Smart energy concepts and sustainable materials used on new and existing yachts, in order to minimize their impact on the environment and climate. Currently, fuels of the future and various sustainable materials are being researched.


Ethereal’s owner Bill Joy launched his project with a “charrette” – a three-day symposium at the shipyard’s facilities, attended by the world’s leading academics in all the disciplines that might conceivably have a bearing on his project. Ethereal was launched by Royal Huisman in 2008. The world’s first hybrid superyacht is noted for her pioneering propulsion system and for incorporating 400kWh of stored energy in her Li-ion battery bank.



Ethereal has since logged several hundred thousand miles traversing the oceans. She can be propelled by sail, by mechanical propulsion, or be powered by her stored energy source. In addition to the sailing systems and anchoring functions, her entire domestic load can draw its power from the same set of Li-ion batteries. Click here to learn more about Ethereal, the world’s first hybrid superyacht. Or use this link to find the article “On board with Bill Joy”.


Project 392 (Elfje) incorporates an iteration of the hybrid technology that was inspired by Ethereal. Whereas Ethereal’s ground-breaking hybrid system focuses on propulsion and power management, Elfje interprets “hybrid” as generating power via variable speed, variable output generators backed up by a Li-ion “peak shaving” power storage bank and energy management system.


Exciting high performance and exceptional fuel efficiency for project 403 (PHI). At the start of this motoryacht project, the shipyard team was well aware that the fresh challenges posed by PHI’s brief – not least keeping her displacement below 500GT – would need to be addressed within a highly robust and efficient innovative framework. With success: her naval architect, Perry van Oossanen, says of her energy consumption: “She is 30% more efficient than a traditional 500GT motor yacht.”


Project 404 is the next high-achiever in terms of low fuel consumption. Her twin, fixed pitch, pulling propellers for optimized efficiency are directly connected to permanent magnet motors. The units are part of the swing retractable, redundant electric azimuthing propulsion system. Backward retraction minimizes the impact on interior volume. This superyacht is able to motor in true silent – stealth mode – operation, using only her batteries, so that an early morning silent departure from a peaceful anchorage is possible. Project 404’s retractable propulsion and board system: winner of the Innovation Award and Eco Award at the Design & Innovation Awards 2024: link.


Some unique features of these retractable electric drive propulsion units: power level (500kW each) – minimized noise and vibrations level (flexible mounting, single gear between e-motor and propeller and no gear inside the hull) – unit can serve as underwater turbine, generating power for the systems and charging the batteries.  Read more in the article ‘What goes down, must come up!’ at this website: news > inhuis stories & updates [link]


Project 410 (85m / 280ft New World Sloop) is in the process of engineering. Remarkable not only for scale and style, but for her green heart, because she will be the most environmentally focused megayacht ever built. Self-generation of energy is just one of many examples behind that bold description. A huge 2-megawatt battery bank facilitates silent and fumeless propulsion. This ensures ultimate comfort with maximum redundancy and sustainability. Wherever the technology permits – or can be adapted to permit – Project 410 will be future-proofed.


Foftein (1999) and Juliet (1993) have been transformed as a result of a conversion from conventional to hybrid power generation. The work was carried out by Royal Huisman’s Huisfit (link opens in a new tab). Both yachts received the ultimate systems upgrade with leading-edge propulsion technology and power generation. The onboard experiences with the new hybrid propulsion and energy system following the conversion by Huisfit can be accessed via this link.


The propulsion system of project 405 manswers the owners’ request for an emergency ‘get home’ engine. This flexible “tribrid” system of project 405 (Nilaya) provides three ways to power the variable pitch propellor without a supplemental third engine or gearbox. Its battery pack allows the yacht to operate silently in no-carbon areas.