On 17 and 18 May 2025, the "Climate-friendly Lake Constance" pilot project was launched at the Ultramarin Boatshow in Kressbronn. Under the motto "Cast off for the future", the project marks an important milestone for sustainable mobility on the water. The aim is to gradually convert private pleasure boats and yachts on Lake Constance to climate-neutral fuels and thus contribute to the realisation of the regional climate targets by 2040. The project, which is subsidised by the Baden-Württemberg Ministry of Transport, focuses specifically on the use of alternative fuels in leisure boating.
Innovative fuels for Lake Constance
Two climate-friendly fuels are at the centre of the pilot project: HVO100 and Nautic E10. These are now for three Lake Constance petrol stations are planned or available. HVO100 (Hydrotreated Vegetable Oil) is a diesel fuel that is produced from waste and residual materials such as used cooking oils or animal fats. It has the potential to reduce CO₂ emissions by up to 90 per cent over the entire life cycle compared to fossil diesel. HVO100 also impresses with a water protection class 1 rating, lower particulate and pollutant emissions and quieter running engines.
Nautic E10 is a petrol fuel with a 10 percent bioethanol content that has been specially optimised for use in boats. It enables CO₂ savings of around 8.5 per cent. A special additive prevents the build-up of water feared by many boaters and thus protects against corrosion, even during long periods of inactivity. According to the project managers, over 90 per cent of existing engines are suitable for operation with E10.
Petrol stations
- Ultramarin in Kressbronn: HVO100 and Nautic E10 available
- Rudolf Bootservice in Bodman: In preparation
- Bodenseenautic buses in Dettingen: In preparation
Scientific monitoring and transparency
The Karlsruhe Institute of Technology (KIT) is providing scientific support for the project and ensuring that the fuels are converted. A special feature of the project is the "Digital Fuel Twin" tool developed by Bosch. It precisely calculates the CO₂ savings for each refuelling and displays them directly on the receipt - a system that is unique in Europe. This provides environmentally conscious boat owners with transparent proof of their contribution to climate protection.
Regional pioneering role and outlook
With the "Climate-friendly Lake Constance" project, the state government of Baden-Württemberg is taking on a pioneering role in climate-friendly shipping within the International Lake Constance Conference. For the owners of private boats, the pilot project means that they can now make an active contribution to environmental protection on Lake Constance without any technical changes or changes in behaviour. Anyone who is unsure whether their engine is compatible with the fuels can seek advice from the specialised workshops around Lake Constance.
The project is the start of an environmentally friendly future for shipping on Lake Constance. An extension to Switzerland and Austria is already being planned, according to those responsible for the project. Ministerial Director Frieß from the Baden-Württemberg Ministry of Transport, Prof. Dr Hirth as Vice President of KIT and Dr Herrmann from the Ministry of Transport emphasised the importance of the project for the entire Lake Constance region at the launch event.
