Future runway drives should be electric.
Future runway drives should be electric.
( Source: gemeinfrei / Unsplash)

VDE Report Electric motor as the only alternative to diesel drive

Author / Editor: Gerd Kucera / Florian Richert

On 106 pages, the VDE summarises the results of its study on mobility, environmental and climate aspects of rail diesel traffic and recommends full electrification using electric drive technology.

According to its study, VDE calls for differentiated drive systems as an alternative to diesel rail transport. The VDE believes that full electrification is ideal, but economic considerations hinder the implementation, which is so urgently needed for reasons of climate policy. Nonetheless, the VDE analysis shows that nothing stands in the way of a differentiated use of different drive systems, provided that the planning approval procedure is accelerated.

"Dr. Wolfgang Klebsch, mobility expert at VDE and co-author of the study, states that "the most sensible way to replace the diesel train is to use an electric motor, as in the case of the electric train with overhead contact line and the battery and fuel cell train. The VDE experts recommend promoting battery and fuel cell as equal drive technologies. In addition, the current planning approval procedure for electrification must be simplified".

The rail network has an operating distance of approx. 34,000 kilometres and, with 108 rail metres per km2, is one of the densest networks in the world. At 59%, the degree of electrification, on the other hand, is only average in Europe. Limited electrification affects regional rail passenger transport in particular. Zero emissions and climate neutrality are central evaluation criteria for new drive solutions.

VDE study evaluates alternatives to diesel multiple units and shows solutions

In the long term, a more intensive use of the existing rail network is necessary through more dense intervals as well as further line expansion and the reactivation of closed lines. A prerequisite for this would ideally be complete electrification of the rail network.

In Germany, only 40% of the rail network is currently not electrified - a value below the European share. A good third of the train kilometres travelled in Germany are served by diesel trains, often on tracks with existing overhead lines. With regard to the pollutant emissions of diesel trains, other drive systems are in demand for these lines. Existing technology is efficient and applicable. In its study "Alternatives to Diesel Multiple Units in Local Rail Passenger Transport", conducted as part of a development promotion project by the Ministry of Transport and Digital Infrastructure (BMVI), the VDE technology association shows which type of drive promises the most success for which type of line. The study serves as a decision-making aid for alternative forms of propulsion and is aimed at those responsible for local transport.

Electrification most reasonable, but decelerated

The authors generally see electrification as the most sensible solution, provided that it is economical and involves a high volume of traffic. The current diesel routes, however, are weak. Electrification, on the other hand, is cost-intensive with up to € 2 million per km and entails high maintenance costs. Even if there were sufficient financial resources, electrification would take too long due to the current complex planning approval procedure, which can take up to 10 years. Alternatives are therefore in demand.

Hybrid drives are no suitable alternatives

Equipping the diesel multiple-unit train with an electric motor, as in the case of the electric multiple-unit train with overhead contact line and the battery and fuel cell multiple-unit train, is a real solution. Because electric motors are emission-free and climate-neutral when green electricity is used. The authors exclude hybrid drives as an alternative: Given the decision to decarbonise transport by 2050, this investment would be an expensive transitional solution. For the authors, the battery train is the most sensible solution for lines with catenary gaps of 40 to 80 km, where the battery can be charged under a catenary. On lines with larger catenary gaps, the battery multiple unit is also an option if electrification islands are provided. However, the fuel cell is the best energy solution for railway lines that have to get by completely without overhead lines or have gaps of well over 80 km. The only exhaust gas produced here is clean water vapour. In that case, a hydrogen filling station network is necessary, the operation of which requires a functioning hydrogen production industry.

Current planning approval procedures prevent traffic turnaround

In order to be able to implement the traffic turnaround quickly, the VDE demands a consistent simplification of the planning approval procedure. The further development of the alternative drive concepts up to series maturity should also be accompanied by intensive funding measures - irrespective of the technology. In short: batteries and fuel cells must be promoted on an equal footing. The VDE experts claim that the risk of their implementation must be mitigated with political support.

What does planning approval mean? In Germany, planning approval is an administrative procedure with regard to the admissibility of spatially important projects and infrastructure measures. By definition, spatial planning, including its spatial development plans, is any project or measure that takes up space or influences the spatial development or function of an area. This includes the use of the public funds earmarked for this purpose. Projects of spatial significance, such as a railway line, affect a large number of public and private interests because of their spatial dimensions and actual impacts (noise, environmental impact, costs). They create tensions that need to be overcome in relation to construction projects carried out on a single site. These concerns require special determination and consideration in a formalised procedure, the planning approval procedure.

According to the coalition agreement of the Federal Government of March 2018, traffic in Germany is to be completely decarbonised, in other words climate-neutral, by 2050. The results and conclusions are presented in this study.

The study can be downloaded for free (in German).

This article was first published in German by Elektronik Praxis.