Updated: Aug 3, 2020
'Good design, is sustainable design...'
This week we spoke to Silent Yachts, who believe in a 'world where yachting works with nature rather than against it'
Our vision is to establish a new era of sustainable yachting by creating the most innovative and self-sufficient yachts.
We absolutely love your concept at Silent Yachts, can you give us a bit more information about how the idea came to life?
Michael & Heike Köhler are the solar-pioneers behind SILENT-YACHTS. As both their hearts were longing for the open blue, they travelled the oceans for over 23 years on conventionally powered sailboats and motorboats. They both spent over 5000 days on board of their yachts and sailed over 75,000 NM around the world. The experiences they gathered during more than two decades at sea lead them to the conclusion that there had to be a more efficient way to supply yachts with energy. After four years of continuous research, this lead to the birth of the SOLARWAVE 46 in 2009.
It was nothing less than the first ocean-going yacht which exclusively used solar energy not only for actual propulsion, but also to provide energy to all household appliances on board. This includes everything ranging from cooktops, stoves and the freezer to the air conditioning, washing-machine and water-maker.
How do you ensure that you don’t sacrifice luxury for sustainability?
Instead of perceiving sustainability as a disadvantage in terms of providing the highest levels of luxury, we actually see it as an advantage. The solar energy is not only used for propulsion, but provides energy to all household and navigational appliances on-board. This means you can enjoy anchoring in a quiet bay whilst taking full advantage of all the luxurious amenities on board without the noise, vibration, fumes or smell of a running generator.
Can you explain to us at SSY how you are using solar power onboard your yachts, is it mainly for propulsion or can it also be used for supplying energy to other areas e.g air conditioning?
Solar power is used for the propulsion as well as for powering all household appliances on board. This also includes the air conditioning as well as for example the induction cook-tops, fridge, navigational instruments and other consumers. To be able to make use of the energy provided by the sun also during the night, we have large lithium battery banks that store the energy gathered during the day.
We know that one of your yachts did an Atlantic Crossing purely on solar power, this is amazing, how many miles a day can the yacht travel for purely on solar power? And are there any issues with battery fatigue?
A SILENT 55 for example is able to travel up to 100 miles per day exclusively by the sun. If higher speeds are required or during unfavorable weather conditions, you have a back up generator on board which refills the batteries. During the Atlantic crossing, the SILENT 64 was mainly sourced by the power of the sun. The boat traveled almost 5,500 nm from Spain to Barbados. It was a non-stop journey of 34 days. Due to bad weather conditions and rainy weather for an entire week, the captain had to make use of the range extender in some cases.
How does the battery capacity impact the space/storage onboard?
The situation is very comparable to an electric car. As an electric drive train requires much less space than a regular drive train making use of fossil fuels, this benefits the space available in the cabins and throughout the boat. This means that our yachts actually offer their guests more interior space than a similarly sized motor catamaran with a combustion based propulsion system. If you upgrade a SILENT-YACHT with the biggest battery bank that we offer , you will not lose any space as the battery banks are hidden under the floor.
Is there the ability to run under battery for a few days at anchor with a full crew and guests and those power hungry demands? (e.g AC, water makers, cooking, cruising between anchorages etc)
Yes there is. This is one of the major benefits of our system. On average sunny days, you are able to enjoy all the amenities on board while anchoring in a bay without the necessity to turn on the generator.
What's the life expectancy of solar panels within marine environments?
We grant 25 years of warranty on the solar panels.
Do you take sustainability into mind when building the yacht? e.g sustainability of the yard?
One of the main benefits of our technological philosophy is the aspect of modularity. All the vital components such as the solar panels and the battery packs can be easily replaced and even be upgraded whenever there are new developments available on the market. For example, after several years of use you could upgrade the battery bank of the yacht and use the old battery bank as a energy storage system for your house. This makes sure we can re-use the components to minimize the waste produced and maximise the actual usage.
Have you had any requests for any larger yachts than already in your range? Do you see demand in this category increasing at all?
Yes, there is definitely interest in larger SILENT-YACHTS. It might happen that our fleet will be enlarged in the future.
Do you have any other sustainable concepts in mind when designing the rest of the yacht - with materials/interior etc?
We believe that sustainability in yachting requires a holistic approach for sure. This goes beyond the solar electric drivetrain. We very recently started a partnership with Ecoworks marine for example - the leading company for sustainable marine cleaning products. Collaborations such as these will keep developing over time to cover as many aspects of sustainability as possible.
At the moment you design motor catamarans, do you have any future plans for sail catamarans?
We have no future plans for sail catamarans as it diminishes the benefits of our solar powered philosophy (sails put shades on the panels). However, all our models are available with an optional kite sail system.
You were the first boat builders to produce exclusively solar powered yachts, which is amazing, we understand the yachting industry doesn’t hold the greenest of credentials but can see developments in the future, what future plans do you have?
Our vision is to establish a new era of sustainable yachting by creating the most innovative and self-sufficient yachts. We strive to manifest this vision day by day and continue to show consumers that they have the possibility of enjoying the ocean while preserving its purity at the same time. As sailors, we love the ocean, but we are also aware of our responsibility towards it. Therefore our founders felt like we needed to change the game altogether, and that is exactly what we will continue to do.
Has Covid-19 effected your progression with these plans?
While Covid-19 definitely represented a challenging situation, we were able to sell several boats and to deal with the circumstances effectively. Our shipyards proved their great organizational spirit and work ethic, making sure delays were kept to a minimum. From a client side, an increasing number of curious people approached us as the independence that comes with a solar powered yacht became apparent to a larger audience. Furthermore, the industrial lock down in many countries gave nature time and space to recover - with amazing results in countries such as China, Italy or the United States. Both these factors actually contributed to a larger increase and awareness of our brand, our mission and our values.
Thank you to Silent Yachts. For more information on their concept and design, visit their website.