Sunreef Yachts builds luxury sail and power catamarans in its boatyard in Poland and has been doing so for many years. We were intrigued to learn via press release recently that the Catamaran Company, a U.S. dealership and brokerage, had sold a U.S. buyer on an 80 Sunreef Power Eco version—”an ultramodern electric catamaran with 1mm ‘solar skin’ integrated with the hull and bodywork.” The release describes electric motors, a powerful battery bank, and super-efficient climate control, among other things.
We contacted CEO Staley Weidman to learn more about what “eco” stands for, and why a client with the means to buy any 80-footer would choose this one. Weidman has sold more than 700 cruising catamarans in his career and described this client as being part of a lifelong boating family with a history of New England cruising aboard Broward and other motor-yachts of 100 feet and larger. That may sound traditional, but the family has a demonstrated interest in cutting-edge technology and is not afraid to buy the first in a series; they were early investors in Tesla and have implemented solar power on all of their commercial buildings and homes.
The new factory at Sunreef Yachts in Gdansk, Poland, has easy access to the water as demonstrated by this Power 60 undergoing sea trials before delivery to Florida.Representing his client, Weidman said he started looking at four manufacturers of eco-hybrid cruising cats and ended up focusing on Sunreef Yachts, which has a modern facility in Gdansk. None of the systems on the boat are new to Sunreef, but the company has never put them all together before at this level.
Staley Weidman, CEO of The Catamaran CompanyBefore describing some of them, it’s worth remembering that an 80-foot cat like this is 39 feet wide. (See plans below.) It can accommodate 12 people plus a crew of four, and while it’s equipped with advanced technology in its solar, battery, electric motors, air conditioning, heat pump and more, it also has two large diesel-powered generators and a diesel fuel capacity of over 4,000 gallons. That’s what makes it a diesel/electric hybrid.
The Power Eco is almost as wide (39′) as it is long (80′) and features four spacious gathering areas—foredeck, flybridge, aft cockpit and main saloon—plus a full-width aft platform and tender garage. Four cabins including master, plus crew cabins can easily be accommodated by the two hulls. Battery banks and other equipment are unobtrusive. (Note each layout is customized to the buyer’s specifications.)
Operating in southern New England in the summer, the boat will be able to run at 14 knots for 22 miles on batteries alone, making a trip along the coast to the islands feasible without generators. If the batteries run low and the generators are employed, the boat’s range goes up to 1900 miles, but Weidman says this owner is likely to need only a fraction of that fuel when typically cruising. In the winter months, it will be based in the Virgin Islands, chartering—once again with short daily runs in silence.
What’s more impressive, though, is that the boat’s 750kW battery capacity combined with super-efficient A/C units will allow the AC to be run all night without kicking on a generator. In-fact, all the electrical systems on the yacht can operate up to 4 days without the need to regenerate any power into the battery banks. The A/C system has been designed with small air handlers in different areas of the boat, cooling by a super-efficient variable-speed centrally located compressor bank. The system is powered by high-voltage DC from the boat’s battery bank and managed by a climate-control computer software that conserves power whenever possible. Much of the efficiency is derived by eliminating the traditional chilled water circulation system used in most yachts of this size. According to Sunreef, the system consumes 70% less energy than is the norm in the industry.
Battery technology is advancing rapidly in marine applications, and this yacht will have an air-cooled 750kW battery bank designed exclusively for marine applications. It will use Li-NMC cells (Lithium Ion Nickel Manganese Cobalt), which are said to provide more power with lighter weight, smaller size and 25 percent more range than last year’s LiFePo4 (Lithium Ion Iron Phosphate) chemistry. The power density (weight to power ratio) of the batteries is below 13.64 pounds (6.2 kg) per kWh. Sunreef says that their Eco batteries are now close to 30 percent lighter than the average lithium-ion systems commonly used on other yachts.
Sunreef’s proprietary technology includes super-thin solar membranes used in the new ECO line.
The solar power cells arrayed across the boat’s deck, hulls, and superstructure are also unique, extremely durable, 1mm thickness cells, and are applied in a proprietary manner. Weidman says, “You wouldn’t feel the cell on the hull if you had your eyes shut.” He says that the small sizes of the cells with individual controllers increase the flexibility Sunreef has in maximizing and optimizing placement and therefore output of each cell.
The boat is scheduled for delivery in the fall of 2022 and should be in North America a year later on display at the 2023 Ft. Lauderdale International Boat Show. Weidman’s Catamaran Company plans to produce a 10-part documentary film allowing us to follow along with the story of the development of this yacht’s construction between now and then.
Weidman wouldn’t tell us the retail price for the 80 Sunreef Power Eco, but he shared that conventional sailing versions cost in the range of $7 million and that this will come at a premium level on top of that. He added an interesting reflection:
“I had my doubts on how this yacht would be ultimately conceived. I thought we would do a lot of evaluation, talk to builders, get educated on the technology, and come away with the conclusion this isn’t for us and we should go more conventional.
“After exhaustive evaluations of builders and yards, I’ve learned tons and seen the strong points of each builder. But the main thing I realized is that an Eco-type yacht is here; it’s possible to do, if a bit expensive, but you can ask any boater in the world if they’d like to run their boat for four days without turning on a generator and get the same answer. This technology has a lot of appeal. Every day, I see things about plant-based food and renewable energy, and I’m seeing it applied daily, and it’s the wave of the future.”