Tech Insights

Assessing the Role of Catenary Trucks in the Electric Vehicle Landscape

November 15, 2023 by Jake Hertz

Catenary trucks have the potential to significantly curb carbon emissions, but the implementation of these electric transport systems faces major obstacles, a report from Germany finds.

As much of the transportation industry turns to electric vehicles powered by standalone batteries, another branch of electrification is also gaining popularity. Specifically, catenary trucks, powered by direct contact with overhead lines, have become an increasingly attractive option.

 

Catenary truck in Germany.

Catenary truck in Germany. Image used courtesy of Siemens

 

To evaluate the state of the technology, a group led by Fraunhofer ISI put together a report based on the results of three field trials and 12 research projects conducted in Germany.  The major findings of the report provide insight into l the potential and problems of catenary trucks.

 

Environmental Technology Evaluation and Field Trials

A major aspect of the Fraunhofer report was an evaluation of the environmental impact of the technology through a quantifiable analysis of the emissions impact of electric road systems (ERS) compared to conventional diesel trucks. 

The evaluation utilizes a “well-to-wheel” approach, which accounts for the entire energy lifecycle from production to vehicle propulsion. The study specifically highlights that ERS, particularly those utilizing overhead lines, could significantly reduce greenhouse gas emissions. For instance, it was found that trucks using overhead lines for power supply could potentially lower emissions by up to 70% when compared to traditional diesel engines, even when considering the current German electricity mix, which is not fully renewable. This reduction is attributed to the higher energy efficiency of electric drivetrains and the gradual decarbonization of the electricity grid.

 

The principles of an overhead catenary truck.

The principles of an overhead catenary truck. Image used courtesy of Fraunhofer ISI

 

To further support this, the study presents concrete data from trials in Germany, where trucks were equipped with pantographs to draw power from overhead lines on specific highway sections. The trials showed that such trucks could seamlessly switch between electric and diesel modes, ensuring flexibility in areas without catenary lines. The data indicated a reliable operation of the system, with trucks effectively reducing local emissions when powered electrically. 

For example, on the eHighway test track on the A5 motorway near Frankfurt, the trucks demonstrated not only a reduction in carbon dioxide emissions but also in nitrogen oxides and particulate matter, contributing to better air quality.

 

Roadblocks to Catenary Truck Adoption

Despite the potential for catenary trucks, the study identifies several major roadblocks to their widespread adoption.

The infrastructure required for ERS, particularly for systems that use overhead lines, is substantial. The report points out that the installation of catenary systems above roadways represents a significant upfront cost. For instance, the eHighway system on the A5 motorway near Frankfurt required meticulous planning and investment to ensure that the overhead contact lines could be integrated with existing road infrastructure. The scalability of such systems is a further concern, as it necessitates a long-term commitment to expanding the network of electrified roads to ensure that ERS trucks can operate efficiently on major transport routes.

 

The actions required for the successful introduction of overhead catenary trucks.

The actions required for the successful introduction of overhead catenary trucks. Image used courtesy of Fraunhofer ISI

 

Policy and regulatory frameworks are not yet fully aligned with the needs of ERS. Currently, there is a lack of comprehensive legislation that addresses the specific requirements of ERS, such as standardization of technology and interoperability between different systems and across national borders. Moreover, the long-term nature of infrastructure investment requires confidence in the stability of political support, which can be uncertain with changing governments and policy priorities. The study underscores the necessity for consistent and supportive policies that encourage investment in ERS infrastructure and technology.

Finally, public sentiment is a critical factor influencing the adoption of ERS. The report's media analysis reflects a polarized public opinion, with increasing debate and scrutiny over the implementation of such systems. While a segment of the population supports the move towards sustainable transport solutions, there is also significant opposition. Concerns range from the visual impact of overhead lines to the potential disruption during the installation phase.

 

A Field With Huge Potential

The report indicates that ERS, particularly overhead line trucks, present a technologically feasible and environmentally advantageous solution for decarbonizing heavy-duty road transport. However, successfully implementing and adopting ERS on a widespread level will hinge on overcoming significant challenges, including the need for substantial investment in infrastructure, establishing supportive and consistent policy frameworks, and cultivating positive public sentiment and stakeholder engagement. 

The report advocates for a collaborative approach to address these challenges, emphasizing that while the path to ERS adoption is complex, the potential benefits for reducing greenhouse gas emissions and advancing sustainable transport are considerable and worth pursuing.