Hydrogen light motorcycle at the DHBW Mannheim – Sustainable mobility project successfully completed.
An electric light motorcycle with a range of 150 km and refueling in under a minute? The DHBW Mannheim has figured out how to do it. At the end of 2021, SOL Motors GmbH presented its idea at the Innovation Challenge Mobility and Production : The start-up from Böblingen wanted to turn its light motorcycle “Pocket Rocket” into a “Pocket Rocket H2” using a fuel cell drive.upgrade.
The research team around Prof. Dr. Volker Schulz from the Baden-Württemberg Cooperative State University (DHBW) Mannheim presented a convincing approach, prevailed against rival competitors and received funding for the project from the Ministry of Science, Research and Art over a period of 16 months. Now the – partly surprising – results of the feasibility study are there and enable the next step towards the prototype.
E-bikes, e-scooters and e-scooters have already become part of the cityscape. Small motorcycles, so-called light motorcycles, are currently being developed in the electric sector. With an eye-catching design, the “Pocket Rocket” from SOL Motors is coming onto the market this fall. The battery-electric version is available in two variants with top speeds of 45 km/h or 80 km/h.
In both cases, the range is 50 to 80 km and it takes around three hours to charge the battery from a household socket. If you use the Pocket Rocket for your daily commute to work, that is usually sufficient. However, there are also cases in which you want the shortest possible charging time and a long range, eg when using light motorcycles in disaster relief.In addition to a high range, continuous availability is required. Conditions that a fuel cell vehicle meets.
Fuel cell as a range extender
But how can you integrate a fuel cell system, a hydrogen tank and the battery required for launch into the Pocket Rocket in such a way that the range is increased, but the weight remains almost the same and no higher costs are incurred?
After intensive research including calculations and setting up a laboratory model,Prof. Dr. Volker Schulz, research assistant Kai Tornow and Prof. Dr. Wolf Burger (DHBW Stuttgart, Horb Campus) has an answer: Instead of a pure fuel cell drive, the fuel cell is used as a range extender. It is primarily used to charge the battery. The fuel cell system allows the battery to be reduced from 2.5 kWh to 0.35 kWh with the same engine power (1,000 W).
Record values for range and refueling time
The battery size does not change the range of the vehicle because it only depends on the tank volume. The hydrogen consumption is around 200 g per 100 km – so with 1 kg of hydrogen the Pocket Rocket H2 could travel 500 km. The problem: Even when compressed, 1 kg of hydrogen has a volume of almost 40 liters and weighs 24 kg, which is too much for a light motorcycle. So the team decided on a tank volume of 350 g, so that the hydrogen-powered Pocket Rocket H2 could travel around 150 km.
“It’s amazing that the Pocket Rocket H2 is only around 2 kg heavier than the battery-electric version. And that with twice the range! By reducing the size of the battery, we save almost 12 kg – weight that we use for the new components such as the fuel cell (4 kg) and tank (9 kg).Refueling is also quick, the hydrogen tank is full again after just 14 seconds.
Another advantage of this approach: The electrical connection as a range extender represents only minimal intervention in the control system and is particularly suitable for retrofitting battery-electric vehicles,” reports Prof. Dr. Volker Schulz. In a follow-up project, the laboratory setup and Pocket Rocket will become one real hydrogen light motorcycle.
Technological advantage thanks to cooperation between industry and universities
The “Pocket Rocket H2” project was funded by the Ministry of Science, Research and Art of the State of Baden-Württemberg as part of the Innovation Challenge Mobility and Production 2021.
Petra Olschowski, Science Minister said:
The ‘Pocket Rocket H2’ project is an excellent example of how project ideas from industry, combined with the research strength of our universities, can be implemented in a short time and thus make technological advances possible.
From the project submission to the funding decision in just two months: the Ministry of Science’s Innovation Challenge has more than proven itself as a format for building bridges between business and science as quickly as possible. “The business location benefits permanently from these collaborations.
READ the latest news shaping the hydrogen market at Hydrogen Central
Hydrogen light motorcycle at the DHBW Mannheim, September 20, 2023
