It may seem obvious now that the whole world is going electric: naturally, boats should too. But at the scale of a superyacht, it is no mean feat to achieve. First and foremost, these are luxurious playthings for wealthy and demanding owners, who will not accept any limitations due to technical shortcomings. Safety is also a critical factor here. A feature that reduces the yacht’s ability to manoeuvre, or its overall range, may also not be acceptable.
All this meant that there was a huge hurdle to overcome when engineer Michele Maggi first began looking at capable hybrid systems for superyachts in 2006. When he set up his first hybrid system e-Motion, he had to develop a whole suite of systems that would enable an electrical and a diesel propulsion system to operate side by side.
“Nothing was available in the market as products, so I had to start from scratch,” says Maggi. “There was not yet the technology to build a permanent-magnet electric motor, a small-size industrial inverter, or an electromagnetic clutch. I had to convince manufacturers to develop all of these.”
Hybrid successes so far…
The first notable success for Maggi was with the Long-Range 23 from Mochi Craft. In 2006, this high-sided coastal cruiser made a name for itself with its electric propulsion mode, which gave it several hours of operation. “As variable speed generators were not yet available, only two options of propulsion existed at the time: full electric or full diesel,” he remembers.
Despite the economic crisis that engulfed the world in 2008, he kept at it, deepening his R&D efforts to improve the product. “I realised it was not really in the interests of an engine or gearbox maker to develop the whole system,” Maggi says. “At the other end, the shipyards didn’t want to take responsibility for the whole system. So I had the idea to develop it myself. I became a system integrator to deliver the whole package.”
But it wasn’t until 2015 that the next big step forward came with the installation of a true diesel-electric e-Motion hybrid system on board a Sanlorenzo SL106. Boasting two 2,216hp MTU engines and a top speed of up to 28 knots, this sleek 31 metre is all about ‘la bella figura’. Fast, elegant and now electrically powered, too.
For Sanlorenzo, it was a real proof of concept. The evident success of the SL106 with a hybrid drive led the shipyard to install the same set-up on the smaller SL86 series, before rolling out the e-Motion system to its biggest superyacht-standard lines, which they too named E Motion in a nod to its hybrid power package. The 44 Alloy, 500 Exp and 62 Steel already offer the e-Motion option, which will also be available on the new 50 Alloy, 1000 Exp and 58 Steel later this year.
“The diesel/electric combination developed for yachting is one of the most interesting applications of the hybrid,” says Massimo Perotti, President and CEO of Sanlorenzo. “The synergy between the two power sources has inspired us to seek the right balance between energy saving and performance, between on-board comfort and an eco-technological approach.”
Today, the applications for e-Motion’s hybrid systems run from 50ft up 220ft. Italy’s Tankoa yard has climbed on board the trend with the launch if its award-winning 50 metre Bintador, which scooped a gong at the World Superyacht Awards in 2020. Her set-up ran to twin 895kW MTUs alongside two 300kW motors that are fed by 250kW variable-speed generators. It gives the yacht a range of 4,900 nautical miles in diesel-electric mode at 10.5 knots, or a top speed of 18 knots in power boost mode.
“If I build another yacht, I will build it with this system,” says the owner of Bintador, whose priority from the off was comfort. He was quickly persuaded that the hybrid options offered by e-Motion would generate less noise and vibration, and so it proved. “Cruising on Bintador is really pleasant; sometimes it’s hard to notice you are actually moving.”
It’s not just motor yachts that benefit from a hybrid drive system. Perini Navi’s new E-volution range of luxury sailboats has also been designed around e-Motion as part of a lightweight package. The first boat to hit the water is the 42 metre sloop-rigged version, which offers a 3,000 nautical mile range under power at a very respectable nine knots.
Perini Chairman and CEO Lamberto Tacoli pointed to the success of the new hybrid range, calling it the “perfect symbiosis of comfort and performance”. Impressively for a line of 40- to 60- metre sailing superyachts, the iconic builder has sold three of the boats already.
If you look at the direction of travel in automotive and now smaller boats, it is indisputable: electric yachting is on the way. “We tell all our customers that building a yacht in this way today, is building a yacht for the future,” Maggi says with a broad grin.
e-Motion has invested heavily in its relationships with the major battery builders and is launching a proprietary product at the end of the year. New chemistry is set to double the capacity of lithium batteries over the next three years, he insists. “That means that with only one tonne of batteries, you can have all the power you need! It’s already realistic to think about yachts that will go full-electric in the future.”
When that happens, the e-Motion system is ideally designed to benefit. Its electric motors can be stacked up on the same shaft, with two or three of its 240kW units providing more than enough power to replace the internal combustion engine in yachts up to around 220ft. And when hydrogen fuel becomes more widely available, it will be relatively simple to replace the diesel generators with a fuel cell. All without any redesigning of the technical spaces.
original article: www.boatinternational.com