Q&A2019-11-12T11:50:30+01:00
What is the difference between a Silent Yacht and a conventionally powered yacht?2018-06-15T23:46:50+01:00

Conventional motoryachts are powered by diesel- or gas-engines. Additionally they use to have a generator on board to supply all household appliances.

Depending on the size of the yacht, in sum 2 or 3 diesel-engines are working for propulsion and household.

Also sailing-yachts need a diesel-engine. Depending on the operational area and the wind- and weather-conditions, additionally to the sails a diesel-engine is needed for the propulsion of the boat. When anchored in a quiet bay, the diesel-engine ensures the energy-supply of the consumers.

Most yachts are using gas for cooking, the open flame heats up the interior of the yacht and cause an imminent threat. On many yachts the consumables like water and energy are managed in a way that enforces the skipper to visit a marina every two or three days to charge the batteries and to buy water for shower and drinking. Larger Yachts operate water-makers, air-conditioning and generators. They do not need to got to a marina but they have to run the generator.

The use of a combustion-engine is inevitably combined with noise, exhausts vibrations and oily films in the water. Is it that, what you are looking for in an otherwise quiet bay?

A conventionally powered boat has a range of 300 to 500 nautical miles under diesel-engine. With a sail the range can be extended – but only when the wind is coming from the right direction and in matching force.

Are there different cabin configurations for each SILENT yacht model?2019-11-12T19:54:10+01:00

All SILENT yachts can be configured in several different layout versions. Details can be found on the designated page of each model.

Can SILENT yachts be built for commercial use, for instance as passenger ferries?2018-07-03T23:56:06+01:00

Yes, we did it already! For commercial use the boat probably has to be customised to your needs. Just as a ballpark figure – for commercial use as a public transport ferry, e.g. with up to 50 seats, the boat requires less interior but more safety-equipment and typical commercial adaptions. Depending on the applicable regulations and required certifications as well as on the chosen options (high power motors, larger battery capacity, VIP version or simple transport version) the price can vary significantly.

What yachts are currently under construction? What are your future plans?2018-07-04T07:18:38+01:00

Boats in water:

  • 1 Solarwave 46 Cruiser – Lauched 2009
  • 2 SILENT 55 „E-Power” – Launched June 2018, June 2019
  • 4 SILENT 55 “Sailor” – Lauched 2017-2018
  • 4 SILENT 64 “Cruiser” and „Hybrid” – Launched in 2016 – 2019

Boats in production:

  • 1 SILENT 55 “E-Power”
  • 6 SILENT 60 “E-Power”
  • 5 SILENT 80 “E-Power”

Sea-trials:

  • SILENT 55 “E-Power” – Summer 2020 in the Mediterranean
  • SILENT 64 “Cruiser” – Summer 2020 in Turkey
How does cooling and heating work?2018-06-15T23:38:50+01:00

When the windows have to be closed in bad weather or when mosquitoes are outside, you will enjoy using the unique aeration-system. It is installed in all cabins, bathrooms and the saloon. It provides individually adjustable cool and fresh air at any time. It also can be combined with the air-conditioning. The roof  overhang and the UV protection of the saloon windows also help to keep the inside of boat cool. In reverse mode the heat-pump provides a cosy interior for an all-season use.

What is the difference between a Silent Yacht and a conventionally powered yacht?2018-06-15T23:46:50+01:00

Conventional motoryachts are powered by diesel- or gas-engines. Additionally they use to have a generator on board to supply all household appliances.

Depending on the size of the yacht, in sum 2 or 3 diesel-engines are working for propulsion and household.

Also sailing-yachts need a diesel-engine. Depending on the operational area and the wind- and weather-conditions, additionally to the sails a diesel-engine is needed for the propulsion of the boat. When anchored in a quiet bay, the diesel-engine ensures the energy-supply of the consumers.

Most yachts are using gas for cooking, the open flame heats up the interior of the yacht and cause an imminent threat. On many yachts the consumables like water and energy are managed in a way that enforces the skipper to visit a marina every two or three days to charge the batteries and to buy water for shower and drinking. Larger Yachts operate water-makers, air-conditioning and generators. They do not need to got to a marina but they have to run the generator.

The use of a combustion-engine is inevitably combined with noise, exhausts vibrations and oily films in the water. Is it that, what you are looking for in an otherwise quiet bay?

A conventionally powered boat has a range of 300 to 500 nautical miles under diesel-engine. With a sail the range can be extended – but only when the wind is coming from the right direction and in matching force.

What kind of batteries and storage capabilities are built in?2018-07-03T23:45:35+01:00

Lithium batteries – high energy density,  the same product as Tesla uses. To be more flexible, we always use the latest generation which is a bit more powerful. The storage capacity depends on the chosen configuration, it enables you to go up to 20 knots and to run air conditioning all night without the need to start the generator.

Which company builds the electric propulsion system?2018-07-03T23:50:53+01:00

We do this ourselves by using high quality industrial grade products, which we configure in a special way that makes the system unique.

Can you summarise the testing process of the first Solarwave 46? What did you learn that has had the biggest impact?2019-11-12T19:56:13+01:00

We ran the following long-term tests:

2005-2009 with a converted Fountaine Pajot 37, in which we installed the same household appliances as on our current boats – fridge, freezer, washing machine, electric oven, induction cooktops, coffee-machine, bread-maker and a water-maker. In addition we installed solar-panels and wind-generators and all necessary equipment to measure the energy production and consumption.

2010-2013 with Solarwave 46, a dedicated solar-yacht which we launched in 2009. More then 12.000 miles exclusively solar-powered, you can find more information here: https://www.silent-yachts.com/history/
We found out, that spending less is the key factor, so we worked a lot on reducing the energy consumption e.g. by insulation the hull to increase the efficiency of the AirCon and we optimised the hull and the propulsion system for higher performance and less consumption.

How was the decision made to be fully hybrid-electric, with no fuel onboard (except the diesel generator set as a range extender)2018-07-04T07:09:37+01:00

After several years of testing we found out, that the overall energy balance of solar-panels is much better than of a sail. In an average application – holiday boat or world traveller, the energy produced by the solar-panels – which are specially designed for this purpose – exceeds by far the energy produced by the sails for propulsion. It is a simple fact, that you use a sail only a fraction of the time, whereas the solar-panels produce energy every single minute of daylight, energy you can use for propulsion AND for cooking, cooling the boat, refrigeration, washing-machine, water-maker etc.

How many kW do the panels generate?2018-07-04T07:13:17+01:00

On the SILENT 55 about 10 kWp, which results in about 60 kWh per day. This enables you to travel up to 100 miles every day, exclusively powered by the sun and run all the amenities like air conditioning, TV etc. as well as domestic appliances.

What about maintenance and warranty?2018-07-07T18:13:33+01:00
  • Virtually no maintenance – batteries, panels and e-motors are free of maintenance. Service interval for the only part you must look (the 2 bearings of the e-motor) after about 100.000 hours. Then the costs to exchange the 2 bearings is about 100 USD
  • The batteries have a warranty of 10 years, in 12 or 15 years you will get Lithium batteries of latest technology for less money than today.
  • The solar panels guaranteed lifespan 25 years – the same like with the batteries – in 25 years solar panels will be cheaper and more efficient.
  • Only the small generator which is on board for safety reasons needs some attention. Last year we spent 300 USD for the service of the Generator on our demonstration yacht – ridiculous for about 4.000 miles on e-motors…
Do you provide enough energy for a Water Maker?2018-07-07T18:19:18+01:00

Yes, of course! The watermakers we recommend consume only 300-400 Wh to produce 100 liters of drinking water. So with 1 kWh you can produce about 300 liters. We offer watermakers that produce 100 to 450 liters per hour. As the consumption even of the big watermaker is only a fraction of the production of the solar panels, the water production can easily be supplied by the solarcpanels – or during the night out of the batteries.

Which CE Category you provide for a SILENT Yacht?2018-07-07T18:22:34+01:00

All our Yachts come with CE Category A! *) This is the highest class in Europe. Silent Yachts are designed to circumnavigate the world. If you require further reinforcement of the hull e.g. against ice, we can discuss it and build it accordingly.

*) CE A Certification means: 
Category A: Ocean. This is the category with the toughest standards and covers vessels of 40’ and over designed to be self-sufficient for extended voyages. It is defined as the “category of boats considered suitable for seas of up to 23 feet (7 meters) significant wave height and winds of Beaufort Force 9 (41-47 knots) or less but excluding abnormal conditions such as hurricanes.”

Can the generator both charge depleted batteries and power the ship (e.g. air, stove, lighting) while the boat is underway?2018-07-07T18:25:33+01:00

Yes, of course. Just to make this clear: The generator recharges the batteries when necessary. It is NOT required to start the generator for the operation of household appliances, not even for cooking. You do not even need to start the generator for higher speeds. Only when you go for a longer distance at higher speed the batteries could get depleted, so it is best to start the gen in such a case. Just to give you an idea – you can go for 12 hours solely on batteries (during the night) at 6 knots speed. About 100 nm per day are feasible without starting the generator. If you want to go faster, the gen runs a short time a day.

What about the Kite Sail System? Is it available for all types of your yachts?2018-07-07T18:42:04+01:00

 The prices of the Kite-Boat and the SkySails systems are almost similar to a complete performance rigg (including sails, all winches, rails, blocks, ropes, mast, boom, stays and all other parts and reinforcements required for a standard rigg) but Kite-Boat and SkySails systems come with the big advantages of a kite:

  • does not create any shade on the solar panels, which doubles the energy production per day.
  • has a much higher performance than a sail on courses from 90 – 180 °.
  • significantly less and lower cost maintenance than sails
  • safer, quieter, up-to-date technology

An article about the cooperation between SkySails and SILENT-YACHTS you can find here. More details about the SkySails system you can find in this document.

The KiteBoat system is available for the SILENT55, which has the sail option too. The Kite-Boat and SkySails systems are both available for SILENT 60 and SILENT 80.

Q&A with Michael Köhler at Cannes Yachting Festival 2019!

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