Bavarian car manufacturer BMW has shown a prototype of a fuel cell powertrain designed to fit into a conventional passenger car. With this powertrain, the company plans to build a small series in 2022 based on the current SUV model X5. “In the drive system of the BMW i Hydrogen NEXT, the fuel cell system generates up to 125 kW (170 hp) of electrical energy, which is obtained from the chemical reaction of hydrogen and oxygen from the air,” says Jürgen Guldner, Head of BMW Group Hydrogen Fuel Cell Technology and Vehicle Projects. The local emissions of this vehicle thus consist exclusively of water vapor.
The electrical converter, which is located below the fuel cell, adjusts its voltage level to that of the electric drive and the power buffer battery. This is fed by the braking energy and the energy of the fuel cell. The vehicle itself contains two 700-bar tanks, which together hold six kilograms of hydrogen. According to Guldner, this guarantees long ranges in all weather conditions; the refuelling process should only take three to four minutes.
Integrated in this system is also BMW’s fifth generation electric drive, as it is to be used for the first time in the BMW iX3. The power buffer battery, which is positioned above the electric motor, can provide additional energy for short periods, for example when overtaking or accelerating. The total system output is 275 kW (374 hp).
Once the planned small series with this drive has been presented, the BMW Group will then develop a corresponding series model – although this is not expected to happen until the second half of this decade at the earliest; the company also wants to keep an eye on market requirements and general conditions and make possible series production dependent on these conditions.
In a statement, Klaus Fröhlich, the outgoing BMW Board Member for Development, commented on the prospects for fuel cell technology. “We are convinced that various alternative drive systems will coexist in the future, as there is no single solution that covers all the mobility requirements of customers worldwide,” said Fröhlich. “In the long term, hydrogen fuel cell propulsion can become a fourth pillar in our drive portfolio. This is where the upper end of our X family is particularly suitable”.
Fröhlich pointed out that BMW has already been cooperating with Toyota Motor Corp. in the field of fuel cell technology since 2013. From Fröhlich’s perspective, however, the framework conditions for fuel cell technology are not yet such that a series-production vehicle would promise economic success. At least in the short term, the company will therefore not develop such a vehicle. Klaus Fröhlich: “In our view, hydrogen as an energy carrier must first be produced in sufficient quantities, with green electricity and at competitive prices. Hydrogen will then be used primarily in applications that cannot be directly electrified, such as long-distance heavy-duty transport.
In addition, the necessary infrastructure, such as a Europe-spanning comprehensive network of hydrogen filling stations, is not yet in place to bring a vehicle into series production. “However, the BMW Group is continuing its development efforts in hydrogen fuel cell technology with vigour and is using the time to significantly reduce the production costs of the drive system until the infrastructure and a sufficient supply of sustainably produced hydrogen are in place,” said the Development Director.
In order to be optimally prepared for the technological requirements of a hydrogen fuel cell vehicle by the second half of the decade, the BMW Group continues to cooperate with Toyota. Based on a product development cooperation agreement, the two manufacturers are working together on fuel cell drive systems and scalable, modular components for hydrogen fuel cell vehicles.
In the BMW i Hydrogen NEXT powertrain at hand, fuel cells from the cooperation with Toyota are being used. The fuel cell stack and the overall system, however, are original developments of the BMW Group. In addition to the cooperation with Toyota, which is focused on the development and industrialization of fuel cell technology for its mass market suitability, both companies are founding members of the Hydrogen Council, which now comprises more than 80 members.
BMW also emphasizes the importance of the BRYSON research project for the further development of fuel cell technology. The aim of this joint project is the development of H2 tank containers in flat design that can be easily integrated into universal vehicle architectures.