7 days ago
Alpine: hydrogen is ideal for motor sport — but only if you burn it
It's the VHS vs Betamax battle for the new age: battery electric v hydrogen cars. While there is still a vocal minority of people who advocate the latter, most people now recognise that battery-powered cars have emerged as the dominant force.
There are a number of reasons for this. For example, hydrogen might be the most abundant element in the universe but it loves binding to other elements, such as oxygen to create water, so you need to separate it to get the pure gas, and that takes energy. The only way to make it a clean fuel is to use renewables to do this, and that has not always been the case.
The bigger problem is refuelling: it may take longer to recharge a plug-in car, but it's become a lot easier in recent years to find a place to do so — many EV owners can charge up at home, while public chargers can now be found in more than 40,000 locations around the UK, according to Zap-Map's latest figures.
On the other hand, try finding a hydrogen filling station. Only about six sites are accessible to the public, the RAC says, which is down from around ten in 2019. In 2022 the petroleum giant Shell announced the closure of all three of its hydrogen refuelling facilities in Britain amid low demand from motorists. It's no wonder that only two hydrogen cars are at present on sale in the UK, and one of them — the Toyota Mirai — found a grand total of zero homes in 2024.
However, many carmakers haven't given up completely on hydrogen power. It's perhaps no surprise that Alpine, which is known for its lightweight vehicles, believes it still has potential, particularly in motor sport. But only if you burn it in a combustion engine.
'On the roads the main issue today is the network for hydrogen refuelling,' Pierre-Jean Tardy, Alpine's chief engineer for hydrogen technologies, confirms. 'That depends on the politics and the will to build up a network. [But] on the racing side we do not have this problem.'
Although Alpine hasn't made any announcement about whether it will get involved, the World Endurance Championship (WEC), which includes the annual 24 Hours of Le Mans race, intends to introduce a new class for hydrogen-powered vehicles. It was scheduled for 2026 but has been delayed twice, and is at present planned for the 2028 season. Alpine and Toyota have expressed an interest and are developing prototypes.
Alpine's is called the Alpenglow, and rather than using a fuel cell stack, which is found in most road-going hydrogen cars and generates electricity through the electrochemical reaction of combining hydrogen from tanks in the car with oxygen from the air, this prototype has a combustion engine that burns the hydrogen instead of petrol. No carbon dioxide is released in the process, which means that it's a dream for carbon reduction targets. And while you do produce nitrogen oxides in the burning process, Alpine claims existing exhaust technologies can eliminate these before they enter the atmosphere.
A significant advantage for racing, Tardy says, is that a high-powered hydrogen combustion powertrain is lighter than a fuel cell stack with the equivalent output.
'A fuel cell in terms of specific power is less [than hydrogen combustion],' he says. 'Often people say that fuel cells are much more efficient than internal combustion engines. This is true at very low to mid load, but as soon as you draw lots of power from your fuel cell the efficiency drops. Whereas on the internal combustion engine the efficiency tends to increase with the load.'
Tardy says that both combustion engines and fuel cell stacks produce heat, but at high loads the fuel cell becomes more of a problem because combustion engines expel much of their heat through the exhaust.
'You expel at least 25 per cent of the loss of the overall power but most of the loss is put away from the exhaust system. This is not the case for the fuel cell … if you compare the cooling surface of a racing car with a fuel cell compared to an internal combustion engine, it would be much bigger, and this would produce much more drag.'
Tardy says combustion engines are also cheaper to manufacture, owing to the maturity of the technology. A hydrogen combustion engine is essentially the same as a petrol version — you can even run them on petrol, though Tardy says the efficiency drops.
More important, perhaps, for motor sport fans, is that a hydrogen combustion engine still makes a lot of noise.
The Alpenglow originally featured a four-cylinder engine, but a new Hy6 version, developed as a 'rolling laboratory' with a specific focus on racing, packs a twin-turbocharged 3.5-litre V6 that boosts power from 340bhp to 740bhp, with max power coming at 7,600rpm. The top speed is more than 205mph, Alpine claims.
Fans at the Goodwood Festival of Speed this year were treated to the sound it makes during demonstration runs up the hillclimb course, where it wasn't fully stretching its legs, but it proved to be a screamer.
'For sports cars, where the sound, the emotional dimension, the musicality of the internal combustion engine is an important factor for the customer,' Tardy says. 'It makes sense to have this kind of technology [for performance cars].'
The Alpenglow Hy6 stores 160 litres of hydrogen gas in three tanks. Compressed to 700 bar, the fuel weighs about 6.4kg in total.
Alpine is also investigating another technology: liquid hydrogen is more energy dense and quicker to refuel, Tardy says, and at Le Mans the team is imagining being able to carry up to 17kg of fuel, which would be good for about ten laps. That's almost the same range as a current racer in the top-flight Hypercar category, Tardy points out.
Is there a point to all this? Will it have any effect on road cars and the hydrogen refuelling network required? Tardy says battery electric vehicles have a clear advantage now but hopes the future will involve a mix of technologies.
'There will be, of course, lots of battery cars, but it depends on the need of the customers,' he says. 'There is some place, we believe, for fuel cells run by hydrogen. There is also a place for the internal combustion engine, as we develop here, for different applications.
'Racing has not only the ability to develop the technologies very fast, but also it is seen by lots of people everywhere in the world. We have had people who are involved in politics as passengers in this car and they were really impressed. The fact that it is running, it is a reality today, with a prototype car, means that it works. So it is encouraging, I think, for the rest of the network.'
Time will tell, but a cynic would say that for the moment hydrogen road cars won't be viable for at least another 20 years … which is what people said 20 years ago, and 20 years before that.
