BMW Launches Pilot Hydrogen Fleet in Europe
BMW has built nearly 100 hydrogen fuel cell versions of its X5 full-size SUV to run as a pilot for various European target groups including media outlets.
After four years of development work, the BMW iX5 Hydrogen vehicle and development project is entering its critical next phase this year and will be tested in real-world situations to gauge consumer demand. The vehicle was first unveiled as a concept at the IAA show in 2019. Initial prototypes were then made available at the IAA Mobility 2021 for visitors to experience in action as shuttle vehicles.
Fuel cell systems for the pilot fleet were built at BMW’s in-house competence center for hydrogen in Munich. This technology is one of the core elements in the BMW iX5 Hydrogen and generates a high continuous output of 125 kW/164bhp. In addition to the technological equivalents of features found on combustion engines, such as charge air coolers, air filters, control units and sensors, BMW also developed special hydrogen components for its new fuel cell system. These include the high-speed compressor with turbine and high-voltage coolant pump, for instance.
The automaker sources the individual fuel cells from Toyota and the two companies been collaborating on fuel cell drive systems since 2013. Fuel cell systems are manufactured in two main steps, based on the individual fuel cells. The cells are first assembled into a fuel cell stack. The next step involves fitting all the other components to produce a complete fuel cell system.
Stacking of the fuel cells is largely a fully automated process. Once the individual components have been inspected for any damage, the stack is compressed by machine with a force of five tons and placed in a housing. The stack housing is manufactured in the light metal foundry at BMW Group Plant Landshut using a sand-casting technique.
For this, molten aluminum is poured into a mold made from compacted sand mixed with resin in a process specially designed for this small-series vehicle. The pressure plate, which delivers hydrogen and oxygen to the fuel cell stack, is made from cast plastic parts and light-alloy castings, also from the Landshut plant. The pressure plate forms a gas-tight and water-tight seal around the stack housing.
Final assembly of the fuel cell stacks includes a voltage test along with extensive testing of the chemical reaction within the cells. Finally, all the different components are fitted together in the assembly area to produce the complete system. During this system assembly stage, further components are fitted, such as the compressor, the anode and cathode of the fuel-cell system, the high-voltage coolant pump and the wiring harness.
In combination with an integrated drive unit using fifth-generation BMW eDrive technology (the electric motor, transmission and power electronics are grouped together in a compact housing) at the rear axle and a power battery with lithium-ion technology developed specially for this vehicle, the powertrain channels maximum output of 295kW/395bhp onto the road. In coasting overrun and braking phases, the motor also serves as a generator, feeding energy back into a power battery.
Performance
The hydrogen needed to supply the fuel cell is stored in two 700-bar tanks made of carbon-fiber reinforced plastic (CFRP). Together these hold almost 13lbs of hydrogen, enough to give the BMW iX5 Hydrogen a range of 313 miles in the WLTP cycle. Filling up the hydrogen tanks only takes three to four minutes, so the vehicle can also provide the driving over long distances, with just a few short stops along the way. Claimed performance achieves acceleration from standstill to 62mph in under 6 seconds and a top speed of 112mph.
Oliver Zipse, chairman of the board of management of BMW, said: “Hydrogen is a versatile energy source that has a key role to play in the energy transition process and therefore in climate protection. After all, it is one of the most efficient ways of storing and transporting renewable energies. We should use this potential to also accelerate the transformation of the mobility sector. Hydrogen is the missing piece in the jigsaw when it comes to emission-free mobility. One technology on its own will not be enough to enable climate-neutral mobility worldwide.”
— Paul Myles is a seasoned automotive journalist based in Europe. Follow him on Twitter @Paulmyles_
