Can a hydrogen fuel cell be an alternative? We drove the BMW iX5 Hydrogen in the snow
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BMW iX5 Hydrogen 8 scaled 1

We were less than 60 km from the arctic circle to drive a prototype of the BMW iX5 Hydrogen and we came back very impressed.

BMW is revisiting the use of hydrogen as a solution for car locomotion. We were on the road, close to the arctic circle, with a prototype of the iX5 Hydrogen and we came back very impressed with the dynamics of this SUV, of which there will be a first small series by the end of the year.

We are at the BMW Group’s 28-hectare winter testing facility on a test circuit, ie where the chaff is separated from the wheat in terms of dynamics and handling.

Even more so because in some sections we ride over a frozen lake (one of almost 9000 in this region) near Arjeplog, in northern Sweden, 55 km southwest of the arctic circle.

The Munich SUV does not hesitate and passes even the most difficult surfaces with a slight drift from the rear, which does not create problems for the driver there and beyond, with the help of suitable winter tires that guarantee sufficient levels of traction and grip.

In addition, the fact that we can switch to B mode is a great help to regain the proper trajectory and to get rid of the excessive symptoms of «loose rear» in this electric rear-wheel drive SUV.

But before we continue to «dissect» the behavior of this BMW iX5 Hydrogen, let’s go to a preview.

Who sees faces…

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BMW iX5 Hydrogen

Apart from all this additional equipment inside, everything looks quite «normal», even if this X5 of normal has little, being a prototype called iX5 Hydrogen, that is, a hydrogen fuel cell electric vehicle (FCEV), exhibited by first time publicly at the Frankfurt Motor Show in 2019.

Hardly any differences are noticeable in the handling relative to the iX, BMW’s other large electric SUV, but the battery (BEV) as this iX5 dominates the ice lake as easily as it advances on snow-covered roads.

But all this without the inconvenience of seeing its autonomy drastically reduced by negative air temperatures or by the permanent use of air conditioning.

Both the iX and iX5 Hydrogen weigh the same 2.5 tonnes, as does the X5 plug-in hybrid (PHEV), which provided the technical basis for this prototype. The high mass also helps explain why the BMW iX5 Hydrogen feels a little power-shy in Comfort mode (in which steering is also a bit vague).

What seems obvious is anything but trivial. Because many elements have to be perfectly combined with each other to allow competent behavior.

These Bavarian engineers are breaking new ground in many respects with the BMW iX5 Hydrogen, especially as they set out to make a fuel cell vehicle that creates a peak power of 275 kW (374 hp), i.e. the most powerful already installed in a light passenger vehicle. Continuous power, on the other hand, is much lower, at 125 kW or 170 hp.

To ensure that this level of performance can be generated, an electric turbocharger takes care of filling the pressurized oxygen, allowing the hydrogen to react with the oxygen and generate electricity. And here, one of the big challenges is ensuring that “the fuel cell works right away”, explains technician Robert Halas.

3 to 4 minutes for 500-600 km

The heart of this fuel cell system is located in the engine compartment and is similar in size to a three-cylinder combustion engine, weighing around 180 kg.

The two carbon fiber tanks, in which hydrogen is stored at a pressure of 700 bar, are located under the rear seat and in the center tunnel (transmission tunnel on the X5 combustion engine) in a “T” configuration, and have a of 6 kg, providing a range of 500 km to 600 km, and complete refueling can be done at an H2 station in just three to four minutes.

The most powerful with hydrogen fuel cell

At BMW, dynamics are always at the top of priorities. That’s why there’s a 150 kW high-voltage battery with a capacity of 2.3 kWh under the boot floor, which acts as a power reserve to boost the system’s power to 275 kW (374 hp) for a limited period of time. or special wishes for top-level performances. Just press the Sport mode button and have fun… while it lasts.

Power comes from a fifth-generation BMW electric motor that drives the rear axle. Using only the electric battery, the hydrogen fuel cell iX5 has a range of 10 km to 15 km. The special feature of this battery is that it supplies energy very quickly and the cells can be recharged just as quickly.

It reaches the 100 km/h mark in less than seven seconds, then can accelerate to a top speed of 190 km/h. To ensure that boost is always available, the fuel cell system charges the battery at high voltage so it always has a charge level between 60% and 80%.

The BMW iX5 Hydrogen has no other restrictions: the boot is as big as the plug-in hybrid X5 xDrive45e, and the air suspension chassis guarantees more than enough comfort.

Juergen Gueldner, vice president of BMW Hydrogen Fuel Cell Technology and Vehicle Projects, is proud of the fact that the fuel cell responds to accelerator pedal commands without any delay.

This is BMW’s second attempt to develop an FCEV, after the 5 Series Gran Turismo in 2015, which marked the first collaboration with Toyota in this field.

Compared to this project, the joint German-Japanese initiative managed to significantly increase the energy density in this iX5 Hydrogen, which combines Toyota cells with a fuel cell module and software supplied by the Bavarians.

The other big help in improving this experimental propulsion system came from the latest generation, the fifth, of the BMW eDrive system on which it is based.

However, instead of drawing electricity from the high voltage battery system as in the iX, it obtains it from cells that convert compressed hydrogen into electricity (there is then a converter to modulate the voltage so that it can be used by the electric motor).

Chemistry question

This chemistry combines hydrogen and oxygen atoms, but if we just fill a container with gases from these two elements, they won’t be able to form water on their own. This will only happen if the hydrogen and oxygen molecules are excited, accelerating them and causing them to collide with more energy, which can then form water.

Comparing hydrogen fuel cell electric vehicles (FCEV) with battery electric vehicles (BEV) or combustion engine vehicles can help to understand why it has not yet been adopted as the primary solution for a much-desired carbon-neutral future, the holy grail of the third millennium.

It is that the energy density of hydrogen per kilo, despite being about three times greater than that of gasoline, as it is the lightest element that exists, it needs to be strongly compressed to become dense (and still far from corresponding to the density of gasoline energy).

This means that hydrogen is not a suitable solution for internal combustion engines, which are less efficient than electric motors; in comparison with a battery-electric one, there are some indisputable advantages, as a fuel cell system can provide adequate amounts of electricity.

And even when it’s close to being empty, a fuel cell module continues to generate high voltage, unlike batteries, and that explains the huge importance of battery management and preventing the battery charge from dropping below a predefined threshold and is absolutely vital in terms of life expectancy and general functioning.

Small series in production this year

Anyone who thinks the BMW iX5 Hydrogen is just a fun exercise for tech-savvy engineers is wrong.

At the end of the year, a small series of hydrogen fuel cell SUV will be produced and by the end of the decade it is estimated that these fuel cell versions will cost as much as the equivalent battery-electric ones, promising to be 100 kg. lighter and offer similar autonomy.

A few months later, there will also be an iX5 Hydrogen all-wheel drive, with the addition of a second electric motor on the front axle, installed under the fuel cell module.

According to BMW’s strategy, battery and fuel cell electric vehicles should share the same platforms, as these synergies keep costs down. The fuel cell in a car is no different from the one in a truck, the platinum content is gradually reduced and it is a recycled product from catalytic converters in vehicles with internal combustion engines.

Infrastructure expansion

The coexistence of hydrogen and battery-electric mobility also seems possible. According to the Hydrogen Council study “Roadmap to zero Emissions”, the CO2 balance of battery electric vehicles and fuel cell electric vehicles is not that different when considering the entire life cycle.

Furthermore, in battery electrics, electricity must always be produced close to the grid, while hydrogen can be transported over long distances by ship or pipeline.

The UAE has been exploring the idea of harnessing solar energy to produce green hydrogen for some time and has set up a working group with Germany.

Whether it comes from solar or wind energy, the great advantage of hydrogen is that it can be used not only as ‘fuel’, but also as stored energy.

On the one hand, due to the extensive network of existing pipelines, it should be possible to free some sections for hydrogen, but on the other hand companies such as Linde Engineering are studying a way to pass the two gases through the tubes and then separate them when arrive at their destination with the help of membranes. A first pilot factory has already been opened in Dormagen (Germany).

BMW supports the AFIR (Alternative Fuel Infrastructure Regulation), which aims to ensure that the network of hydrogen filling stations is so widespread that the distance between filling stations along the main traffic arteries is no more than 150 km.

And that’s not even enough for the Munich brand: if BMW manages to get its way, those differences must be reduced to less than 100 km by 2027.

Source: BMW


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