Alpine Alpenglow HY4 prototype showcases hydrogen-burning engine

Alpine has become the latest carmaker to tacitly admit the future might not be entirely electric after all. The brand, which is owned by Renault and which should head to the American market by 2030, has detailed an experimental race car powered by a hydrogen-burning engine.

We say "detailed" rather than "unveiled" because we've already seen this concept: it made its debut as the Alpenglow at the 2022 edition of the Paris auto show. Nearly two years later, much has changed including some of the finer design details, the name (it received the "HY4" suffix), and, crucially, the powertrain. What sounded like little more than a vague simulation in 2022 now has a full set of specifications.

Shaped a lot like a Le Mans racer, perhaps intentionally, the Alpenglow HY4 is a running and driving laboratory built around a carbon fiber monocoque and powered by a turbocharged, 2.0-liter four-cylinder engine that develops 340 horsepower. The engine burns hydrogen, has a 7,000-rpm redline, and is bolted to a sequential transmission with a centrifugal clutch. Alpine claims that its performance is on par with a gasoline-powered 2.0-liter four and quotes a top speed of 167 mph. Burning hydrogen instead of gasoline is harder than it sounds, however.

Hydrogen reaches the cylinders in gas form, so it's more difficult to create a homogeneous mixture than when working with a liquid fuel. Safety is a concern as well: Alpine stores hydrogen in three 700-bar tanks integrated into the sides and the rear of the Alpenglow. There's a pressure-regulating system that gradually lowers the pressure from 700 to 200 and finally 40 bars before the hydrogen reaches the engine.

Alpine's Alpenglow HY4 concept will make its public debut on May 11, 2024, at the 6 Hours of Spa-Francorchamps endurance race; it will be showcased in front of about 70,000 spectators but it will not participate in the competition. The brand claims this is "the perfect opportunity to demonstrate how a hydrogen-powered internal-combustion engine perpetuates the sounds and vibrancy that are the emotional aspects of a racing car." The concept will also make several demonstration runs during the 24 Hours of Le Mans taking place in France in June 2024.

What's next depends on a number of factors, including regulations. For its part, Alpine claims this technology "is a tremendously promising solution for racing and road use." Renault, the Paris-based brand that owns Alpine, agrees: it's "considering various ways" to use what it calls "the hydrogen solution" across its portfolio, including in a hybrid application that pairs a hydrogen fuel cell with an electric motor.

Alpine chose to bypass the fuel cell for the Alpenglow HY4. It notes that burning hydrogen, rather than using it to make the electricity needed to zap a motor into motion, has several advantages. It notably feels similar to a gasoline-burning engine from the driver's perspective, and it sounds similar from the spectator's perspective. This technology is also easier to cool and delivers excellent efficiency under heavy loads.

Last but not least, the Automobile Club de l'Ouest — the sanctioning body that organizes the 24 Hours of Le Mans — will allow hydrogen-powered cars to compete in the race starting in 2027. It's likely not a coincidence that the Alpenglow looks like a Le Mans racer, then.