The German Aerospace Center (Deutsches Zentrum für Luft- und Raumfahrt; DLR) has developed a new, innovative small vehicle. The Safe Light Regional Vehicle (SLRV) is extremely light yet very safe. This is ensured by its sandwich design, which weighs only 90 kilograms and yet offers a high level of passive safety. The innovative lightweight concept combines a highly efficient fuel cell propulsion system with safe, resource-conserving mobility. On 1 October 2020, the DLR Institute of Vehicle Concepts presented the first prototype of this light commuter vehicle to the public.
"As a new mobility solution in the light vehicle class, the SLRV demonstrates that we can combine vehicle technology, usage conditions and cost-effectiveness. It lays the groundwork and provides a technology platform for local zero-emission mobility that is quiet and available for personal use," says Tjark Siefkes, Deputy Director of the DLR Institute of Vehicle Concepts.
Sandwich design – lightweight, inexpensive and safe
The body of the two-seater SLRV is 3.8 metres long and low-lying to ensure minimal aerodynamic resistance. It is both lightweight and safe – a combination that existing vehicles in this light vehicle class (L7e) often struggle to achieve. This is possible thanks to the metal sandwich construction method. The material used comprises a metal outer layer and a plastic foam inner layer. The front and rear parts of the SLRV are made of such sandwich panels and serve as crumple zones. These sections also house much of the vehicle technology. The passenger space consists of a shell with an attached ring structure that absorbs the forces that act on the car while driving and protects the occupants in a crash.
Structures utilising sandwich materials have not yet been used for cars in series production. DLR has demonstrated their potential and is now working on the next step – optimising the associated manufacturing technologies.
Zero emissions – a fuel cell / battery hybrid
In addition to its lightweight body, the SLRV also has a highly efficient hybrid propulsion system that ensures its operation is as resource-efficient as possible. The DLR researchers connected a small fuel cell with a continuous output of 8.5 kilowatts to a battery to create the power train. This provides an additional 25 kilowatts of power for accelerating. This combination weighs less than conventional battery systems, provides a range of aproximately 400 kilometres, and enables a maximum speed of 120 kilometres per hour. A 39-litre pressure tank sits inside the vehicle, between the two seats. It can store 1.6 kilograms of hydrogen at 700 bar. The SLRV uses waste heat from the fuel cell to heat its interior. The good thermal insulation of the bodywork, resulting from the use of the sandwich structures, reduces the energy consumption of the vehicle’s air conditioning system in winter.
Enjoyable, sustainable driving – commuter routes, car sharing and shuttle services
With its futuristic, sporty design, the 450-kilogram two-seater is a fully fledged L7e-class vehicle. Among other possible uses, the SLRV would be suitable for commuting, as a shuttle service for taking people to local public transport hubs, and for car-sharing, especially in peripheral urban areas or outside towns and cities thanks to its rapid hydrogen refuelling system. It could supplement local public transport in suburban or rural areas, or serve as an environment-friendly second car.
In terms of purchase price, the SLRV team currently estimates this to be approximately 15,000 euro. With a maximum mileage of 300,000 kilometres and a service life of 10 years, this equates to a price of roughly 10 cents per kilometre.
DLR's Next Generation Car (NGC) project
A total of 20 DLR institutes are working together to develop technology for the next generation but one of road vehicles as part of the Next Generation Car (NGC) project. Alongside the SLRV, there are two other vehicle concepts that also deal with the megatrend of urbanisation. The Urban Modular Vehicle (UMV) is a modular city car for private and commercial users, while the Inter Urban Vehicle (IUV) is designed for longer distances between metropolitan areas.