Silent Yachts: 500 lithium battery packs, 2.5 megawatts on order

With 10 solar electric catamarans under construction, these lithium battery packs have energy storage equal to about 25 Tesla Model S EVs.

If you ever encounter anyone who has doubts about the future of electric boats and boating, you can point them to Silent-Yachts, the Austrian solar catamaran pioneer which sold their first solar cat in 2018 and now have 11 electric yachts in the water with another 20 being built for delivery in 2021.

To meet demand, Silent-Yachts has new shipyards in Thailand and Italy. The Asian yard, about 220 km from Bangkok, is led by Swiss entrepreneur Philippe Guénat and is the largest privately-owned shipyard in South East Asia. In Fano, Italy, a series of Silent 60s are now under construction and a second line is being set up to provide capacity for building 15 Silent 60s a year.

The first delivery is in January and will be the first Silent-Yacht equipped with their new automatic kite sail system. The kite flies between 70m and 140m above the yacht and can generate up to 10 times more power per square meter than a conventional sail. It is mounted on the front deck and stored in a dedicated compartment below the front deck when not in use.

In addition to the Silent 60s, there is also one Silent 55 under construction and 4 of the new Silent 80s. Hence the need to order all of these batteries!

Lithium battery packs in catamaran hulls

Altogether the batteries add up to 2.5 megawatt hours of energy, roughly enough to run 3 average US homes for a month. They are lithium-ion chemistry from MG Energy, a Dutch company started by two former Monaco Solar & Energy Boat Challenge winners. MS also provides the energy storage for the PowerCat 3400 by New Zealand’s Herley Boats.

Lithium battery packs are in each hull, as shown in this diagramThe battery modules and motors are housed in each of the catamaran hulls and provide the energy for propulsion and all of the amenities like air conditioning, water maker and kitchen appliances including an electric stove with induction cooktop.  The motors, inverters and their cables are IP69 certified and the system is certified to DIN EN ISO standards for marine operations of electrically powered yachts.

The whole Silent-Yachts story is indicative of electric boats and electric boating in general. Founders Michael & Heike Köhler started working on their first ocean going solar boat, SOLARWAVE 46, in 2005. Launched in 2009, in 2010 they took it on a four year sea trail that took them through rivers all over Europe, the Black Sea, the Aegean and the entire Mediterranean.

For some perspective on how things have changed since then, lithium-ion batteries in 2010 cost US $1,183 per kilowatt hour. Now they are around $150 per kWh and are expected to be less than $100 within three years. On the solar panel side, Cleantechnica reports that in 2010 they cost 12 times as much as they do now!

Bright future for solar electric boats

lithium battery packs being put together by Michael and Heiki Kohler in their boathouse in 2008By February of 2018 the SILENT-64 model was being manufactured and became the first fully solar powered production yacht to cross the Atlantic Ocean. Now, about 15 years after Michael and Heiki were putting together their first boat, they have 31 yachts about to be delivered, and the company is also working on an innovative resort project where batteries on the boats can feed electricity to onshore facilities.

It’s not just Silent-Yachts, either. Soel Yachts of the Netherlands just launched a 48′ solar electric catamaran, Slovenia’s Hovercraft has the Electricat, an inflatable solar catamaran, and Azura Marine’s Aquanima 40 catamaran as well as the solar powered Aditya ferry by Navalt were both winners in the Gustave Trouvé Awards for electric boats and boating.

No doubt about it, the future is sunny for solar powered boats! (pun intended 🙂 )

Exciting things are happening every day in electric boats and boating.
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2 thoughts on “Silent Yachts: 500 lithium battery packs, 2.5 megawatts on order

  • November 15, 2020 at 4:09 pm

    Please, don’t forget, that battery capacity is measured in Kilowatt*hours. Kilowatts or Megawatts are just power.

    • January 4, 2021 at 12:46 pm

      Yes, thanks. It is clarified in the body of the article, but not in the headline, mainly for brevity.


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