Speed, energy capacity and cruising efficiency are impacted by a number of factors, explains Faiss. “The configuration entirely depends on what the client has in mind. Hull number one of the Solar 62 will have two 60kW engines for peak consumption and two 44kW for continuous support,” he says. The Solar 62 will be able to run self-sufficiently, even to a limited degree at night. On a usual sunny day, while underway, batteries will charge for evening use and not deplete when cruising at six to eight knots. Solar 62 requires no combustion engine, however, she is available with a diesel hybrid system for owners who do not wish to be limited by conservative speeds. To date, two zero emission Solar 62s have been sold and one hybrid version.
Unfortunately, at least for the time being, it is unlikely that superyachts will be able to follow this self-sustaining yacht model. “The problem with larger vessels, of course, is weight,” continues Faiss. “Weight increases massively towards 30m, that is why there are no superyachts at the moment running independently.” However, while we wait for battery technologies to improve there is no reason why we cannot develop a number of the systems that will greatly increase the chances of independent superyachts in the near future.
“The secret to good electrical performance is weight,” Faiss reiterates. “On the Solar 62 we have an approximate empty weight of 18 tons, the comparable Lagoon 62 is 46 tons.” Faiss maintains that the Solar 62 is equally as stable as her meaty predecessors. “The catamaran is a very stable construction in general and 18 tons is still heavy.”
The main weight loss is affected within the hull thanks to its epoxy resin construction. Nedship worked closely with A.R.C Yachts Antalaya and Dr. Orhan Celikkol to get the best out of this epoxy brief. But, what is most unique about the Solar 62 is that much of the furniture on board has been incorporated into the construction of the vessel itself.
“Most of the furniture on board is part of the structure. We are using the structure in such a way that we don’t have to put a second wall somewhere, the draws and so on are part of the wall,” explains Faiss. This integration of on board furniture is a technique that Nedship will be continuing on its 25m project that is currently in discussion. Epoxy resin is already widely in use for superyachts in the smaller 30-40m range, have the limitations of weight reduction yet been reached? Weight has also been saved on the Solar 62 by carefully selecting on board items such as fridges partially according to their weight and producing honeycomb furniture.
And what of increasing energy efficiency? That advent of zero emission yachts will undoubtedly bring with it a whole host of unique innovations to this end. On the Solar 62 Nedship has incorporated a retractable sunroof. When guests wish to use the sundeck a large portion of the solar panel folds out to reveal a relaxing outdoor area. However, this raising of the panels means that other panels will be cast in shadow. Being able to retract the roof ensures that when the sundeck is not in use the solar panelling is operating at maximum efficiency as well as protecting the sundeck from adverse weather conditions.
Nedship’s 25m project will feature retractable solar panel wings that will almost double the amount of light that the vessel can absorb and convert into energy. However, Faiss stresses that all current plans for larger yachts incorporate a hybrid system that will allow the owner to run electrically or by diesel. The current concept relies on the use of two separate propeller systems due to the large variation in speed ranges produced by either system. Nedship is currently playing with the idea of a retractable electric propeller.