Wattlab is launching SolarDeck, a modular system of deck-mounted solar panels designed for seagoing cargo vessels. The system reduces fuel consumption and CO₂ emissions, with an expected return on investment of 3 to 5 years. It has been tested in real conditions, in a project run together with TNO and Vertom, co-financed by the European Union’s Just Transition Fund.

Wattlab started in 2017 with a focus on inland shipping, installing Solar Flatrack systems on more than 25 vessels. The move into seagoing shipping is a natural next step. The challenge was adapting the technology to a tougher environment: saltwater, rougher sea states, and different operational demands.

“At all times during the design of SolarDeck, we prioritised the shipowner’s requirements,” says CEO Bo Salet. “We know that time is money. That’s why SolarDeck can be installed quickly using container twist lock fittings, without impacting normal loading and unloading. And if the deck is needed for cargo, like offshore wind blades, the crew can store the entire system inside the volume of a 20-foot container.”

Tested with TNO and Vertom

SolarDeck was developed and tested over 18 months on board Vertom’s 7,280 DWT general cargo vessel Anette. TNO validated the performance results. The findings were clear: the system generates the expected power output, holds up against storms, and keeps working through the day-to-day activities of a working cargo ship.

SolarDeck on Vertom’s MV Anette during the test phase.

“The test results show that SolarDeck performs well in the tougher coastal shipping environment,” Salet explains. “Because salt water drains freely from the panels, there is no salt crust forming that would reduce power output. The system is also robust enough to handle storms and regular deck work, while staying safe at all times.”

What it means for shipowners

The numbers speak for themselves. But beyond the business case, SolarDeck is also a practical answer to regulations that are only getting stricter. Shipowners looking for a way to improve their scores without a major refit now have a real option.

Bo Salet is confident about what comes next. “We are excited to introduce SolarDeck to the seagoing shipping industry and to show shipowners what this system can do for their operations.”

The JTF funding that supported the pilot was provided under the EU’s Cohesion Policy 2021-2027, as part of the Just Transition Mechanism working toward EU climate neutrality by 2050.