Innovating for impact: Sunreef’s blueprint for sustainable yachting

Sustainability or eco-friendliness are not the first things most people associate with luxury yachting. Yet there is a clear trend towards “greener” yachts, says Artur Połoczański, Public Relations Director at Sunreef Yachts. The approach of his company to this idea leads through comprehensive research and development, he stresses.

Catamarans are energy-efficient

“If you go to any superyacht show worldwide, you’ll notice a dominance of big-displacement, fuel-guzzling monohull motor yacht designs. We’re in the midst of changing that perception,” says Połoczański. “We started out over 20 years ago by opening a new market niche: the luxury catamaran.” Catamarans have many advantages, from high stability to low friction in water, resulting in a substantial reduction of the energy required to move the craft. Multihull yachts are rapidly gaining in popularity because of these properties.

Sunreef, based in Gdansk, Poland, is propelling multihulls into the mainstream of yacht building. “Sunreef injected the idea of high quality into the catamaran,” says Połoczański. “But we didn’t stop there. We’ve been reinventing that product, changing the idea behind what a luxury yacht is.”

Electric and solar yachts gain traction at Sunreef

Sunreef builds both motor and sailing yachts in sizes from 45 ft (13.72 m) up to a 210 ft (64 m) trimaran superyacht. Every model is available in a “classic” or “eco” version, and with conventional combustion-engine, hybrid or pure electric propulsion. It is the “eco” range where Sunreef focuses most of its R&D efforts. “Today, roughly 50 per cent of enquiries are for eco models with features such as electric propulsion, batteries and solar panels,” explains Połoczański. The sailing versions have the smallest potential ecological footprint.

“I think this trend will continue to grow, because the younger generation tends to be more environmentally conscious,” says Połoczański. “But even with the current generation of yacht owners, we can see that trend. Going eco is convenient to them: they save money on fuel and maintenance because electric motors are easier to maintain; they can navigate in silence and without vibration and fumes, so an eco-yacht benefits both the environment and the owner. It isn’t difficult to convince customers of these benefits.”

DNV helps maintain the focus on quality and sustainable innovation

DNV has assisted Sunreef in implementing its innovative technical solutions, helping the company ensure its products comply with the environmental regulations applicable to large yachts. “From the early design stage, Sunreef has been able to rely on DNV’s assessments as to whether the proposed innovative solutions will meet safety requirements,” Połoczański highlights.

Class-related DNV services include the voluntary class notations Clean (Tier III) and Battery (Power) for Sunreef’s yacht designs. “Sunreef’s choice of these class notations represents an investment not only in environment protection and sustainability but also in performance, marketability and long-term regulatory compliance. Whilst this requires careful planning and technical evaluation, the final product is a yacht that reflects the contemporary values of responsibility, innovation and environmental stewardship,” DNV Project Manager Piotr Jetke points out. Artur Połoczański adds: “DNV plays an important role here, providing comprehensive inspection and approval of the work and covering everything from composite work to electrical systems.”

As an acknowledged leader in rig certification, DNV has also been entrusted with assuring the rigs for three Sunreef catamaran units, an ongoing process that is expected to be finalized by the end of 2025 alongside hull classification.

Sunreef integrates solar, wind and fuel cells for clean cruising

Technology is the driver of sustainable yacht building at Sunreef. “The most recognizable feature of our boats is our solar panels, which we call ‘solar skin’, an industry first,” describes Połoczański. “They’re integrated into the composite hull material, giving us more surface area.” The battery banks are engineered specifically for Sunreef, and customized to fit the specific model.

Air conditioning is the biggest energy consumer on board a luxury yacht, which is why Sunreef has had its supplier develop an extremely energy-efficient technology made with lightweight titanium parts and using gaseous rather than liquid coolant.

Optional wind turbines provide an additional energy source. Furthermore, the sailing superyachts, especially the popular new 43M model, can be equipped with hydrogenerators that generate electricity by letting the water flow turn the propellers backwards whilst sailing. The company is also developing methanol-powered fuel-cell systems for electricity generation, as well as dual-fuel generators that will benefit from the evolving alternative fuels infrastructure.

Recycled PET foam reduces weight and emissions

A lighter craft requires less propulsion energy, whether diesel or solar. Therefore, the engineers at Sunreef develop alternative structural materials. “We use a lot of lightweight PET foam in our hulls that’s made from recycled PET plastic bottles,” says Połoczański. “For example, the Sunreef 80 incorporates material from around 600,000 bottles.” The same material can be used for some of the interior furnishings, as well, he adds: “We’re now replacing plywood. In a Sunreef 80, for example, this is equivalent to an additional 180,000 recycled plastic bottles.”

Renewable raw materials help protect rainforests

Concerns of rainforest destruction have spurred a public discussion about the use of teakwood in the marine world, prompting Sunreef to look for a substitute. “We’re now replacing teak with a natural alternative,” says Połoczański. “In a few months, we’ll launch a first boat with this alternative decking solution, and from that time on all of the Sunreefs will use that instead of teak. I believe that the alternative we found is perfect.”

Similarly, a plant-based alternative for glass or carbon fibres in composite elements has been found: Flax. Grown in Normandy, France, this low-cost, easy-to-grow plant requires little water and has a negative CO₂ footprint. “Our flax fibre composite is fairly close to the conventional one in terms of physical properties, such as strength,” Połoczański points out. “On some Sunreefs you can already find bar modules, navigation stations and tables made with flax fibres; we can make Jacuzzis and ceilings from this material and are about to introduce it to structural elements.”

Establishing end-of-life recycling and repurposed décor

Simultaneously, the R&D department is following the advancements in energy-efficient, eco-friendly recycling technologies closely. “More and more resin systems are invented specifically for easy fibre-resin separation after end-of-life. We believe that in the near future there’ll be mature systems we can use as a standard solution,” Połoczański is confident.

Repurposing or selling used material is part of the sustainability strategy at Sunreef. The yard separates all waste for re-use by other industries. “Our waste is properly recycled and reused whenever possible,” Połoczański adds.

Interior decoration lends itself to the use of recycled or recyclable materials. Sunreef leaves the decision up to the customer: “Our customers can touch and feel samples at our showroom to see for themselves that there are no compromises in terms of luxury when they use recycled material, whether rugs made from recycled plastics, furnishings from repurposed teak or countertops made out of recycled cardboard and paper,” describes Połoczański.

Artificial intelligence can boost energy-efficiency

There are various R&D areas at Sunreef where AI is helping to enhance sustainability. In the latest iteration of the Sunreef Solar Skin system, machine learning algorithms and historical data from the Sunreef Eco catamaran fleet optimize the solar panel placement on the yacht to maximize energy generation in varied sunlight angles.

AI is also key to sailing automation, says Połoczański: “Yacht charterers often avoid sailing because they consider it as a hassle, and are happy motoring instead. We want to make sailing easier by applying smart algorithms and AI to minimize energy consumption.”

To minimize the effect of shadows cast by the sails on photovoltaic surfaces, AI can optimize the heading of the craft and the sail position. “We expect AI-based intelligent energy management systems to learn from crew behaviour and optimize the overall energy efficiency of the yacht in the near future,” says Połoczański.

The goal: Building boats that last generations

Product longevity is a key aspect of sustainability, Połoczański points out. “We want to build boats that last generations,” he says, confident that the Sunreef philosophy will be there for the long term. “This is one of the future trends. Superyachts can be energy-efficient. That’s, in a nutshell, the vision for the future of Sunreef.”