In hybrid cars, an internal-combustion engine is complemented by an electric motor. The same concept creates more energy-efficient, environment-friendly boats.
Slovenian boatbuilder Greenline has taken up this challenge, producing a range of hybrid launches. And going one step further than hybrid cars, where the battery’s charged by the fuel-burning engine, these boats also collect and store energy from the sun.
Greenline currently produces four hybrid models – a 33, 39, 40 and 48 – with a new 44 coming off the
production line next year. All combine a new-generation Volvo diesel with a generator/electric motor unit, sitting within a ‘superdisplacement’ low-drag hull design for efficient motoring. They use traditional diesel power for passage-making, and switch to the electric motor for slow cruising, manoeuvring and docking.
The lithium-ion battery pack can be charged by shore power, the diesel’s alternator or via four large
solar panels on the roof. The advantages echo those of a hybrid car – fuel saving and environment-kindly – as well as quiet operation and no smelly fumes. Hybrid Boats is Greenline’s New Zealand agent, and owner Richard Wardenberg says ex-yachties wanting to convert to a launch are attracted to hybrids for this very reason.
The latest model to arrive here is the Greenline 39, a tad under 12m LOA. She was named Boat of the
Show in the launch category at the 2017 Hutchwilco New Zealand Boat Show, on top of other honours
Greenline began building hybrids a decade ago. The concept belongs to two brothers, Jernej and
Japec Jakopin, whose design company J&J (founded in 1983) has designed for Elan, Bavaria, Beneteau and Jeanneau. It’s also worked with America’s Cup designers Guillaume Verdier and Doug Peterson on the Shipman 59 full-carbon race boat.
Seaway, the Slovenian company which builds the boats, got into financial trouble during the GFC, and was bought by a Russian businessman who has interests in alternative fuels. Since his investment the company, rebranded as SVP Yachts, has stepped up production, building a new solar-powered factory which aims to churn out one new boat a day to meet worldwide demand.
We took out a pair of Greenline 39s on a glorious late-winter day: a hybrid, part-owned by Hamish Neal, and Wardenburg’s own conventionally-powered diesel model. The two boats look identical from the outside but have different interior colourways: Neal’s boat, Dragonfly, has a warm teak interior, while Wardenburg’s has the lighter white oak.
The Greenline is a sedan-style launch with a touch of Euro styling in the low-level, angular porthole panel which makes a statement forward. The boat’s hard chines and spray rails also give it a modern, European look. Neal’s group had previously owned a diesel-powered 10m Greenline 33, but wanted to move up to a larger model – and embrace the green technology.
The transom folds right down (operated by a remotecontrol fob, like a garage-door opener) and forms a large boarding platform. There’s a bench seat to port and a smaller single seat to starboard, and easy access to storage lockers under the teak flooring.
Under the port seat is the reverse-cycle air conditioning/heat pump – the Greenline Hybrid is the
first production boat internationally to offer the unit as a standard feature, thanks to the high availability of electricity.
The rear of the cabin is closed off with highly-reflective, one-way glass, to provide privacy when moored stern-on as they do in the Mediterranean. The large door slides open and a window above the galley bench lifts up on a hydraulic ram, opening the cabin right up to the cockpit. A section of bench can then be extended to create a servery.
This makes for a light and bright galley connected directly to the cockpit. But what might raise an
eyebrow are the appliances within it: no gas burners and oven or under-bench chiller. Instead, there’s an induction cooktop, electric convection oven (both produced by Slovenian manufacturer Gorenje) and full-domestic-size integrated fridge-freezer unit. Once again, if your boat’s producing electricity while it runs, why not use home comforts?
Forward of the galley is the slightly raised saloon, with u-shaped seating around a table which can be
lowered to create another berth. To starboard is a credenza which conceals a pop-up flat-screen TV. This can be replaced with an extra bench seat if required.
The elevated helm station is forward of this again, providing excellent visibility when seated or, with the hatch above opened, standing. A sliding door from the helm position leads out onto the side-deck and forward onto the bow. The deck layout is asymmetrical: there is a walkaround only on the starboard side.
“New Zealanders like one-level living – they get sick of sitting upstairs on the flybridge in the wind, and don’t want to be going up and down ladders,” says Wardenburg. “With the big windows in the saloon you don’t feel like you’re stuck in the cabin.”
Mounted above the teak steering wheel is a large Raymarine chartplotter. Alongside are controls for the Volvo diesel and bow thruster, and the hybrid-diesel switch. The Simarine battery monitoring system shows generator power and battery storage levels.
Dropping down forward, there is a twin cabin on the port side (the two beds can be pushed together to make a double) and the master suite in the bow. This can also be configured as a twin or a double, with the beds pushed together.
The Jabsco electric head and shower – in a separate enclosure – is semi-en suite, also accessible from the vestibule at the base of the steps. There is plenty of hanging locker storage in both cabins, and the master cabin is flooded with light from deck-level and through-hull windows. A sliding
hatch lets in a little extra light from the saloon above in the second cabin.
Up on the bow is plenty of room for relaxing, with large squabs clipping to a raised central area to create a lounging area. Wardenburg says this is a popular place to sit when slow-cruising under electric motor: “In hybrid mode you find everyone sitting on the bow, or you can fish off the side of the
walkway or the back – some people say ‘it’s not a fishing boat’, but in my experience the fishing is phenomenal. And for some reason dolphins seem really attracted to the hybrid motor too.”
Under the saloon floor is the business end: the 220hp Volvo diesel, linked to a 10kW Mahle
generator. The bank of lithium-ion batteries is concealed under one of the forward berths. In
electric drive mode, the batteries supply power to the electric motor, and when in engine mode the
power generated drives the boat but also recharges the batteries. To top it off, the roof-mounted solar
panels generate 1.3kW during daylight.
“Basically, the whole boat is a power plant,” says Wardenburg. “With the batteries fully charged,
and with 1.3kW from the solar panels, you could motor all the way to the Bottom End [of Waiheke] using only electric power. When the low-battery alarm goes off, it only takes about 20 or 30 minutes to get back to 40–50 percent charge again.”
Around 20 nautical miles at 6 knots (under battery power) provides a reasonable range for pottering around the Hauraki Gulf or Marlborough Sounds. When you want to go a bit faster, or need to charge up, the hybrid cruises at 10–12 knots, with a top speed of around 18 knots. By contrast, Wardenburg’s
full diesel model, powered by a 370hp Yanmar V8, has a top speed of 25 knots.
While it’s impossible to tell during our glass-calm day, Wardenberg says extensive tank testing and research has gone into creating a hull which is not only super-efficient but also stable and comfortable in a seaway. “It’s all about what’s under the water – seakeeping ability, efficiency, low centre of
gravity and weight distribution. Stability is a big factor – they really wanted a boat that doesn’t roll.”
We head out from the marina in e-mode. It’s a strange sensation to be moving without any noise or sense of vibration: Neal has simply pressed the ‘on’ button and we’re underway. It’s astonishingly quiet; the only noise is the faint buzzing of the electric engine, like a tiny sewing machine under the floor.
“It’s really good at very slow speeds, for manoeuvring within the marina and into the berth,” he says. “It’s quite nice just stooging around. For passage-making you could ignore your diesel if you weren’t in a hurry.”
The switch from hybrid to diesel is a touch of a button. Neal puts the gearbox into neutral, turns the dashboard switch to diesel and presses the start button – and away we go. The modern diesel is nice and quiet too.
The Neals own Dragonfly in partnership with another couple – an arrangement he says has gone from a business relationship to good friendship in short order. Over summer they plan to give her plenty of use, cruising the Gulf and using the mix of electric and diesel power to explore at leisure. Neal is a convert to electric-powered transportation, and plans to order a Tesla Model 3 electric sports car.
“I’m so keen to get rid of fossil fuels – I’m just glad I’m seeing it happen in my lifetime,” he says. “The idea of a hybrid power really attracted us to the boats in the first place. People talk a lot about hybrid cars, but not boats. But when the Le Mans 24-Hour Race is using hybrids, you know things are changing pretty fast.”