Azimut and Volvo Penta have combined forces to develop the most advanced hybrid production boat yet. Hugo Andreae reports
The Azimut Seadeck 7 may not be the first diesel electric hybrid boat but it’s almost certainly the most significant. That’s because it brings together two of the biggest names in boat building – Volvo Penta and Azimut Benetti – and where those two go others are certain to follow.
The result of this technical collaboration is the most advanced hybrid boat yet, offering all the style and luxury of a high-end flybridge cruiser with the performance, reliability and fuel efficiency of a fully approved Volvo IPS drivetrain. The big difference is that it can do all this while delivering up to four hours of electric emissions-free cruising.
Seamless Power
The heart of this revolutionary new drivetrain is a pair of 1,000hp Volvo D13 diesel engines linked to IPS1350 pod drives but inserted between them on the same output shafts are two 160kW (215hp) electric motors.
These run in parallel with the diesel engines so they can either be used to propel the boat on electric power alone or in conjunction with the combustion engine. Crucially, they also double as powerful shaft generators, enabling the main engines to recharge the 400kWh lithium ion battery pack and replacing the need for a separate diesel genset or range extender.
The diesel powered Seadeck 7 is available now but the hybrid version is still undergoing long-term testing
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Watch the videoControlling it all is Volvo Penta’s own glass cockpit Electronic Vessel Control (EVC) system, ensuring seamless automatic switching between the various hybrid modes in what Volvo describes as the first full ‘helm-to-propeller’ hybrid package.
The aim is to make this technologically complex drivetrain as easy and intuitive to use as a conventional diesel engine. Much like today’s hybrid cars, all the driver has to do is apply the desired amount of throttle and leave the software to work out which power source to use and when.
In most situations this will largely come down to speed; below 11 knots the electric motors are the default option as long as there is sufficient charge in the battery pack. Above 11 knots the diesel engines kick in automatically, delivering the necessary power to push the Seadeck 7 up to its quoted top speed of 32 knots.
The two 1,000hp D13 engines are supplemented by 160kW electric motors and a combined battery pack of almost 400kWh
This is all taken care of automatically when using the Hybrid Standard mode. For owners who want to play a more active role in selecting which power source to use, the software does allow you to select three other driving modes: Pure Electric, Hybrid Boost and Crossover Mode.
Boost Mode
In Pure Electric the speed is restricted to 11 knots but you’re better off limiting it to 7 knots and enjoying over four hours (30nm) of silent emissions-free cruising. As the name suggests, Hybrid Boost enables the electric motors to provide a temporary extra kick of acceleration, which is particularly handy for helping the hull transition from displacement to planing.
However, it’s the Crossover Mode that brings the biggest potential win for serious cruising types as it allows one diesel engine to drive both propeller shafts – one directly from the engine’s gearbox, the other via electrical energy diverted to the other shaft’s motor.
It’s as easy to helm as any other boat
Not only does this make for exceptionally fuel-efficient cruising, by allowing the active engine to run at peak efficiency while ensuring no energy is wasted, but it also halves the number of running hours on each engine, saving on servicing costs and reducing wear and tear.
To make the most of this potential, Azimut has designed the rest of the boat to be as efficient and sustainable as possible. The low drag hull is built using a core of recycled bottles, the deck is covered in reconstituted cork, weight is reduced by using vacuum-infused carbon-fibre rich mouldings and even the carpets are fashioned from recycled materials – including old fishing nets!
Silent Progress
If this all sounds like a lot of effort and expense for a relatively small gain, both parties are keen to point out that it’s not just about reducing greenhouse gas emissions, impressive as the claimed 40% reduction in CO2 is. A big part of its appeal is the increase in refinement and comfort.
Even the carpets are made from recycled fishing nets
As well as a significant reduction in noise and vibration when cruising in electric mode, the huge battery pack means all the yacht’s systems, including the air-conditioning and both gyro stabilisers (it’s fitted with a Seakeeper 6 and 9 for maximum versatility), can be run for up to 12 hours at anchor without engines running.
Whether buyers are prepared to pay a significant premium for the full hybrid package remains to be seen. Both Azimut and Volvo are committed to offering it as a factory-fit option on the Seadeck 7 but until they have completed a year’s worth of sea trials on the project boat, they won’t be drawn on pricing. Until then would-be Seadeck 7 owners will have to make do with a conventional pair of IPS1350s and an already punchy price of €3.3m ex tax.
Seadeck 7 specification
LOA: 71ft 2in (21.7m)
DISPLACEMENT: 43 tonnes
BEAM: 18ft 1in (5.5m)
ENGINES: 2 x 1,000hp Volvo ISP1350
MOTORS: 2 x 160kW
BATTERY PACK: 400kWh
FUEL CAPACITY: 3,700 litres
TOP SPEED: 32 knots
PRICE FROM: €3.3 million ex tax
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