Aviation · PEM vs SOFC

Aviation use case · side by side

PEM or SOFCfor hydrogen-electric aircraft

Both chemistries run on hydrogen, but they suit different jobs in an aircraft. This page sizes each one from the twin for the three steps of the hydrogen-electric ladder, and sets the results against public roadmap figures. Every model number is a development result, not validated.

PEM model
SOFC model

Fuel-cell explorer

See the system to scale

Cells solid and to scale, balance of plant in grey X-ray. Drag to turn, pinch or scroll to zoom.

Loading the 3D view
  • PEM plates
  • SOFC tubes
  • Balance of plant (placeholder)

Screening estimate from archee.api.system_estimate (also fctwin system). PEM: planar cells, 370 per stack at 1.34 mm, the Toyota Mirai cell thickness [mirai], 280 cm² active area ASSUMED on a plate 2.5 times larger, the Mirai's ratio [doe-mirai]. SOFC reference cell (default): 0.6 W/cm² at 0.8 V, a screening assumption within the published 0.5–1 W/cm² range; high-performance lab cell (switch): 1.0 W/cm² [ma2026]. Both linear cells with open circuit 1.10 V assumed, drawn as 2 mm outer-diameter micro-tubes, 50 mm active, 1 mm gap; packaging assumed, not twin models. SOFC lab rig cell (switch): the twin’s own 7 mm tube (0.22 mm wall, 40 mm active, 9.07 cm²) at a pitch of its diameter plus the model’s 3 mm air gap. Both in bundles of 20 × 20 tubes; details in docs/SOFC_CHECK.md. BoP kW/kW: PEM from the twin's own compressor model (2.51 bar, stoichiometry 2, 68 %, plus 0.3 kW per stack); SOFC blower ASSUMED (stoichiometry 4, pressure ratio 1.1). Mass, today’s hardware (default): PEM stack 2.0 kW/kg [toyota-mirai], PEM system 1.4 kW/kg, a manufacturer claim whose equipment boundary is not reconciled [za600] (DOE 2015 integrated system: 0.659 [doe-targets]); SOFC stack 0.3 kW/kg, midpoint of 0.1–0.5 for planar stacks [bauhaus]; no published SOFC system mass. Development targets (switch): PEM FlyZero stack 7 (2026) to 16 (2050) kW/kg and stack + BoP mid-range [flyzero]; SOFC about 3 kW/kg, the HYLENA target [bauhaus]. BoP mass is system minus stack. Cell W/cm², stack kW/kg and system kW/kg are separate boundaries and are never converted into one another. Ground-level ambient; altitude raises compressor power.

Checked against the Toyota Mirai stack [mirai] [doe-mirai] [anl-mirai]: cells needed at its rated point (378 against 370), compressor power (16.3 against up to 15 kW) and stack volume agree. The twin’s lab cell gave 0.44 V at the Mirai’s 1.9 A/cm² against 0.67 V, so the PEM model was recalibrated: membrane resistance refitted to that one published point (Mirai-class, the default here; switch above). It is a one-point calibration, not a validation, and it over-predicts voltage near open circuit. Stack mass now defaults to the Mirai’s own 2.0 kW/kg. Details: docs/MIRAI_BENCHMARK.md.

Live SOFC calculation

Move the voltage, see the cell

    Benefits and assumptions

    PEM · proton-exchange membrane

    Benefits

    • Starts in under a minute and follows load, including transients [nasa]
    • More power per area: Mirai-class cells give 0.78 W/cm² at 1 A/cm², against 0.60 W/cm² for the reference SOFC cell at 0.8 V [twin] [mirai]
    • Far more power per kilogram today: stacks about 2.0 kW/kg (Mirai Gen1) against 0.1–0.5 kW/kg for planar SOFC stacks [toyota-mirai] [bauhaus]
    • Published flight roadmap: FlyZero 2.0–2.5 kW/kg stack + BoP by 2030 [flyzero]
    • Flown in commuter demonstrators; FlyZero TRL 6 by 2026 [flyzero] [review]

    Assumptions in this twin

    • Mirai-class calibration: membrane resistance refitted to one public Toyota Mirai point (0.67 V at 1.9 A/cm²); other coefficients from the lab anchor
    • 80 °C, 2.53 bar, RH 0.6, cathode stoichiometry 2; sized at 1.0 A/cm² (0.784 V, 63 % LHV)
    • Mass, today’s hardware (default): stack 2.0 kW/kg (Mirai Gen1); system 1.4 kW/kg (ZeroAvia claim, equipment boundary not reconciled; DOE 2015 integrated system 0.659). FlyZero targets appear only under “Development targets”
    • The frozen lab anchor still loses to a fixed 0.7 V baseline on measured lab data (120.6 vs 34.2 mV error)

    SOFC · solid oxide

    Benefits

    • Higher efficiency: 64 % against 63 % (LHV), so 2 % less hydrogen for the same power [twin]
    • Less heat to reject, and at 600–1,000 °C it is high-grade: usable by a turbine or heat exchanger [twin] [review]
    • Fuel flexible and tolerant of CO and other contaminants [nasa] [review]
    • Steady duty suits APU, ground power and turbine-hybrid roles [nasa] [review]

    Assumptions in this twin

    • Reference cell (default): 0.6 W/cm² at 0.8 V, a screening assumption inside the published 0.5–1 W/cm² range; linear cell, open circuit 1.10 V assumed, drawn as 2 mm micro-tubes
    • High-performance lab cell (switch): 1.0 W/cm² at 0.8 V, matching advanced laboratory cells (a metal-foam cell peaked at 1.01 W/cm², 650 °C); not demonstrated stack performance
    • Lab rig cell (switch): the twin’s frozen 7 mm tubular cell at 800 °C, 50 mL/min fuel, 0.24 W/cm² at 0.8 V; fuel-limited below about 0.6 V
    • Sized at 0.8 V (0.75 A/cm² in the selected default)
    • Stack mass 0.3 kW/kg today (planar stacks 0.1–0.5); HYLENA’s about 3 kW/kg is a target, shown only under “Development targets”. No published SOFC system mass, so none is invented
    • Cell W/cm² is never converted to kW/kg: stack mass depends on interconnects, seals, insulation and packaging
    • Start-up (tens of minutes to hours), thermal cycling and altitude not modelled; acceptance gate blocked

    The use case

    Scaling up step by step

    1. Step 1 · by 2030Business + taxi, 4–9 seats350–600 kW
    2. Step 2 · 2030sRegional, 9–100 seats600–2,000+ kW
    3. Step 3 · 2040sLarger single-aisle4+ MW

    Ladder as presented by H2FLY [h2fly]. Sizing below uses the top of each power band.

    From the twin

    What one cell delivers

    PEM leads per square centimetre and, by a wide margin, per kilogram. The Mirai-class PEM cell peaks at 1.41 W/cm²; the reference SOFC cell gives 0.60 W/cm² at 0.8 V, and advanced laboratory SOFC cells reach about 1 W/cm² (the high-performance option). The twin's own rig SOFC cell reaches 0.35 W/cm²: a 7 mm research tube on a small fuel supply, not a stack cell.

    BoundarySOFCPEMSources
    Cell power per active area W/cm²About 0.5–1; advanced lab cells about 1 (1.01 peak, metal-foam cell, 650 °C)About 0.8–1.5[ma2026] [mirai]
    Stack power per kg (no supporting equipment) kW/kgPlanar stacks about 0.1–0.5About 2–3; Mirai Gen1 2.0 (114 kW / 56 kg)[bauhaus] [toyota-mirai] [doe-targets]
    System power per kg (stack + BoP) kW/kgNot publishedDOE 2015 integrated system 0.659; ZeroAvia ZA600 claim 1.4 (boundary not reconciled)[doe-targets] [za600]
    Aviation development ambition (targets) kW/kgHYLENA about 3 for lightweight stacksHT-PEM programmes 3+ at system level (verify included equipment); FlyZero stack + BoP 3.0–3.5 by 2050[bauhaus] [za-htpem] [flyzero]

    Screening benchmarks, not guaranteed continuous ratings. W/cm² is never converted to kW/kg, and cell figures are never relabelled as stack or system figures. Data: datasets/public/sofc-pem-power-density-background.json.

    00.511.522.50.00.20.40.60.81.01.20.00.40.81.21.6Toyota Mirai rated point, 0.67 V at 1.9 A/cm²Current density (A/cm²)Cell voltage (V), solidPower density (W/cm²), dashed
    PEM Mirai-class 80 °CPEM lab cell 75 °C (frozen anchor)SOFC high-performance lab cell (scenario)SOFC reference cell (screening)SOFC rig cell 800 °C Twin model outputs, not validated. PEM Mirai-class: membrane resistance refitted to a public Toyota Mirai point, 2.53 bar; lab cell: frozen anchor, 2.51 bar; both RH 0.6, stoichiometry 2. SOFC reference and high-performance cells: linear screening cells (0.6 and 1.0 W/cm² at 0.8 V). SOFC rig: frozen v1 tubular cell, 3 % steam, 50 mL/min. The rig curve bends down near 0.6 A/cm² because the rig fuel flow runs out (90 % utilisation at 0.5 V); a stack fed more fuel would go further.

    Sized for each step

    Same power, different machines

    Each stack is sized for the net electrical power of the step: PEM at 1.0 A/cm², SOFC at 0.8 V. Which cell you assume changes the answer. At 2,000 kW: Mirai-class PEM vs reference SOFC: hydrogen 96 against 94 kg/h, SOFC area 1.3× PEM; Mirai-class PEM vs high-performance SOFC: hydrogen 96 against 94 kg/h, SOFC area 0.8× PEM; Mirai-class PEM vs rig SOFC cell: hydrogen 96 against 94 kg/h, SOFC area 3.2× PEM; lab PEM vs reference SOFC: hydrogen 115 against 94 kg/h, SOFC area 1.1× PEM; lab PEM vs high-performance SOFC: hydrogen 115 against 94 kg/h, SOFC area 0.7× PEM; lab PEM vs rig SOFC cell: hydrogen 115 against 94 kg/h, SOFC area 2.7× PEM.

    Step 1 · by 2030Business + taxi, 4–9 seats · sized at 600 kWStep 2 · 2030sRegional, 9–100 seats · sized at 2,000 kWStep 3 · 2040sLarger single-aisle · sized at 4,000 kW
    PEMSOFCPEMSOFCPEMSOFC
    Operating point0.784 V · 1.00 A/cm²0.800 V · 0.75 A/cm²0.784 V · 1.00 A/cm²0.800 V · 0.75 A/cm²0.784 V · 1.00 A/cm²0.800 V · 0.75 A/cm²
    Active area76.5 m²100 m²255 m²333 m²510 m²667 m²
    Hydrogen at full power28.8 kg/h28.2 kg/h95.9 kg/h94 kg/h192 kg/h188 kg/h
    Heat to reject359 kW at ~80 °C340 kW at ~800 °C1,196 kW at ~80 °C1,133 kW at ~800 °C2,392 kW at ~80 °C2,266 kW at ~800 °C
    Stack mass today (stack only)300 kg at 2.0 kW/kg1,200–6,000 kg at 0.1–0.5 kW/kg1,000 kg at 2.0 kW/kg4,000–20,000 kg at 0.1–0.5 kW/kg2,000 kg at 2.0 kW/kg8,000–40,000 kg at 0.1–0.5 kW/kg
    System mass today (stack + BoP)429 kg at 1.4 kW/kg (claim)Not published1,429 kg at 1.4 kW/kg (claim)Not published2,857 kg at 1.4 kW/kg (claim)Not published
    Development targets (scenario)240 – 300 kg system (FlyZero 2030)200 kg stack (HYLENA 3 kW/kg)667 – 800 kg system (FlyZero 2035)667 kg stack (HYLENA 3 kW/kg)1,143 – 1,333 kg system (FlyZero 2050)1,333 kg stack (HYLENA 3 kW/kg)
    Step 1 · by 2030Business + taxi, 4–9 seats · sized at 600 kWStep 2 · 2030sRegional, 9–100 seats · sized at 2,000 kWStep 3 · 2040sLarger single-aisle · sized at 4,000 kW
    PEMSOFCPEMSOFCPEMSOFC
    Operating point0.784 V · 1.00 A/cm²0.800 V · 1.25 A/cm²0.784 V · 1.00 A/cm²0.800 V · 1.25 A/cm²0.784 V · 1.00 A/cm²0.800 V · 1.25 A/cm²
    Active area76.5 m²60 m²255 m²200 m²510 m²400 m²
    Hydrogen at full power28.8 kg/h28.2 kg/h95.9 kg/h94 kg/h192 kg/h188 kg/h
    Heat to reject359 kW at ~80 °C340 kW at ~800 °C1,196 kW at ~80 °C1,133 kW at ~800 °C2,392 kW at ~80 °C2,266 kW at ~800 °C
    Stack mass today (stack only)300 kg at 2.0 kW/kg1,200–6,000 kg at 0.1–0.5 kW/kg1,000 kg at 2.0 kW/kg4,000–20,000 kg at 0.1–0.5 kW/kg2,000 kg at 2.0 kW/kg8,000–40,000 kg at 0.1–0.5 kW/kg
    System mass today (stack + BoP)429 kg at 1.4 kW/kg (claim)Not published1,429 kg at 1.4 kW/kg (claim)Not published2,857 kg at 1.4 kW/kg (claim)Not published
    Development targets (scenario)240 – 300 kg system (FlyZero 2030)200 kg stack (HYLENA 3 kW/kg)667 – 800 kg system (FlyZero 2035)667 kg stack (HYLENA 3 kW/kg)1,143 – 1,333 kg system (FlyZero 2050)1,333 kg stack (HYLENA 3 kW/kg)
    Step 1 · by 2030Business + taxi, 4–9 seats · sized at 600 kWStep 2 · 2030sRegional, 9–100 seats · sized at 2,000 kWStep 3 · 2040sLarger single-aisle · sized at 4,000 kW
    PEMSOFCPEMSOFCPEMSOFC
    Operating point0.784 V · 1.00 A/cm²0.800 V · 0.30 A/cm²0.784 V · 1.00 A/cm²0.800 V · 0.30 A/cm²0.784 V · 1.00 A/cm²0.800 V · 0.30 A/cm²
    Active area76.5 m²247 m²255 m²825 m²510 m²1,649 m²
    Hydrogen at full power28.8 kg/h28.2 kg/h95.9 kg/h94 kg/h192 kg/h188 kg/h
    Heat to reject359 kW at ~80 °C340 kW at ~800 °C1,196 kW at ~80 °C1,133 kW at ~800 °C2,392 kW at ~80 °C2,266 kW at ~800 °C
    Stack mass today (stack only)300 kg at 2.0 kW/kg1,200–6,000 kg at 0.1–0.5 kW/kg1,000 kg at 2.0 kW/kg4,000–20,000 kg at 0.1–0.5 kW/kg2,000 kg at 2.0 kW/kg8,000–40,000 kg at 0.1–0.5 kW/kg
    System mass today (stack + BoP)429 kg at 1.4 kW/kg (claim)Not published1,429 kg at 1.4 kW/kg (claim)Not published2,857 kg at 1.4 kW/kg (claim)Not published
    Development targets (scenario)240 – 300 kg system (FlyZero 2030)200 kg stack (HYLENA 3 kW/kg)667 – 800 kg system (FlyZero 2035)667 kg stack (HYLENA 3 kW/kg)1,143 – 1,333 kg system (FlyZero 2050)1,333 kg stack (HYLENA 3 kW/kg)
    Step 1 · by 2030Business + taxi, 4–9 seats · sized at 600 kWStep 2 · 2030sRegional, 9–100 seats · sized at 2,000 kWStep 3 · 2040sLarger single-aisle · sized at 4,000 kW
    PEMSOFCPEMSOFCPEMSOFC
    Operating point0.656 V · 1.00 A/cm²0.800 V · 0.75 A/cm²0.656 V · 1.00 A/cm²0.800 V · 0.75 A/cm²0.656 V · 1.00 A/cm²0.800 V · 0.75 A/cm²
    Active area91.4 m²100 m²305 m²333 m²610 m²667 m²
    Hydrogen at full power34.4 kg/h28.2 kg/h115 kg/h94 kg/h229 kg/h188 kg/h
    Heat to reject546 kW at ~75 °C340 kW at ~800 °C1,820 kW at ~75 °C1,133 kW at ~800 °C3,639 kW at ~75 °C2,266 kW at ~800 °C
    Stack mass today (stack only)300 kg at 2.0 kW/kg1,200–6,000 kg at 0.1–0.5 kW/kg1,000 kg at 2.0 kW/kg4,000–20,000 kg at 0.1–0.5 kW/kg2,000 kg at 2.0 kW/kg8,000–40,000 kg at 0.1–0.5 kW/kg
    System mass today (stack + BoP)429 kg at 1.4 kW/kg (claim)Not published1,429 kg at 1.4 kW/kg (claim)Not published2,857 kg at 1.4 kW/kg (claim)Not published
    Development targets (scenario)240 – 300 kg system (FlyZero 2030)200 kg stack (HYLENA 3 kW/kg)667 – 800 kg system (FlyZero 2035)667 kg stack (HYLENA 3 kW/kg)1,143 – 1,333 kg system (FlyZero 2050)1,333 kg stack (HYLENA 3 kW/kg)
    Step 1 · by 2030Business + taxi, 4–9 seats · sized at 600 kWStep 2 · 2030sRegional, 9–100 seats · sized at 2,000 kWStep 3 · 2040sLarger single-aisle · sized at 4,000 kW
    PEMSOFCPEMSOFCPEMSOFC
    Operating point0.656 V · 1.00 A/cm²0.800 V · 1.25 A/cm²0.656 V · 1.00 A/cm²0.800 V · 1.25 A/cm²0.656 V · 1.00 A/cm²0.800 V · 1.25 A/cm²
    Active area91.4 m²60 m²305 m²200 m²610 m²400 m²
    Hydrogen at full power34.4 kg/h28.2 kg/h115 kg/h94 kg/h229 kg/h188 kg/h
    Heat to reject546 kW at ~75 °C340 kW at ~800 °C1,820 kW at ~75 °C1,133 kW at ~800 °C3,639 kW at ~75 °C2,266 kW at ~800 °C
    Stack mass today (stack only)300 kg at 2.0 kW/kg1,200–6,000 kg at 0.1–0.5 kW/kg1,000 kg at 2.0 kW/kg4,000–20,000 kg at 0.1–0.5 kW/kg2,000 kg at 2.0 kW/kg8,000–40,000 kg at 0.1–0.5 kW/kg
    System mass today (stack + BoP)429 kg at 1.4 kW/kg (claim)Not published1,429 kg at 1.4 kW/kg (claim)Not published2,857 kg at 1.4 kW/kg (claim)Not published
    Development targets (scenario)240 – 300 kg system (FlyZero 2030)200 kg stack (HYLENA 3 kW/kg)667 – 800 kg system (FlyZero 2035)667 kg stack (HYLENA 3 kW/kg)1,143 – 1,333 kg system (FlyZero 2050)1,333 kg stack (HYLENA 3 kW/kg)
    Step 1 · by 2030Business + taxi, 4–9 seats · sized at 600 kWStep 2 · 2030sRegional, 9–100 seats · sized at 2,000 kWStep 3 · 2040sLarger single-aisle · sized at 4,000 kW
    PEMSOFCPEMSOFCPEMSOFC
    Operating point0.656 V · 1.00 A/cm²0.800 V · 0.30 A/cm²0.656 V · 1.00 A/cm²0.800 V · 0.30 A/cm²0.656 V · 1.00 A/cm²0.800 V · 0.30 A/cm²
    Active area91.4 m²247 m²305 m²825 m²610 m²1,649 m²
    Hydrogen at full power34.4 kg/h28.2 kg/h115 kg/h94 kg/h229 kg/h188 kg/h
    Heat to reject546 kW at ~75 °C340 kW at ~800 °C1,820 kW at ~75 °C1,133 kW at ~800 °C3,639 kW at ~75 °C2,266 kW at ~800 °C
    Stack mass today (stack only)300 kg at 2.0 kW/kg1,200–6,000 kg at 0.1–0.5 kW/kg1,000 kg at 2.0 kW/kg4,000–20,000 kg at 0.1–0.5 kW/kg2,000 kg at 2.0 kW/kg8,000–40,000 kg at 0.1–0.5 kW/kg
    System mass today (stack + BoP)429 kg at 1.4 kW/kg (claim)Not published1,429 kg at 1.4 kW/kg (claim)Not published2,857 kg at 1.4 kW/kg (claim)Not published
    Development targets (scenario)240 – 300 kg system (FlyZero 2030)200 kg stack (HYLENA 3 kW/kg)667 – 800 kg system (FlyZero 2035)667 kg stack (HYLENA 3 kW/kg)1,143 – 1,333 kg system (FlyZero 2050)1,333 kg stack (HYLENA 3 kW/kg)

    Screening estimate from archee.api.size_stack: stack only, 100 % hydrogen utilisation, LHV heat basis, no compressor, converter or balance-of-plant losses. Mass rows use today’s published hardware [toyota-mirai] [za600] [bauhaus]; the last row is development targets [flyzero] [bauhaus], not demonstrated. No published SOFC system mass.

    Try it

    Size your own case

    Computed in your browser with the same code as the web API (/api/v1/size); SOFC current density is interpolated from the twin's 800 °C curve.

    Beyond the curves

    How they differ in an aircraft

    PEMSOFCSource
    Operating temperature65–95 °C today; FlyZero target 80 °C (2026) → 100 °C (2035)600–1,000 °C[nasa] [flyzero] [review]
    Start-upUnder 1 minuteTens of minutes to hours (ceramic stack must be heated)[nasa]
    Load followingBase load and transientsBase load only: the ceramic electrolyte limits transient response[nasa]
    Specific power today (published hardware)Stack 2.0 kW/kg (Toyota Mirai Gen1, 114 kW / 56 kg); DOE 2015 integrated system 0.659 kW/kg; ZeroAvia ZA600 system claim 1.4 kW/kgPlanar stacks about 0.1–0.5 kW/kg; no published flight-ready system figure[toyota-mirai] [doe-targets] [za600] [bauhaus]
    Specific power targets (not demonstrated)FlyZero stack + BoP target 1.5–2.0 kW/kg (2026) → 3.0–3.5 (2050); H2GEAR system roadmap (stack + BoP + thermal) 0.92 kW/kg (2025) → 1.3 (2030) → >2.1 (2035); a public 100–400 kW product claims >1.5 kW/kgHYLENA targets about 3 kW/kg for lightweight stacks; NASA claims up to 2.5 kW/kg for an advanced design; no FlyZero target[flyzero] [h2gear] [zeroavia] [bauhaus] [nasa]
    HeatLow-grade, near 80 °C, with stack efficiency typically 40–50 %: large radiators or vapour-compression cooling; HT-PEM (PBI, 30–90 °C hotter) eases thisHigh-grade, hundreds of °C: usable by a turbine or heat exchanger, but complex thermal management[flyzero] [h2gear] [review]
    Fuel and contaminantsNeeds clean hydrogen; CO poisons platinum (HT-PEM is more tolerant)Many fuels (CO is a fuel); tolerant of contaminants[nasa] [review]
    Pressure and cyclingPressurised operation commonSeals limit pressure; needs thermal-cycling capability[nasa]
    Maturity for flightFlyZero: TRL 6 by 2026; flown in commuter demonstratorsLow TRL for flight; no flight role identified in the 2025 review[flyzero] [review]
    Natural aviation roleMain propulsion (Steps 1–3)APU, ground power and turbine-hybrid concepts; long, steady duty[nasa] [review]

    The crossover question

    What a ground deployment proves

    Ground markets can retire some risks before flight. They cannot prove power per kilogram, altitude, vibration or certification, which must be funded as flight-specific work.

    RiskPEM ground routeSOFC ground routeCarries over to flight
    Stack durability under real hoursBackup and ground power, busesData-centre and distributed power (steady duty suits SOFC)Partial: flight duty cycle differs
    Manufacturing cost, yield and UK supply chainVolume from ground marketsVolume from data-centre ordersHigh
    Controls, health monitoring and AIFleet data to train and validate modelsFleet data to train and validate modelsHigh
    Thermal managementLow-grade heat rejection at scaleHigh-grade heat recovery and integrationPartial: ram air and altitude differ
    kW/kg, altitude, vibration, certificationNot proved on the groundNot proved on the groundNone: fund separately

    Same aircraft, third energy store

    Where the battery fits

    Neither cell is flown alone. A fuel-cell regional aircraft also carries a battery buffer for start-up and transients, which the battery twin can size.

    Battery role in a fuel-cell aircraftPublished requirement
    Fuel-cell start-up and transients (regional)50 kWh, 200 Wh/kg, peak above 5C [ati-battery]
    Full electrification, regional / single-aisleAbove 1,000 / 1,500 Wh/kg [ati-battery]
    Scalability of fuel-cell propulsion with battery hybridisationStill unclear; would need much larger batteries [ati-battery]

    Design an aviation pack in the battery twin →Battery twin home

    Where this leaves the twin

    Evidence and limits

    Sources

    1. [flyzero] FlyZero, Fuel Cells Roadmap Report, FZO-PPN-COM-0033 (ATI, March 2022)
    2. [nasa] NASA Glenn Research Center, Fuel Cell and Hydrogen Activities Overview, presented to Robinson Research Institute (Feb 2024)
    3. [review] Gopalasingam, Rakhshani & Rodriguez, Hydrogen Propulsion Technologies for Aviation, Hydrogen 6(4) 92 (2025)
    4. [zeroavia] ZeroAvia, Components brochure (public marketing material)
    5. [h2fly] H2FLY step-by-step scaling (R. Mueller in Leeham News, 12 Oct 2026; Aerospace Global News, 15 May 2026; Fuel Cells Works, 4 May 2026; FLUG REVUE)
    6. [h2gear] Hales et al., H2GEAR: hydrogen-electric propulsion, AIAA AVIATION 2023, doi:10.2514/6.2023-3874 (GKN Aerospace)
    7. [mirai] Yoshida & Kojima, Toyota MIRAI Fuel Cell Vehicle and Progress Toward a Future Hydrogen Society, ECS Interface 24(2), 2015
    8. [doe-mirai] B. James, Fuel Cell Systems Analysis, DOE Hydrogen Program Annual Merit Review 2017 (fc163)
    9. [anl-mirai] Lohse-Busch et al., Automotive fuel cell stack and system efficiency and fuel consumption based on vehicle testing (ANL, OSTI 1606353)
    10. [ati-battery] ATI INSIGHT, Aerospace Battery Requirements (Aerospace Technology Institute, September 2026)
    11. [doe-targets] US DOE, Technical Targets for Fuel Cell Systems and Stacks for Transportation Applications (2015 status)
    12. [toyota-mirai] Toyota, Toyota Ushers In The Future With The Mirai Fuel Cell Car (first-generation stack 114 kW, 56 kg)
    13. [za600] ZeroAvia, Certification-intent fuel cell system replicates full flight profile in ground test (2 Sep 2025; manufacturer claim)
    14. [bauhaus] Bauhaus Luftfahrt, Solid oxide fuel cell technologies for future aviation applications (HYLENA)
    15. [ma2026] Ma et al., A Novel Metal Foam-Supported Solid Oxide Fuel Cell With High Specific Power, Adv. Sci. (2026), doi:10.1002/advs.202517694
    16. [za-htpem] ZeroAvia, High Temperature Fuel Cell Testing Shows Large Power Density Gains (9 Mar 2023; cell-level, forward-looking)
    17. [twin] This twin: archee.api (frozen PEM anchor and SOFC v1 models)