Study shows research needs for fuel cell trucks
While plug-in electric vehicles are regarded as a sustainable solution for passenger cars, alternative fuel vehicles for heavy duty trucks are still out of sight. A consortium of Fraunhofer ISI, Fraunhofer IML and PTV Transport Consult GmbH has determined the current research needs for fuel cell technology as a drive train for heavy duty trucks in the context of the scientific support of the German Government‘s Mobility and Fuels Strategy.
The German Government passed the Climate Protection Plan 2050 in November 2015. This plan includes the objective to reduce greenhouse gas emissions in the transport sector until 2030 by 40 per cent compared to 1990. However, not only passenger transport has to make a contribution here: Due to its high mileage road freight transport is responsible for approximately one third of the greenhouse gas emissions on German roads. The shift to more energy efficient modes of transport such as ship and railway increasingly reaches its capacity limits.
A possible solution to reducing the greenhouse gas emissions of the road freight transport are fuel cell trucks when the hydrogen is produced from renewable energy. Already today, first drive systems with fuel cells for passenger cars are commercially available, in trucks they are used for example as additional power unit (APU) for secondary aggregates such as the heating. As a drive system for trucks, however, there are additional challenges. These are explained in the study “Fuel cell trucks: critical development barriers, research needs and market potential“ which the Fraunhofer Institute for Systems and Innovation Research ISI, the Fraunhofer Institute for Material Flow and Logistics IML as well as PTV Transport Consult GmbH compiled together.
Dr. Till Gnann, project manager of the study at Fraunhofer ISI explains, “There are similarities for passenger cars and trucks, however, the synergy effects should not be overestimated. It is obvious that the R&D activities for fuel cells in long-haul trucks lie significantly behind those or passenger cars, both nationally and internationally, and there are a number of differences, such as a stronger focus on costs or considerably larger fuel quantities.“
In a total cost of ownership calculation, the fuel costs for long-distance trucks play a significantly larger role than for passenger cars. They sum up to 50 per cent of the kilometer cost when the personnel costs for the driver are disregarded. Therefore, the energy efficiency increase is more significant than the cost reduction for the fuel cell system. The competing technologies for alternative drive trains are also different than for passenger cars: Particularly gas fuelled vehicles (CNG and LNG / compressed and liquefied natural gas) will in future have similar operating costs per kilometer. In addition to costs, there are other requirements for fuel cell trucks: In particular logistics companies expect that vehicles are absolutely reliable as the failure of a truck would involve excessive costs.
Particularly the trucks‘ large tank quantities impose additional conditions for the construction of the vehicles and the setting up of hydrogen fuel stations. A 40 ton vehicle with a conventional drive train today attains a range of up to 2,500 kilometers, with a hydrogen drive it is considerably less. With a pressure of 700 bar, which today is common for hydrogen tanks in passenger cars, a distance between 300 and 400 kilometers is possible without enlarging the space for the tank. Politicians have already reacted to these problems and EU Directive 2015/17 allows that the allowed overall length can be exceeded for alternative drive trains. For this reason, additional tanks can be installed which increase the range up to 1,000 kilometers.
In future research projects, the authors of the study also recommend testing whether shorter ranges are acceptable in order to attain lower investment costs and to speed up the market entry. Dimensioning of hybrid systems of fuel cell and battery and the scaling of the secondary aggregates (e.g. for cooling) should be researched in demonstration projects.
The results of the study were summarized in nine core statements and discussed and validated in a work shop with about 40 representatives from industry, politics and research.
The Fraunhofer Institute for Systems and Innovation Research ISI analyzes the origins and impacts of innovations. We research the short- and long-term developments of innovation processes and the impacts of new technologies and services on society. On this basis, we are able to provide our clients from industry, politics and science with recommendations for action and perspectives for key decisions. Our expertise is founded on our scientific competence as well as an interdisciplinary and systemic research approach.