Image:Wattlab
From Canals to Cargo Ships: Wattlab Expands Its Maritime Footprint
Wattlab, the Dutch solar energy start-up known for bringing solar power to inland shipping, is setting its sights on the high seas. The company, founded in 2017, has gained traction in the inland waterways with its modular Solar Flatrack and SolarHatches, which are already operational on more than 25 vessels. But now, Wattlab is charting new waters—literally.
Its latest innovation, SolarDeck, has just completed its first pilot project on a seagoing vessel. Partnering with the Dutch Organisation for Applied Scientific Research (TNO) and international shipping firm Vertom, the pilot was co-funded by the EU’s Just Transition Fund, aimed at achieving climate neutrality by 2050.
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Proving It Works at Sea
The SolarDeck system was installed on Vertom’s 7,280 dwt general cargo vessel Anette. According to Bo Salet, Wattlab’s founder and CEO, the aim was twofold: test the power output and validate structural integrity in the tougher maritime environment. TNO was brought in to evaluate solar generation performance, while the ship itself served as the ultimate stress test.
And the results? Promising. “We recently heard back from TNO that the SolarDeck’s power output is in line with expectations,” said Bo Salet. That’s no small win, considering the challenges at sea—salt spray, harsh weather, and constant motion. “Saltwater can drain freely from the panels, meaning no salt crust builds up, which usually reduces power efficiency,” he added.
The Anette encountered some heavy storms during the trial, but the system held strong. Though there are some design tweaks ahead, no damage was recorded. And importantly, any future damage can be repaired easily by the crew, minimizing downtime and cost.
Safe by Design
One key concern for any shipowner? Safety. SolarDeck checks that box too. Using a stand-alone solar system similar to their inland configuration, the panels are designed to shut down automatically in the event of cable damage—no live current, no hazard.
And how about durability on deck? According to Salet, the crew went about their daily routines—rinsing with fresh water, soap, even heavy-duty acidic descaling liquids—with no adverse effects on the SolarDeck. “We specifically asked the Anette’s crew to carry on their usual cleaning activities,” he explained. The result? The system kept on working, unfazed.
Image:Wattlab
Making Room for Solar on a Busy Deck
Cargo ships aren’t exactly short on deck traffic, and with loading and unloading constantly underway, how does SolarDeck fit into the workflow? Salet insists it’s been designed with flexibility in mind.
“The SolarDeck can stay in place during loading and unloading because it’s thin enough to fit between two stacked hatches,” he said. Disconnecting cables only takes two minutes per edge. And if a ship’s job requires a full deck—say for wind turbine blades—the SolarDeck modules, built to container twist-lock standards, can be manually removed and stacked into the volume of a 20-foot container.
It’s as close to plug-and-play as it gets at sea.
Automation Eases the Burden on Crew
Managing power output may sound complex, but SolarDeck handles it on autopilot. “The generators will turn off when they’re not needed,” said Salet. If there’s too much solar power, the panels automatically shut down to prevent overload. No need for crew to monitor anything actively.
For an industry increasingly focused on emissions compliance and operational efficiency, that’s one less thing to worry about.
Regulatory Benefits and ROI
Now, let’s talk numbers. Wattlab estimates a 30 MT reduction in fuel use and 96 MT fewer CO2 emissions annually from a full SolarDeck installation. For shipowners trying to boost their EXI and CII scores—or just reduce compliance costs under FuelEU Maritime and EU ETS—those are hard figures to ignore.
In terms of return on investment, the outlook is conservative yet attractive. Wattlab expects a payback period of four to five years, excluding potential subsidies. Interestingly, older vessels—often with less efficient generators—stand to benefit the most.
And because SolarDeck systems are not permanently installed, they can be removed and reused on other vessels. That mobility could be a game-changer for shipowners looking to upgrade incrementally rather than overhaul their entire fleet.
Scaling Up: Full Deck Ahead
With the pilot deemed a success, Wattlab is now preparing for its first full-deck installation before summer, again with Vertom. Covering an entire cargo ship’s deck with solar panels might soon go from futuristic concept to practical reality.
As solar technology steadily gains a foothold in seagoing shipping, it seems Wattlab is steering into uncharted waters with confidence—and solid data to back it up.
