Silent Revolution Silent-Yachts
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Silent Revolution Silent-Yachts

How did the Austrian family set up mass production of yachts operating entirely on solar energy?
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Catamarans built by Austrian shipyard Silent-Yachts, the language does not turn to call motor. On the one hand, they are all equipped with generators. On the other hand, they can all run on the same solar power for potentially unlimited time. The founder of Silent-Yachts, Michael Köhler, prefers to compare his creations with sailing yachts. «Our boats are driven by the power of the sun, which is similar to the power of the wind. After all, it's the sun that creates the wind, acting like a big wind turbine»," he says.

Unlimited range is guaranteed provided that you walk at an average speed of four knots, doing no more than 100 miles per day.

«If you want a speed boat, please buy something else»," says Köhler.

Silent-Yachts catamarans in the E-Power version can reach a top speed of up to 20 knots, but at this speed you can only show off to your neighbor»for a «few minutes, he admits.

«Usually our yachts are sailing at 6-8 knots in clear weather. If you have to walk a short distance, you can easily walk at 8-10 knots for two or three hours»," adds the Silent-Yachts chapter.

These are modest numbers by motor standards, but it must be borne in mind that all life support systems on Silent yachts are also powered by solar-powered electric motors. You have not misheard - everything, including the energy-efficient air conditioning system and the oven.

These are boats for people who like to anchor somewhere in the picturesque harbour.

«Just imagine: you no longer have to start a four- or six-cylinder engine to just cool your beer»," says Köhler.

«A journalist came to us and said you can tell me anything, but I still don't believe it's true, because I know how much my boat burns fuel»," he continued. And he invites all skeptics to see the results of years of testing Silent-Yachts catamarans.

The first model was launched in 2009. It was a 46-foot catamaran built under the Solarwave brand. The company founders Michael Koehler and his wife Hike tested the 46 for five years. They crossed all of Europe by river, went through the Black and Aegean Seas and entered the Mediterranean. In addition to two skippers, there were six to eight passengers on board at different times. People prepared, cooled and warmed the cabins, took showers - all on electricity.

In five years of travel, the generator worked for only about 50 hours.

Most of this time came during the particularly frosty season on the Rhine, when the generator was used for additional heating of internal rooms.

At the end of the test five years, the catamaran has found its owner, who uses it to this day. In nine years the boat has rolled back eight seasons and the only thing it had to replace was the MPPT solar regulator.

«We received a new one from the manufacturer free of charge, with the words that this should not have happened in principle. Plus, we had to give the generator to the maintenance company because of the long downtime: it hasn't been used for three years»," says Köhler.

When the 64-foot model - the serial successor to the 46-foot model - came out, she was also given a test, though not as long.

The Chollers rolled back for the 64th 12 weeks. They drove clients and journalists four times around the Balearic Islands without burning a single litre of fuel.

«Is there any other boat on the market that can do that?» - Michael's asking.

Last winter, the 64-foot Silent made the transatlantic transition - this time with its owner. It took about 1600 liters of fuel from Spain to Barbados. This «brutal» consumption was due to the fact that the owner was in a hurry to a party organized by him on the popular beach Nikki Beach.

At the end of this trip, Silent 64 arrived at the Palm Beach International Boat Show without a single breakage, although the weather on the way was poor.

The secret to Silent Yachts' success is in its holistic approach to development.

In order to provide their yachts with exceptional energy efficiency, they operate from all fronts: they reduce the consumption of life support systems, increase the energy efficiency of the hull, its thermal insulation properties, the power of solar panels and the battery capacity.

Silent 55 solar panels have enough area to generate 10 kW/peak. That's 50 to 60 kWh per day. The 64 has 15 kWh/peak, which is the equivalent of 70-90 kWh per day. And the top 79-foot model, which has already begun construction on the Silent-Yachts docks, is equipped with 25 kW/peak solar panels. That's 150 kWh per day.

The smallest of the three models in the Silent-Yachts range can be optionally equipped with a sail and all three models - 55, 64 and 79 feet - with a kite.

The latter, according to Köhler, is preferable: the kite is smaller than the sail and does not cast a shadow on the main power source of the yacht - solar panels installed on the roof. The principle of the kite's operation is simple - it inflates and goes upwards, giving the boat extra pulling power. The autopilot controls the kite so that it spins in the air of the «eight». According to the manufacturers of this system, the efficiency of the kite increases as if its area is 20% larger than the real one.

Prices for Silent-Yachts electric catamarans are comparable to those of Lagoon and Fountaine Pajot motor catamarans of the same size.

«Yes, of course they have a bigger and more powerful engine, but we offer unique possibilities," says Michael Koehler, founder and head of Silent-Yachts. - We also have a wide range of standard equipment, including powerful generators. For example, the power of Silent generators 55 - 100 kW against, at best, 25 kW of competitors».
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