Does the Solarwave 64 make solar-powered boating a reality?

The production-ready solar-powered Solarwave 64 powercat solves the limited-range conundrum of true electric boats

Solarwave 64The efficient, low-drag hull of the cat is ideal for solar applications
Even by conventional motor yacht standards, it’s an impressive-looking beast with a vast owner’s suite occupying the whole of the starboard hull and two further double ensuites on the port side (four and five-cabin versions are also an option). But it’s the way the whole boat has been designed and built from the ground  up as a self-sufficient solar-powered cruiser that makes it so unusual.

Unlike the hybrid diesel-electric craft from the likes of Greenline and Mochi, which still rely on a sizeable diesel engine for any lengthy cruises, and the range-restricted battery-powered pure electric craft from Nimbus and Frauscher, the Solarwave 64 can cruise in near total silence for days at a time. So long as the sun keeps shining, there’s no theoretical limit on how far you can keep motoring.
Solarwave 64A 25kW generator can be used to extend the range if the batteries run flat
The choice of a multi-hull design makes perfect sense. Not only is it an inherently efficient low-drag hull shape, but the large surface area of the pop-up hardtop and flybridge overhangs provide the perfect place to locate the solar panels.
On a sunny day, these can generate up to 15kW – more than enough to propel the boat at 5-6 knots and power all the yacht’s household appliances.
A huge amount of effort has also been put into keeping the weight down through the use of carbon-fibre composites and structural honeycomb-cored furniture. It hasn’t quite hit its initial target weight of 18 tonnes light but even at 25 tonnes, it’s a full 10 tonnes lighter than a Lagoon 630.

The production-ready solar-powered Solarwave 64 powercat solves the limited-range conundrum of true electric boats

Solarwave 64One of three double cabins on the first boat. A four-cabin layout is also possible
The proof of this was demonstrated by the original 2009 Solarwave 46 prototype, which underwent a rigorous five-year sea trial around Europe, clocking up over 2,500 hours on the electric motors but a mere 50 hours on the generator, most of which were added to prevent it seizing up from lack of use.
The inclusion of a 10kVA inverter and an all-electric galley as well as air con, heating and a watermaker as standard means that you should be able to cruise for weeks at a time without having to visit a marina.
Solarwave 64 The luxurious saloon shows no compromises are necessary on a solar-powered vessel
For those who insist on a higher speed capability, there is also an option to fit larger electric and diesel engines delivering 20 knots or more. So far, just the one 64 has been completed with a second one in build. Unfortunately, limited capacity at the third-party shipyard contracted to build it in Turkey means the next available delivery slot for the 64 is in 2019.

Solarwave 64Masses of living space on the 31ft 2in (9.5m) main deck
That’s why the Swiss parent company Silent Yachts is now focusing its attention on two new models it’s having built in China – a 54ft cruiser with prices starting from €1.13 million ex VAT due out this October, and a 70ft cruiser pencilled for launch in spring 2018 at an undisclosed price.
The Silent 54 is being offered with a variety of electric power options from twin 25-135kW motors each side and Volvo or Mercruiser diesel power from 75hp-220hp. The Silent 70 will get more powerful 50-135kW electric motors and up to 2 x 400hp diesel motors.
With five orders already taken for the new Silent 54 and one for the new 70, it looks like this could be the start of a quiet revolution.
Technical details
Length 63ft 9in (19.43m)
Beam 31ft 2in (9.5m)
Draft 3ft 7in (1.1m)
Motors Twin 20kW electric (60kW option)
Top speed 10 knots (electric only)
Displacement 25 tonnes (light)
Water capacity 1,000 litres
Fuel capacity 1,000 litres
RCD category A for 12 people
Price from €1.96 million ex VAT