BMW is looking for alternative high-pressure hydrogen storage solutions for box-shaped installation spaces of limited height. While high-pressure hydrogen is conventionally stored in large cylindrical vessels, we are seeking storage systems that can be installed in the space under the floor of a vehicle. Solutions that meet the success criteria will be invited to work with BMW to evaluate and develop the idea.
Future electric vehicles will be powered either by batteries or fuel cells that convert hydrogen to electricity. Currently, the batteries that power electric vehicles are installed in a flat cuboid space. For conventional high-pressure hydrogen storage, large cylindrical vessels are used. In order to use these pressure tanks ‘as is’, the vehicle body would need to undergo massive changes. Since these modifications of the vehicle architecture are very expensive, it is preferable to derive a novel hydrogen storage system that fits into the same installation area as the batteries.
For your concepts please use an exemplary box-shaped space with the following dimensions:
Length 1400 mm, width 414 mm, height 132 mm, leading to an overall volume of about 76.5 liters.
In order to be able to use the hydrogen storage system as soon as possible the final product must be compatible to the current 700 bar hydrogen filling stations.
Key success Criteria
The volumetric efficiency (net volume divided by overall volume) should be high: 0.4 would be satisfactory, 0.6 would be good, 0.8 would be excellent.
The mass of the storage system should be low: 50 kg would be satisfactory, 30 kg would be good, 15 kg would be excellent.
Eventually the final storage system has to fulfill the following set of requirements:
It has to work with SAE J2601 fueling protocol (nominal working pressure: 70 MPa, fueling delivery temperature -40 °C).
Its burst pressure has to be above 157.5 MPa or higher, depending on the materials used.
It must withstand 22,000 pressure cycles from 1.5 MPa to 87.5 MPa.
It has to work in an environment from -40 °C to +85°C.
The storage system filled to 100% must have a steady-state hydrogen permeation of less than 46 ml/hr/l water capacity at 55 °C.
Both early stage solutions and mature solutions, mature solutions > TRL 5 are preferred (Integrated components demonstrated in a laboratory environment)
Designs may refer, but are not limited to:
Several small pressure vessels working in parallel and/or in series to fill the available space.
Vessels with approximately flat walls, using tension elements inside the tank to bridge opposite walls and to avoid bulging under pressure.
Production technologies may refer, but are not limited to:
Fiber braiding, fiber winding and fiber placement
Additive manufacturing (“3D printing”)
Materials may refer, but are not limited to:
High tensile strength fibers (carbon, aramid etc.)
High tensile strength metals and alloys (but don’t forget about hydrogen embrittlement…)
Approaches not of Interest
Storage systems not compatible with SAE J2601 fueling protocol
Storage relying on the exchange of a carrier medium (e.g. LOHC)
Apr 26, 2019
Items to be submitted
To submit your idea or proposal, please use the Respond button at the top of this page. Please note that only non-confidential information can be accepted. By submitting a response: you represent that the response does not contain and will not be deemed to contain any confidential information of any kind; and you acknowledge that BMW may, in their absolute discretion, select or reject a response or any portion thereof.
Your response should be an executive summary of what you are proposing. It should include technical information on how the technology will work in addition to the volumetric efficiency and the mass of the storage system. Information on the background of those involved in the project will also be required in your response to this need posting.