatteries are not a desirable solution due to their size, weight, and need to rechargeLiquid hydrogen-bearing fuels are a more efficient option

MARKET & COMPETITIVE LANDSCAPE: ADVENT POSITIONING 9 BATTERY EV OFF-GRID & PORTABLE TRUCKS, BUSES AVIATION 100 kWh MWh MWh-GWh 4hrs 8hrs 12+hrs days Autonomy P2X, CHP & MARINE HEAVY-DUTY MOBILITY ENERGY: GRID POWER H2 (PURE) H2 (PURE, REFORMED, LOHC), METHANOL, E-FUELS, NATURAL GAS) Path to mobility market through JVs & Joint Development Agreements COMPETITION: LI-ION LOW-TEMPERATURE PEM SOFC/MCFC Increasing interest for large-scale systems

ADVENT EXECUTES ON BUSINESS PLAN POST NASDAQ ENTRY Development /Evolution Key Partnerships Market Penetration Advent has approximately 190 patents issued, licensed, or pending and has accessed its own and the 3rd party global HT-PEM investment of partners to create the leading next-generation fuel cell technology provider. 170+Employees Patras and Athens, Greece 38 Successful R&D Programs 190 Patents Issued, Licensed, or Pending 700+Combined Technical Years of Experience 1960s 2006 2013 2018 2019 2021 2021 Q1 First LT-PEM fuel cells AdventHT-PEMGen 1 Advent-BASFHT-PEMGen 2 DoE selects Advent forL’Innovator Joint Dev. Program SAFRAN &ESS expand programcontracts Advent enters NASDAQ (“ADN”) Raises $158 million UltraCellAcquisition New Boston & Europeproduction facilities under construction UltraCell expands DoD contract HT-PEM Gen 3 launchwith LANL Mobilitynext-genFuel Cell under development 2021 Q2 R&D withNASA, ESA, DoE 2012 Acquisition Serenergy A/S (Denmark) and fischer eco solutions GmbH (Germany) *This number includes part-time employees and contractors. San Francisco Bay Area, USA Boston and Charlestown, MA, USA Aalborg, Denmark Achern, Germany 2021 Q3 DoE ESA NASA BASF LOS ALAMOS BROOKHAVEN NREL ESS SAFRAN NASDAQ 10

APPLICATIONS

12 SerEnergy has deployed hundreds of systems to telecom tower operators around the worldRemote monitoring and self-maintaining systemsOperate at extreme conditions Fuel cells do not produce particulate pollutants or unburned hydrocarbons. They emit less carbon dioxide than other, less efficient technologies. With the use of e-Fuels, this creates a path to effectively zero-emissions energy. 92 additional highly-skilled R&D, manufacturing and sales professionalsHT-PEM focused with proven production capabilities in Denmark & GermanyAcceleration with business in Asia and Northern Europe markets OFF-GRID POWER: TELECOM TOWER POWER METHANOL FUEL CELL SYSTEMS (5-15kW) CLEAN ENERGY 03 DEPLOYABLE 02 PROVEN 01 Acquisition of SerEnergy & fischer eco solutions fuel cell businesses closed on September 1, 2021 Power generation in off/bad-grid sites for critical infrastructure, telecom, construction sitesSelf-contained cabinet systems with 1-3 5kW fuel cells Business Case:Smart Communications deploys SerEnergy fuel cells across its Philippine telco network

13 Uses MethanolFuel cells will use industrial-grade methanol already available at the site10x less greenhouse gas emitted vs. traditional combustion generatorsZero nitrogen oxides, sulfur oxides and particulate emissions OFF-GRID POWER FOR CRITICAL INFRASTRUCTURE: U.S. AND CANADA O&G OPPORTUNITIES PROVEN 04 ANY FUEL 01 Executed agreements to trial 10 50W systems in Alberta with oil & gas majorsInitial deployment in Canada anticipated in Q3 2021 Projection: Mass deployment by 2023 ANYWHERE 02 Rugged and ReliableUnlike renewables, fuel cells work in almost any climate, geography and weather conditionDesigned to meet critical power requirements without interruptionDoes not fail in extreme conditions, can operate at low temperatures down to at least -200CFuel Cells can deliver power to well sites 24/7/365 Reduce O&G well site methane emissions (up to 40 Mt CO2e per year)Fuel cells powering 185,000 oil and gas wellheads in Canada and the U.S. will reduce methane emissions (up to 40 million tons of CO2e per year), which is equivalent to the carbon footprint of more than 8 million passenger carsThe implementation of the solution can contribute to rapid decarbonization of the Oil & Gas industry by mitigating the methane emissions problem. GOAL: METHANE EMISSIONS TO ZERO 03 SHELLREPSOLHUSKYCENOVUS ENERGYNAL RESOURCESBELLATRIXMODERN RESOURCESCALSCAN SOLUTIONS

14 Portable Power: Military grade, 55W-1kW batteryUSA made and DoD deployed portable fuel cellOperates at -200C-+550C Can use methanol (contained in some windshield washer fluid) as fuelTransported at a much lower cost than single-source fuel, for example, hydrogenMajor advantage from logistics/ operations perspectiveBased on Advent’s “Any Fuel” MEA SecuritySurveillanceEmergency ResponseUAVsRecreation DEFENSE INDUSTRY: WEARABLE FUEL CELL FOR OFF-GRID POWER MOBILITY 03 PORTABLE 02 PROVEN 01 NEXT MARKETS 3 Gallons of Methanol(approximately 20 lbs) 121 lbs of batteries VS 3x-25x lower weight compared to batteries

LARGE-SCALE SYSTEMS: INDUSTRIAL (P2X & CHP MARKETS) 15 MW-level Systems Power to Hydrogen: to balance grid by producing heat & power from stored hydrogenDatacenters: reliable, high-quality powerOff-Grid Power: For large-scale off-grid power needsMining Industry: Vehicle recharging and remote power needs GREEN SOLUTION 03 Facilitate path to zero-emissions for large-scale and grid level systems FUEL-FLEXIBLE 01 Supports methanol or natural gas and hydrogen if/when available. OFF-GRID 02 No grid, no hydrogen network, makes HT-PEM attractive solution LARGE-SCALE 04 MW specific product design for low-cost of manufacturing and long lifetime 1 MW FUEL CELL SYSTEM BY ADVENT

COMBINED HEAT & POWER: UNITS FOR HOME AND COMMERCIAL APPLICATIONS 16 Commercial Suitable for small-scale commercial buildings, Businesses and more:RestaurantsHotelsOffice buildingsWorkshopsStoresMedical CentersBanks Private Suitable for different types of buildingsSingle-family homesMulti-family homes HiPo Station 3-5kW MODULAR 03 Can scale up to bigger units by adding systems in parallel FUEL-FLEXIBLE 01 Can start deployment in natural gas network and eventually support H2 input or other fuels without new investment THE RIGHT TEMPERATURE 02 LT-PEM doesn’t provide quality heat, and Solid Oxide Fuel Cell (SOFC) is too hot (600+oC) COST 04 Lower cost to manufacture than SOFC, simpler supply chain APPLICATION Electrical power and heat for family homes, companies, public and commercial buildings OPERATING MODE All year (~8,700hrs) MONITORING Available via web enabled device FUEL Hydrogen, Natural gas, LPG, Methanol, e-fuels and any hydrogen carriers FUEL CELL TYPE HT PEM Fuel Cell (3-5kW) OVERALL EFFICIENCY 90% ELECTRICAL EFFICIENCY 40% THERMAL POWER Up to 5kW ELECTRICAL ENERGY GENERATED/YEAR 26,000kWhr THERMAL ENERGY GENERATED/YEAR 44,000kWhr WEIGHT 490kg HEIGHT X WIDTH X DEPTH 1,520mm x 860mm x 610mm SERVICE 12 months (air filter, water purification) Advent Technologies has been nominated by the Greek Ministry of Development and Investment to be part of the first wave of Important Projects of Common European Interest (“IPCEI”) on Hydrogen. Advent will also be spearheading the Green HiPo project as part of the overall, joint “White Dragon” project.

White Dragon (Decarbonization & Solar Power to Gas Project) Duration 2022-2029 (first phase) Green H2 production Power2Gas: 250,000 tons / year Green H2 for other uses: 58,000 to 71,000 tons / year White Dragon is the flagship decarbonization project for Greece and one of the top-10 projects by size across Europe for green hydrogen production and storage (Power to Gas). Developed by a consortium of Greek companies for development between 2022 and 2029, it consists of: GW-scale variable renewable energy/electricityHydrogen production & storage (electrolyzers used for green h2 production, and high-temperature fuel cells for energy storage, electricity grid stabilization, and district heating locally) Hydrogen and natural gas blending for pipeline transportation Green HiPo White Dragon Green HiPo Advent Technologies Projects White Dragon & Green HiPo (4.65GW Green Hydrogen & 400MW Fuel Cells), approved by Greek Government and submitted to the European Union Advent’s two Greek Important Projects of Common European Interest (“IPCEI”) have been approved by a joint decision by the Greek Minister of Development and Investments, Mr. Adonis Georgiadis, and the Greek Minister of Environment, Energy, and Climate Change, Mr. Kostas Skrekas, and now await EU approval. COMBINED HEAT & POWER: WHITE DRAGON 17

GREEN HiPo Duration 2022-2029 (first phase) Project Scope: Manufacturing of Fuel Cells & ElectrolyzersNorthern Greece to support White Dragon project Size Fuel Cell Capacity: 400MWElectrolyzer Capacity: 4.65 GW(to be installed by Advent in the 7-year timeframe) Advent Technologies Projects Green HiPo approved by Greek Government and submitted to the European Union to establish manufacturing capacity for 4.65GW Green Hydrogen Electrolyzers & 400MW Fuel Cells Why Advent’s Fuel Cells Advent’s HT-PEM fuel cells are well-suited for heat and power applications: They operate at the 160-2000C range and can produce quality heat, in addition to electricity. Combined efficiency of fuel cells to 85 percent. They operate with natural gas, a natural gas-hydrogen blend, and eventually with green hydrogen. The Green HiPo project concerns the development, design, and manufacturing of HT-PEM fuel cells for the production of heat and power. It is a complementary project to White Dragon and will produce the fuel cells that will power White Dragon’s green energy plan.The project will contribute to the economic development of the region by providing approximately 1,400 jobs in innovative sustainable technology. The facility will initially manufacture fuel cells of 15kW/units, gradually reaching 120kW, and then 1MW scale single units before finally becoming a multi-MW platform. COMBINED HEAT & POWER: GREEN HiPo 18

30kW stacks used to create 120, 240kW etc. power options Operate at high-temperatures, (80-240oC) Based on proprietary materialsNo need for water management H2, H2 (LOHC) & e-Fuels(methanol, natural gas) SIMPLE REFORMER Smaller lithium ion batterySolves the limitations of pure EV trucksOption to refuel with liquid fuelsSmall Radiators HEAVY-DUTY TRUCKS: ADVENT’S “ANY FUEL. ANYWHERE.” TECHNOLOGY Simpler to design and manufacture “Any Fuel. Anywhere.” reduces TCO (vs. LT-PEM) ADVENT HT-PEM MEAs ADVENT FUEL CELL Operates at “optimal” temperature and high voltageReduces system complexity (balance of plant) On-board hydrogen generation FUEL FLEXIBILITY 01 COST 02 LONG RANGE & FAST RECHARGE 03 EFFICIENCY 04 19

IP STRATEGY 20 High temperature Is key for flight efficiency Compared with Batteries, e-Fuels or even H2, provide an attractive solutionPAYLOAD increases 2x+RANGE increases from minutes to hoursBased on: Next-generation HT-PEM MEAsProprietary ultra-lightweight non-metal plates Refills in minutes vs. hours Projected trip from San Francisco to Palo Alto* Advent Fuel Cell 4 Trips Refill 1 – 2 times a day Wait to recharge before second trip 3 Hours H2 or dimethyl ether (DME) is an attractive fuel sourceARPA-E: minimum of 2,000Wh/kg energy density is required for flightJet fuel: 12,000Wh/kg, H2: 40,000Wh/kg,Methanol: 5,472Wh/kg, DME: 7,889Wh/kgBattery: 260Wh/kg AVIATION: COMMERCIAL FLIGHTS, DRONES, eVTOLs Surveillance DronesDelivery DroneseVTOLsAirplanes MARKETS RANGE / PAYLOAD 01 Case EFFICIENCY 02 UTILIZATION 03 MULTI-FUEL 04 Passengers Recharge 2 Battery 3 1 eVTOL 10Mins *Expected performance of a typical trip from San Francisco to Palo Alto in California of an eVTOL using the Advent Fuel Cell vs. using just a battery.

H2, H2(LOHC) & Methanol, natural gas Unlike a battery that needs charging, fuel cells run as long as there is hydrogen fuel. Thus, longer routes and larger vessels may be possible Batteries can work together with fuel cells (hybrid architectures of battery and fuel cell) FUEL FLEXIBILITY 01 MODULAR POWER SYSTEM 02 LONG RANGE & FAST REFILL 03 NO EMISSIONS 05 MARINE APPLICATIONS: ADVENT’S “ANY FUEL. ANYWHERE.” TECHNOLOGY Fuel cell ship Vessels can freely access emission control zones hybrid architecture 04 Fuel Cell System Fuel Storage 30kW stacks used to create 120, 240kW etc. power options for auxiliary power and passenger accommodations Operate at high-temperatures, (80-240oC) Based on proprietary chemistryNo need for water management ADVENT HT-PEM MEAs ADVENT FUEL CELL 1MW Stacks used to create multi-MW for propulsion Scalable for many load requirements and applications (e.g. propulsion system, auxiliary power) Methanol is used by a Reformer to create Hydrogen and Air which enters the Fuel Cell and is converted to Electricity. 21

TECHNOLOGY

ADVENT THE PATH TO LOW-COST FUEL CELL SYSTEMS 23 MATERIALS INNOVATIONNew MEA with U.S. Department of Energy (DoE)Power Density 1w/cm2Maximum LifetimeRoll-to-roll material fabrication SCALEHigh-volume manufacturing Germany ENGINEERINGINNOVATION:Next-generation Digitronics Design STANDARDIZATIONReformer changes from H2 to Methanol to Natural Gas to Zero Carbon e-FuelsSame Stack & MEALow TCO with fuel flexibility END PRODUCTSAlready shipping products in off-grid, defense & portable power marketStrategic Partnerships for end-products in mobility REDUCE TCO: $/kWH Increasing lifetimeReducing materials & production cost/kWPlatinum (Pt) recycling/ financingFuel-flexibility: fuel cost & infrastructure, immediate market XX55TM 5kW module HT3-5000 Outdoor cabinet2 X HT3-5000 fuel tank TELECOM DEFENSE HEAVY-DUTY TRUCKS

24 The MEA is the “heart” of the Fuel Cell and it defines: What fuels can be used, efficiency, power densityThe design parameters for the rest of the components, including the balance of plant The Total Cost of Ownership of the fuel cell system Product Development Plan MEA Cost Targets $80/kW at mass scaleRoll to Roll ManufacturingUltra-low Platinum technology 1 4 6 7 1. Lightweight Composite End Plate2. Current Collector3. High Performance Bipolar Plate (BIP) With Integral Thermal Management4. Anode Gas Diffusion Electrode (GDE)5. High Temperature Polymer Electrolyte Membrane (HT-PEM)6. Cathode Gas Diffusion Electrode7. Assembled HT-PEM Membrane Electrode Assembly (MEA) Fuel Cell Stack Components Develop & Scale-up MEA Production in-house (U.S.-based)Partner/license production of other components ADVENT INSIDE THE FUEL CELL STACK: MEA & MORE 5 2 3

25 Competitive Advantage Next-Generation Technology: LT-PEM developed in 1960s has reached its limits (75oC operation) New Chemistry: LT-PEM is water-based while HT-PEM relies on a conductive plastic resilient to extreme temperatures. No water management allows for a simpler design, longer lifetime and smaller balance of plant Great Potential: Beginning of lifecycle product with room for substantial further improvement Target Product Roadmap Long lasting Degradation is still a problem for fuel cellsAdvent triples lifetime (~10,000 vs. 3,500 hrs @ 10% power loss) Fuel-Flexible H2 infrastructure installs fast with methanol or H2 sources like biogasImpurities in regular hydrogen such as 10 ppm CO damage LT-PEMOur materials withstand > 2 % CO (4% at 200C)HT-PEM function despite air pollution conditions, unlike LT-PEM Resilient Environmental flexibility increases life and reduces costAdvent units work anywhere in the worldLT-PEM does not run well hot or dry: < 50% RH and >30 °C ambient.Our technology runs from 0% RH (Nevada) to 100% (Florida)Advent runs -30 °C to +55 °C ambient temperature at FULL POWER Sustained High Power Similar to current tech (1,100 mW/cm2 peak power) without the extra weight and volume of complex cooling and water management Cost Advantage Roll-to-roll processing for automation integration Mated to catalyst technology that reduces platinum 8-10 foldSimpler system design and fuel flexibility drop TCO substantially Technical Specs HT-PEM to LT-PEM Comparison Actively developed with world-leaders in research: NREL, LOS ALAMOS,BROOKHAVEN and U.S. DEPARTMENT OF ENERGY ADVENT HT-PEM MEA TECHNOLOGY IS A GAME CHANGER 2021 PrototypeMEA 2022 OptimizedMEA 2023 PilotProduction 2024 MassProduction

ADVENT FUEL CELL STACK: NEXT-GENERATION TECHNOLOGY 26 Competitive Advantage Multifuel capability: H2, H2(LOHC), Methanol, e-Fuels, DME, Natural Gas Lifetime: Micro-fuel cell architecture contributes to a long lifetime, max MTBF Efficiency: High-Voltage Operation for maximum efficiency Resilient: To extreme heat, cold, humidity, pollution, H2 impurities 30kW HT-PEM Stack Module (Twin 15kW) Technical Specs targets of next-generation stack Weight: <26kg 15kW ModulesStack Efficiency: 54% Dimensions: 55*55*8 cm (L*W*H) “skateboard” designLifetime: 10K-40K hours (depending on application)Operating Temperature: 80oC to 240oC Startup Time: <180 secs Ambient Temperature: -38oC to 58oC Operating Voltage: 300V modules (15kW) Connect modules in series or parallelStart/Stop: 8,000 cycles (12 years) Consumption H2: 13.49kWh/kg “ e-Fuel/methanol: 2.01kWh/kg Cooling Technology: Heat-pipes (truck) Hydro-formed microchannel (flight)Options: Built-in fuel reformer Target Product Roadmap Cost Targets System: $250/kW at mass scaleOperating Cost: < $0.15/kWh assuming $2/kg H2 High reliability, high voltage stacks 2021 PrototypeStack 2022 OptimizedStack 2023 PilotProduction 2024 MassProduction

BUSINESS MODEL

REVENUE BREAKDOWN* 50%SYSTEMSOff-GridTelco TowersDefenseRemote Power 20%MEAs 15%ENGINEERING & License Fees 15% GRANTS Support Engineering & System cost/kW directly *Projected 28

29 CORE IP +TECHNOLOGY TIER 1 AND OEM(Target Partners) HT-PEM: ALL MARKETS LT-PEM: BUSES, TRUCKS SOFCCHP, INDUSTRIAL BUSINESS MODEL: ADVENT INSIDE CORE IP + TECHNOLOGY BALLARD POWERCELL CERES POWER BLOOM ENERGY AUTOMOTIVE NISSANGENERAL MOTORSVOLKSWAGEN VOLVOMERCEDES-BENZTOYOTAMANJOHN DEERECUMMINSCATERPILLARNIKOLA HEAVY-DUTY OIL & GAS EXXONMOBILBAKER HUGHESBP AVIATION AIRBUSSAFRANBOEING LOCKHEED MARTINTHALESRAYTHEON TECHNOLOGIESNORTHROP GRUMMANGENERAL DYNAMICS DEFENSE COMBINED HEAT & POWER DOOSANPANASONIC POWER GENERATION BOSCHMITSUBISHIGENERAL ELECTRIC AND MORE…

Engineering Fees Prototype Phase:Advent develops specific prototype fuel cell system for application/market Year 3: 30 MW Year 5:450 MW Year 4: 120 MW Year 6: 750 MW 30 Early Production Phase:Advent manufactures MEAs and licenses out fuel cell technology to Tier 1/OEM Mass ProductionBoth Parties scale up their production MEA sales Licensing fees 2. Tier 1/OEM:System manufacturing scale up and commercial expansion 1. Advent:Manufacturer of MEAs& development of fuel cell systems OEM focuses on manufacturing & marketing preparation Mass market scale-up – to 100k+ units Year 7: 1 GW Year 2 Year 1 MEA sales Licensing fees MEA sales Licensing fees Partners BUSINESS MODEL FORJOINT DEVELOPMENT AGREEMENT WITH OEMs OR TIER 1s

KEY METRICS 31

POTENTIAL GROWTH CATALYSTS 32

CONTACT ir@advent.energywww.advent.energy