Sunreef is a point of reference in the multihull world. During the past 20 years, it has earned a solid reputation for building high-end luxury catamarans, sail and power. But eco-responsible cruising is now high on the list of priorities for owners, and boatbuilders are under pressure to respond.
Enter the nearly 80-foot (23.9-meter) Sunreef 80 Eco, a yacht that combines luxury with sustainability in what Sunreef calls a “green breakthrough.”
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Sunreef
The first hull is owned by brand founder Francis Lapp. Marie-Joseph is a yacht that, at low speed, can run virtually indefinitely on renewable energy from sun, water and wind with electric propulsion and smart energy management. Completely new, for example, are ultralight solar panels that have been integrated into the composite hulls, the superstructure and the mast, using a patented system engineered in-house.
Apart from the hydraulic stern platform, everything on board, from the bow thruster to the headsail furler, is electric.
“A few years ago, we set up an R&D team to find out how we could integrate the solar panels into the actual structure of the yacht without compromising the design,” says Nicolas Lapp, vice president of Sunreef and the son of its founder. “On top of that, they had to be very light and strong. In fact, we wanted them to be as strong as the rest of the hull, and the first test was banging them with a hammer.
All we did was scratch the paint.”
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Sunreef
The photovoltaic system has a peak power output of over 45.5 kW per hour, and propulsion comes from twin 160 kW electric motors. Energy can be stored in a 550 kW lithium-ion battery bank for propulsion and to power the hotel loads. Under sail, the Sunreef 80 Eco recovers energy from the passive rotation of her two propellers via a hydro-generation system able to produce more than 15 kWh when sailing faster than 7 knots.
The goal of the design is not just about reducing fuel consumption and emissions. E-motoring actually feels more like sailing because the electric motors are virtually silent—no noise, no vibration and no engine fumes, whether underway or at anchor.
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Sunreef
For many boaters, the big draw of catamarans is the massive social space they offer on the main deck, inside and out. Monohulls can’t compete with the size of the open-plan main salon and its wraparound panoramic windows.
The layout is flexible. In this case, Fracis Lapp chose two large facing sofas, a hi-lo central dining table, a bar area forward and a piano. Celebrity customers such as tennis player Rafael Nadal and racing driver Nico Rosberg chose slightly different solutions. The luxury materials and quality finish throughout are consistent with Sunreef’s high standards.
Hull layouts are also modular. On the first unit, the after end of the portside hull is taken up by a professional-spec galley with a VIP suite and the owner’s stateroom forward. The starboard hull houses two ensuite guest staterooms and a crew cabin. The service area and guest accommodations are served by separate companionways.
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Sunreef
Aft, the cockpit is set up for alfresco dining, while the foredeck has a sunken dinette in addition to the trampolines spanning the two hulls. Excellent visibility from the flybridge makes it the place of choice for driving the boat in all but the hottest or most inclement weather.
The first unit also has more lounging space, outdoor cooking equipment and treadmills up top. It’s just a shame that the latter two consume electricity rather than produce it.
Sunreef’s pursuit of eco-tech continues inside with the HVAC system. Air conditioning is one of the biggest consumers aboard any yacht, so the yard installed a system that, in terms of weight, size and consumption, is reportedly one of the most advanced available.
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Sunreef
“After researching the production of energy, we then looked into how to save energy on board,” says Nicolas Lapp. “We started with the air-con, the biggest consumer, and developed a system with titanium parts for much better efficiency. Compared with other top products on the market, ours is at least 30 percent more efficient.”
The rapid pace of technological development means Sunreef has already upgraded the batteries that were installed on Marie-Joseph. The brand has also sold an 80-foot sailing cat that will be equipped with a fuel cell that produces electricity from hydrogen harvested from seawater by electrolysis. Hull No. 1 of the 80 Eco Power was set to premiere at the Fort Lauderdale International Boat Show.
For more information: sunreef-yachts-eco.com
SUNREEF 80 ECO
LOA: 78ft. 4in. (23.87m)
Beam: 37ft. 10in. (11.53m)
Solar panels: 186sqm./34kWp
Engines: 2x 160kW
Battery bank: 550kW
This article was originally published in the Winter 2023 issue.