
Enviu and its partners broke the chicken-and-egg conundrum in the maritime sector. But, more needs to be done.
This is the year that passengers boarded the world’s first hydrogen-fueled water taxi. The water taxi, which was officially launched on August 30 in Rotterdam, makes the case for hydrogen as a fuel. More importantly, it demonstrates that a zero-emission maritime future isn’t just ambitious, but possible.
One ship at a time
With the water taxi, Enviu is showcasing a commercially ready, emission-free solution for passenger transport by water, which can be scaled up for larger ships in the maritime sector. However, challenging the status quo in a sector as traditional and siloed as the maritime sector demands intensive collaboration. Greenhouse gas emissions, and the resulting global warming, are one of the biggest problems we are facing as a society today. If the maritime industry were a country, it would be among the top six producers of greenhouse gas emissions globally. Waterborne transport accounts for more than 3% of global emissions, and 10% of all transport emissions. Needless to say, change is needed.
At Enviu, we have seen in other sectors that we can drive this kind of large-scale transition by starting with something small and concrete.

The technology challenge
It took a dream team of partners to make this “lighthouse venture” a reality. Together with Flying Fish and Zepp.solutions, we co-founded SWIM with one mission: to develop hydrogen-electric propulsion systems that show the way for other developments in zero-emission sailing.
“In the automotive industry, we have been working on hydrogen powertrains for a long time,” says Jonas Brendelberger, one of the founders of Zepp.solutions, which is responsible for the hydrogen fuel cell system in the water taxi. Their fuel cell systems are already used in trucks and excavators. “This is our first boat,” he says.
One of the biggest advantages of a hydrogen-electric boat is that it can be refueled within minutes, as opposed to battery-electric boats that often take hours to recharge.
Gijsbert van Marrewijk, a co-founder of Flying Fish, proudly opens some panels in the cabin to show the technical highlights of the hydrogen-powered boat. Flying Fish is responsible for the boat’s electric powertrain.
“This is the cooling system,” Gijsbert says, pointing to a tangle of hoses and dials. Under yet another panel is the power distribution unit designed by Flying Fish. This distributes 750 volts to the engine, battery, and onboard network. This will ensure that the boat is completely safe.
Meanwhile, in the front of the boat, someone else is busy connecting wires from the safety systems under the ‘bonnet’ to the dashboard in the wheelhouse. Marrewijk and his team alternately work on the boat and in the workshop in Delft to test the system.

and Enviu’s Maarten Fonteijn, Thea van Unen and Daniël Moolenburgh.
The infrastructure challenge
Finding partners who can provide the hydrogen infrastructure is as important as testing the system, Maarten points out.
The Port of Rotterdam has floated a concession tender for a Green Energy Refueling Station (GERS). In collaboration with the Port of Rotterdam, Enviu identified the economic, technical, and impact potential of GERS. GERS will be developed in the RDM Dokhaven. The dokhaven (dock harbor) is the centerpiece of the innovation cluster in Rotterdam, strategically located to refuel our SWIM hydrogen water taxi daily.
The ‘scaling up’ challenge
In the end, the main challenge is actually not the technology or infrastructure; it will take time, but it will come. The biggest challenge is actually scaling up.
The need of the hour is more applications to make new technologies competitive. Diesel is extremely cheap and compact. It is a tough competitor if the new technology does not have the right scalability and/or rewards. Also, both regulators and passengers are quite unfamiliar with hydrogen as a fuel, leading to questions about safety and uncertainty regarding regulatory requirements.
“We need pioneers to show them how it can work. And we need pioneers to break through the stalemate situation of costs and scale. We need scale to bring the costs down, and we need lower costs to bring scale,” says Maarten Fonteijn, Enviu venture builder.
This is what the SWIM team has been working on. Using the water taxi as a well-defined case, together with the Port of Rotterdam, the team is investigating how the safety requirements will have to be adapted. Once we know that, we can look into regulations for other ships, adds Maarten.
All hands on deck
If the water taxi project with the prototype of SWIM’s hydrogen-electric powertrain shows us one thing, it’s that we cannot do this alone.
This lesson is at the heart of everything we do under Thrust. The partners we bring together are vital to the success of our ventures and projects — technical partners to develop innovative solutions; public and private partners to enable their working; and funders to fuel the change.
With the hydrogen-electric water taxi, we broke through ‘the chicken or egg’ problem of supply and demand for a new fuel like hydrogen. That is only possible because of our partners, who share both our vision of a zero carbon footprint maritime sector and a bold and entrepreneurial mindset. And so, by collaborating on one small boat, we have taken a big step towards our common goal.
This article was published in Enviu Impact Magazine 2022.
