Alpine Alpenglow Hy4: a rolling prototype with a hydrogen-powered internal combustion engine that will excite motorsport fans
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The first rolling version of the Alpine Alpenglow prototype (named Hy4) will be presented at the Spa-Francorchamps Circuit on 10 May 2024 before it takes to the track for the first time on 11 May for the sold-out TotalEnergies 6 Hours of SpaFrancorchamps endurance race. It will also make demonstration runs at the 92nd edition of the 24 Hours of Le Mans on 14 and 15 June 2024.
• Following on from the Alpine Alpenglow concept car presented at the 2022 Paris Motor Show, the Alpine Alpenglow rolling lab Hy4 proves by running on a racetrack that performance and sustainable development are compatible, with the added thrill of the sound of an internal combustion engine. Its name combines the notion of hydrogen ‘Hy’ and 'four' for 4 cylinders.
Alpine is reconciling environmental innovation and performance through its hydrogen combustion engine technology. This technology offers a new approach to decarbonizing motor racing and a possible avenue for sports cars.
Under the spotlights of the 2022 Paris Motor Show, Alpine presented its Alpenglow concept, a veritable manifesto of the brand’s future directions in design and sustainable innovation, the “mother of all future Alpines”. This founder model embodied the brand’s ongoing research into hydrogenpowered combustion engines for sports cars, with the potential for high performance both on the road and in competition, in line with the brand’s ambitious decarbonisation targets. Alpine is therefore ready for possible changes in future regulations.
Today, the Alpine Alpenglow Hy4 is no longer just a concept car but has become a genuine rolling lab designed as a racing car with its carbon monocoque and turbocharged 2.0-litre 4cylinder engine develops 340 bhp. After a presentation within the confines of the circuit on 10 May, Alpine Alpenglow Hy4 will make its public debut on 11 May 2024 before the TotalEnergies 6 Hours of Spa-Francorchamps Endurance Race (FIA WEC) and its 70,000-plus spectators. It will be the perfect opportunity to demonstrate to motorsport enthusiasts how a hydrogen-powered internal combustion engine perpetuates the sounds and vibrancy that are the emotional aspects of a racing car. The feeling is intensified by the very spectacular design of the Alpine Alpenglow Hy4, which is further enhanced in this version.
Alpine Alpenglow Hy4 will also make demonstration runs during the 92nd edition of the 24 Hours of Le Mans on 14 and 15 June 2024.
The significance of the name Alpenglow takes on its absolute meaning with this rolling lab: the optical phenomenon that casts a glowing light over the mountains before sunrise perfectly symbolises the dawn of a new world.
Renault Group: a genuine commitment to hydrogen, with complementary technologies
The hydrogen solution is being considered in various ways throughout the Renault Group, contributing to its carbon neutrality objectives in Europe by 2040 and worldwide by 2050.
With HYVIA (a joint venture with Plug), Renault Group offers a complete and unique ecosystem that includes fuel cell-powered light commercial vehicles, hydrogen recharging stations, fleet financing, and maintenance services.
Renault Group is also developing hydrogen combustion engines for high-powered extra-urban commercial use and specific sportier purposes.
The Renault brand is also developing a hybrid technology that combines an electric motor with a hydrogen range extender powered by a fuel cell.
Alpine firmly believes in the role of motorsport as an accelerator for the development of future mobility technologies. The hydrogen-powered internal combustion engine is a tremendously promising solution for racing and road use. Alongside the rolling hydrogen version of Alpenglow, Alpine is gearing up for some exhilarating times with the launch of seven new electric models between now and 2030, starting this year with the A290, its sporty city car and the first electric model from the Alpine Dream Garage.
Exterior design
Alpine Alpenglow is a seminal prototype for the design of the brand’s future models. Very close to the 2022 concept, the Alpine Alpenglow Hy4 rolling lab is even better proportioned, the form following the function, with a redesigned crash box (element for absorbing impact energy), an enlarged interior to accommodate two seats, and greater height, while retaining the locations of the hydrogen tanks still located in the side pods and behind the cockpit. The tracks have been widened to 2.10 m for a total width of 2.15 m, a length of 5.20 m and a height of 1.10 m: ideal proportions. The visual connection has thus been established with the Alpine A424 competing in the prestigious Hypercar category of the World Endurance Championship.
The front end of the hydrogenpowered Alpine Alpenglow is designed to evoke the sensation of a comet arriving from outer space, its speed and penetration of the atmosphere suggested by the ‘cosmic dust’ light particles in the four front lights and the magenta-coloured dorsal contour. The latter turns blue as it reaches the rear of the prototype, as do the vertical lights next to the vertical titanium exhaust pipes, symbolising the hydrogen and water vapour that its combustion emits.
The aerodynamic aspects of this prototype are an integral part of its design and have been the subject of an ongoing dialogue between Design and Engineering. In a subtle compromise between speed and downforce, the front splitter has been redesigned, creating a vast low air intake that flows over the cockpit and tapers at the rear like a drop of water, letting the airflow under the rear deck. New NACA air intakes are integrated to serve the oil and water radiators, and the snorkel takes on a shape closer to that of a racing car. The long-tail rear end is reminiscent of the Alpine A220 racing car of the late 1960s. Alpine Alpenglow Hy4 uses the low, transparent spoiler first seen on the concept car for its hydrogen-powered rolling version. The rear diffuser has been redesigned for greater aerodynamic efficiency.
Every design element has been thought through to the finest detail, like the wheel rims with a structure and gradient that evoke
speed even when stationary, in perfect harmony with the bespoke tyres produced by Michelin, whose graphics match the design of the rims. On the classic carbon bodywork, the centreboard and snorkel are designed in forged carbon, revealing the raw material, like an evocation of the mineral world of the mountains, a typical Alpine element. Like the exposed technical parts accessible to the outside eye, an air intake is open to the cockpit, giving a glimpse of the onboard ambience, highlighted by a triangle of light that energises the concept’s styling even further.
Interior design
The elytra-shaped door opening kinematics are designed to free up as much space as possible, facilitating access to the cockpit. The driver and passenger can then slide over the side pods, which slope towards the cockpit, to reach the perfectly fitting moulded bucket seats.
The triangle at the front of the cockpit is also a typical Alpine feature, evoking the mountains. It provides several visual functions for the driver: an impulse, a direction, and it can change colour like in a video game to evoke, for example, the level of the lateral
Gs in real time, engine speed, or to give information on travelling speeds.
The dash panel features a magenta tubular crossbar partially concealed by an aircraft wingshaped section. The materials used are reminiscent of the world of sports cars, with carbon fibre, aluminium, and Alcantara trim embellished with 3D-printed motifs. There’s also a magentacoloured starter button, control buttons taken from the Alpine A110 and a racing steering wheel sourced directly from Alpine’s racing cars. On the sides, the carbon skin covering the side tanks portents their shape. Lastly, dedicated spaces have been integrated for mounting mini action cameras to capture the sound and images of laps around the track in the hydrogen-powered rolling version of Alpine Alpenglow.
Hydrogen power: 340 HP that roars
The Alpine Alpenglow hydrogen-powered rolling lab is designed like a racing car with an LMP3 carbon chassis. Under the Alpine Alpenglow Hy4 carbon bonnet is a 2.0-litre in-line 4cylinder turbocharged development engine delivering 340 bhp (250 kW). It is fuelled by hydrogen (more precisely, H2 dihydrogen) with direct injection at 40 bar pressure and water injection to reduce NOx emissions. It can reach a maximum of 7,000 rpm and is coupled to a sequential racing gearbox with a centrifugal clutch. The performance is comparable to the petrol equivalent, with a top speed of approximately 270 km/h.
Developing such an engine requires very specific work because hydrogen is injected in gas form, making it more challenging to create a homogeneous mixture than petrol, which is injected in droplet form. Hydrogen can burn at a much more comprehensive range of concentrations, from 4% to 76%, with both lean and rich mixtures. In all cases, abnormal combustion must be avoided, which means preparing a homogeneous mixture and controlling the temperature in the combustion chamber. The adaptation work carried out on the Alpenglow engine Hy4 has contributed to enriching the expertise of Alpine Racing engineers in the development of a new Alpine engine entirely designed to be hydrogen-powered, with the presentation of a second rolling version before the close of 2024.
The three Alpenglow tanks Hy4 store hydrogen in gas form (2.1 kg each) under high pressure: 700 bars. They are located in the side pods and aft of the cockpit, in ventilated compartments and sealed off from the interior. A pressure regulator reduces the pressure from 700 to 200 bars before lowering it to 40 bars with direct injection into the combustion chamber.
Numerous measures have been taken to ensure absolute safety. Composite cylinders under 700 bars are “Regulation 134”* certified, valves are installed for rapid evacuation in the event of a fire, hydrogen presence sensors keep a constant watch, a rigorous start-up procedure is in place with numerous checks. Finally, a colour-coded system alerts the driver and emergency services according to the degree of urgency of each type of incident.
*Regulation 134: European type-approval standard for the safety of hydrogen-powered vehicles.
Hydrogen in racing, A promising technology with great potential
The two principal solutions for hydrogen-powered propulsion are the fuel cell (which produces electricity to power an electric motor) and the internal combustion engine powered directly by hydrogen. Alpine has opted for the latter, as it combines a host of advantages for a racing car, not least the very similar feel of the engine for the driver and a sound ideally suited to Alpine’s racer philosophy. Among these advantages are its specific power, excellent efficiency under heavy loads, and reduced cooling requirements, as heat is dissipated through the exhaust rather than through radiators. The environmental aspects are also naturally very favourable: its CO2 emissions are negligible, it produces no soot, CO or unburnt hydrocarbons, and NOx emissions can be reduced to levels unattainable for fossil fuel engines.
These arguments favour continuing along this path after this first rolling version, which continues to be the subject of research and development to optimise this type of promising engine further. Regarding hydrogen storage solutions, Alpine is one of the leading manufacturers with a view to switching to liquid hydrogen, a paradigm-changing state of the art that can be better integrated into the car and refuelled quickly.
Alpine Racing is paying close attention to changes in competition regulations and notes that the ACO will authorise hydrogenpowered cars from the 2027 24 Hours of Le Mans onwards. Formula 1 engines could also switch to hydrogen by 2031.
Guillaume De Ridder, Alpine Racing engineer and race car driver
The driver behind the wheel of the Alpine Alpenglow Hy4 for its first track laps at Spa-Francorchamps has a unique profile: Belgian Guillaume De Ridder is both a rallycross champion and engineer at Alpine Racing. An atypical career that began with years of motor racing in a wide range of disciplines: karting, circuit racing and rallying, culminating with the 2021 FIA RX2e rallycross title.