Wattlab Powers First Solar-Hybrid Inland Cargo Vessel
July 8, 2025 – By Dom Magli
In a pioneering development for sustainable maritime transport, Dutch maritime solar technology company Wattlab has successfully delivered and installed a solar energy system on HGK Shipping’s inland cargo vessel, Blue Marlin. This marks the Blue Marlin as the world’s first inland ship to utilize solar power for hybrid propulsion, setting a new standard in green shipping technologies.
Trailblazing Solar Integration for Propulsion
The solar hybrid system features 192 solar panels installed on the Blue Marlin, which provide electricity not only to standard onboard systems but—crucially—also to the ship’s high-voltage propulsion network. This integration allows solar energy to directly assist in powering the vessel’s propulsion, a first in inland shipping. The system can deliver up to 35 kilowatts and is designed to work seamlessly alongside four diesel generators through an automated energy management setup.
This hybrid configuration supports “peak shaving” — a method of balancing the power load to reduce the need for additional generators during periods of high energy demand — thereby enhancing fuel efficiency and reducing emissions.
David Kester, Co-Founder and COO of Wattlab, explained the significance: “The Blue Marlin’s 192 solar panels are connected to both the low-voltage onboard systems and the high-voltage propulsion network. This means that HGK Shipping can proudly claim to be the first inland shipping company operating a vessel powered directly by solar energy for propulsion.”
Evolving from Past Successes
The Blue Marlin builds on HGK Shipping’s sustainability efforts following their previous project, the MS Helios. Launched in 2024, the Helios made headlines by entering the Guinness Book of Records for hosting the largest solar panel installation on an inland vessel at the time, with 312 solar panels. However, unlike the Helios, which powered only low-voltage systems, the Blue Marlin’s solar system is fully integrated with the vessel’s propulsion mechanism, marking a significant technical advancement.
Tim Gödde, Director of Ship Management at HGK Ship Management Lux S.à r.l., highlighted the environmental benefits: “The Blue Marlin takes a vital step forward by using solar energy for the power train itself. Shipping is already recognized as a low-emission transport mode, but this development makes it even more sustainable.”
Collaborative Installation and Industry Implications
The solar system installation was carried out at the De Gerlien van Tiem shipyard, with Wattlab collaborating closely with specialist partners Blommaert Aluminium and Van Tiem Electro to realize this innovative project.
Wattlab views the Blue Marlin as emblematic of a broader shift underway in maritime energy strategies worldwide. As environmental regulations grow stricter and fuel market volatility persists, shipowners are increasingly turning towards solar and hybrid energy solutions not only for inland vessels but also for coastal and seagoing fleets.
In line with this vision, Wattlab launched SolarDeck in April 2025—a modular and scalable deck-mounted solar panel system aimed specifically at the seagoing shipping industry to significantly reduce fuel consumption and carbon dioxide emissions.
About Wattlab: Wattlab is a Dutch maritime solar technology company focused on integrating solar power systems with vessel propulsion to enhance sustainability in shipping.
About HGK Shipping: HGK Shipping is a shipping company engaged in inland waterway transport, actively pioneering renewable energy applications in maritime operations.
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