Public transport on water: faster, greener, smarter

Over the course of a year, researchers and companies developed a simulation model for a new transport system where energy efficiency, flexibility, and resilience work together. Initial tests were conducted using a prototype vessel to collect data for the simulations.

The results show that some transports were more energy-efficient than cycling – and for some commuters, travel time could be reduced by up to 20 minutes per day.

’We’ve seen that our concept is more energy-efficient and resilient than we dared to hope. Simulations from Blekinge institute of technology show that the virtual bridge solution between Handelshamnen and NKT in Karlskrona significantly reduced travel time and cut energy demand by 95 percent, says Tobias Husberg, researcher and project manager at Cstrider.’

The project studied autonomous, electric passenger ferries that can be linked together and adapted to demand. Instead of further developing traditional diesel-powered ferries, the focus was on a scalable and modular system optimised for short urban water transport.

The project also analysed the entire energy ecosystem, from charging and battery storage on land to the use of fuel cells and integration with the power grid. The collaboration between Actrify, Blue world technologies, Affärsverken Karlskrona, and Blekinge institute of technology covered the entire value chain.

’What’s unique is that we brought together the entire chain from the power grid to technology providers and operators. Even though we hadn’t worked together before, the collaboration functioned like a well-coordinated team, says Tobias.’

Advanced simulation model at its core

A key deliverable of the project is an advanced simulation model that enables analysis of various energy configurations, traffic scenarios, and charging strategies – including how the system responds to disruptions. The model can handle both battery operation and fuel cells, and the combination of batteries with methanol-powered fuel cells is particularly interesting.

’With the same weight as a battery pack that lasts one day, we can run for a week on methanol. This provides high resilience and makes the system less sensitive to power outages, Tobias explains.’

Resilience in times of crisis

The project addresses not only everyday sustainability but also preparedness for societal crises. As transport systems become more electrified, vulnerability to power supply disruptions increases. Therefore, researchers studied how the system could operate off-grid using electro fuels and onboard energy converters.

This type of flexibility enhances resilience during power outages and crisis situations while supporting the transition to a more decentralised, renewable energy system.

Next step – from simulation to reality

Beyond climate benefits and energy efficiency, the system can ease pressure on existing infrastructure, reduce travel times, and improve accessibility in urban environments with waterways – an often-under utilised resource. For many cities, this offers an opportunity to rethink mobility and urban planning.

The project is now formally completed, but the work continues. The results have attracted attention in both local media and research networks, and new research avenues are being planned. The hope is that the project can pave the way for new solutions in Swedish and international cities – and inspire a new way of thinking about sustainable mobility.

About the project

The project Resilience in electric & charging Systems – challenges and opportunities with marine public transport received funding from the Swedish energy agency’s research program Sustainable transport systems and ran from 1 April 2024 to 31 March 2025.

About sustainable transport systems

The Swedish energy agency’s research program Sustainable transport systems started in 2023 and will run until 2029 with a total budget of SEK 305 million. The goal is to accelerate the transition to a fossil-free, transport-efficient, and resource-efficient transport system.