Hydrogen-powered aircraft
[1] McKinsey & Company forecast hydrogen aircraft entering the market in the late 2030s and scaling up through 2050, when they could account for a third of aviation's energy demand.
The low volumetric energy density of hydrogen poses challenges when designing an aircraft, where weight and exposed surface area are critical.
Fuel cells make sense for general aviation and regional aircraft but their engine efficiency is less than large gas turbines.
[10] Hydrogen aircraft using a fuel cell design are zero emission in operation, whereas aircraft using hydrogen as a fuel for a jet engine or an internal combustion engine are zero emission for CO2 (a greenhouse gas which contributes to global climate change) but not for NOx (a local air pollutant).
[22] In July 2010, Boeing unveiled its hydrogen powered Phantom Eye UAV, that uses two converted Ford Motor Company piston engines.
The aircraft and the electric and energy system was developed within the European Union's ENFICA-FC project coordinated by the Politecnico di Torino.
On January 11, 2011, an AeroVironment Global Observer unmanned aircraft completed its first flight powered by a hydrogen-fueled propulsion system.
[27][better source needed] On 19 January 2023, ZeroAvia flew its Dornier 228 testbed with one turboprop replaced by a prototype hydrogen-electric powertrain in the cabin, consisting of two fuel cells and a lithium-ion battery for peak power.
[30] On 24 June 2024, Joby Aviation's S4 eVTOL demonstrator, refitted with a hydrogen-electric powertrain in May, completed a record 523 miles non-stop flight, more than triple the range of the battery powered version.
[33] Between April 2000 and May 2002, the European Commission funded half of the Airbus-led Cryoplane Study, assessing the configurations, systems, engines, infrastructure, safety, environmental compatibility and transition scenarios.
[35] In September 2020, Airbus presented three ZEROe hydrogen-fuelled concepts aiming for commercial service by 2035:[36] a 100-passenger turboprop, a 200-passenger turbofan, and a futuristic design based around a blended wing body.
[38] In December 2021, the UK Aerospace Technology Institute (ATI) presented its FlyZero study of cryogenic liquid hydrogen used in gas turbines for a 279-passenger design with 5,250 nmi (9,720 km) of range.
[39] ATI is supported by Airbus, Rolls-Royce, GKN, Spirit, General Electric, Reaction Engines, Easyjet, NATS, Belcan, Eaton, Mott MacDonald and the MTC.
Pratt & Whitney wants to associate its geared turbofan architecture with its Hydrogen Steam Injected, Inter‐Cooled Turbine Engine (HySIITE) project, to avoid carbon dioxide emissions, reduce NOx emissions by 80%, and reduce fuel consumption by 35% compared with the current jet-fuel PW1100G, for a service entry by 2035 with a compatible airframe.
[43] On 21 February 2022, the US Department of Energy through the OPEN21 scheme run by its Advanced Research Projects Agency-Energy (ARPA-E) awarded P&W $3.8 million for a two-year early stage research initiative, to develop the combustor and the heat exchanger used to recover water vapour in the exhaust stream, injected into the combustor to increase its power, and into the compressor as an intercooler, and into the turbine as a coolant.
