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A new experience in power boating – hybrid electric power Many people have a love of boating. But boaties tend to fall into one of two camps, sail or power – and the two seldom see eye-to-eye. Power boaties find yachts a problem because they always seem to demand right of way (even when not under sail!) and yachties turn their noses up at power boats for being noisy, smelly and so on – they call ’em “stink boats”. But what if there was a power boat that could also appeal to yachties? There is: the Greenline 33. By LEO SIMPSON 16  Silicon Chip siliconchip.com.au With a casual glance inside the Greenline 33 you’d never know it was one of the most innovative craft on the water – you’d just think it was typical of the many luxury cabin cruisers available. It’s only when you “lift the lid” you find it’s not quite as it seems! T he Greenline 33 is a power boat but it is a power boat with a major difference – it is a hybrid. In some ways it is like a hybrid car, in that it has an internal combustion engine and an electric motor. But the drive set-up is quite different to car hybrids like the Toyota Prius, Camry, Honda Civic, Lexus 450h and others. Whereas most car hybrids can only drive a very short distance on electric power alone, if at all, the Greenline 33 can go for many hours when powered solely by its lithium-polymer batteries; 20 nautical miles at 5.5 knots in fact. But even more impressive, it can run at about 2.5 knots under solar power alone. So while ever the Sun is shining, it can just keep going under electric power. And when the Sun goes behind heavy cloud or you want to move along faster, you can start the diesel engine and really motor along at up to 15 knots. But while this boat can move at a very good pace, it does not have a planing hull and it does not gulp fuel when it is being pushed. In fact, at low speeds its fuel consumption is similar to that of a 30-ft Shore power mode – the boat is plugged in to 230V AC with battery charging etc. Electric drive – powered by electric motor via batteries, solar panel and/or generator if req. Solar panel roof Shore power Appliances Energy management Diesel drive – engine drives boat and charges batteries with up to 5kW output. Inverter/charger Gearbox Battery bank Clutch Electric motor/generator siliconchip.com.au Diesel engine The basic energy and power plan of the Greenline 33, with the various modes at right. At anchor – solar panel provides 230V AC power; diesel engine can provide charging. February 2011  17 Left: even with all the Raymarine electronics covered for protection, it still looks pretty much like a typical boat helm with throttle mounted on the starboard bulkhead. However, look a bit closer (right pic) and you’ll notice that big “hybrid switch” in the middle of the dashboard. Now that’s not something you see every day! yacht when under power. Powered by the diesel alone, its range is up to 700 nautical miles. That would get you from Sydney to Hobart! First impressions count . . . As I write this, I have just returned from several very pleasant hours on Sydney’s Pittwater in the Greenline 33. And while I came away from the trip with many impressions, the overriding characteristic of the boat is its silence. Under electric power it makes no more noise than a yacht under sail and even when running with the diesel it is very quiet. In fact, it can be called serene. So as you can see, it can potentially appeal to yachties and power boaters alike. Yachties will particularly like its serene progress while power fans will like the fact that it just sips fuel while still being able to move along at quite a good rate when required. Details The Greenline 33 is a single cabin cruiser with an overall length of 9.99 metres. In hybrid form it is powered by a diesel engine with the top option being a marinised VW TDI 125kW 2.4-litre 5-cylinder unit. The accompanying electric motor is rated at 7kW. This is mounted in line with the diesel engine and drives the single propeller via a standard forward/reverse gearbox. The major difference between the Greenline 33 and typical hybrid cars is that in the boat, only one motor can drive the propeller shaft. In hybrid cars, the petrol motor and electric motor can both contribute power at the same time. Hence, with the Greenline you could elect to leave your berth or mooring under electric power, moving virtually silently and with no wake. Depending on the state of the batteries you could run at up to six knots or up to 20 nautical miles (at a speed of four knots). If you wanted to get to your destination faster, you could change over to diesel. To do this, you must stop the electric motor and start the diesel. This has glow-plug ignition so it takes At left is the 2.4 litre, Volkswagen TDI 165-5 5-cylinder Diesel power plant, with the 7kW electric motor sitting behind it (enlarged view above). You have the choice of powering the vessel with the diesel engine only, with the electric motor powered by batteries and/or roof-mounted solar panel, or with the electric motor with the diesel running in generator mode to keep the batteries charged. (You cannot run with both the diesel and electric motors running together; a clutch disconnects the diesel engine when running under electric power). 18  Silicon Chip siliconchip.com.au travel with the cabin completely open and not worry about breathing in dangerous fumes. In fact, you can troll along at just a knot or two, with the large transom panel swung down to form a swim platform or you could have a fishing line or two in the water, to catch your meal. Magic! Mind you, the comment about lack of exhaust also applies when the Greenline is under diesel power because the exhaust is under water (wish mine was too!). Even with the hatch up, most of the electrics (as distinct from electronics!) is hidden from view, under cover for protection against wandering hands. This is actually the 48V 240Ah lithium polymer battery and battery management system. a short time to start. Then, you switch over to diesel and a clutch connects the diesel to the electric motor and the combination drives the prop shaft via the forward/reverse gearbox as before. However, now the electric motor becomes a generator with a rating up to 5kW and it charges the two 48V lithium polymer batteries which have total rating of 240Ah. Incidentally, being a lithiumpolymer battery, it is considerably smaller and lighter than an equivalent lead-acid battery. It weighs about 140kg whereas an equivalent capacity lead-acid battery pack would weigh as much as one tonne. Being a power boat owner myself, I was continually making comparisons between the Greenline and my boat. As already noted, the silent progress of the Greenline is the big point – under electric power it is almost eerily silent, depending on wind and wave conditions of course, but much quieter than any conventional power boat. The only time a “normal” power boat would be comparably quiet would be with the engines switched off! The other point of note was the lack of exhaust fumes. It’s not widely understood that a normal power boat of this type can suck carbon monoxide or other noxious exhaust gases back in through an open cabin rear door while under way. Because there are no fumes in the Greenline, this means that you could Super displacement hull Another point to note is that Greenline functions very well under electric power or even a smaller diesel engine because it has a patented “super displacement” hull which slides through the water more like a yacht than a conventional displacement hull. That’s not just advertising hype, it really is a different type of hull. While the Greenline cannot achieve the high speeds of a power boat with a planing hull, it can still move along at a maximum of 15 knots, which is considerably more than could normally achieved from a displacement hull with a water-line length of about 9.5m. In fact, “hull speed” for a displacement hull of that length is about 7.5 knots so the Greenline with its 125kW diesel can double that speed. And it can do that speed with much less fuel consumption than a similarly sized This photo wasn’t included to demonstrate the nautical prowess of the author (you might have noticed the boat is still at its berth!) but to show the roof-mounted 1.3kW solar panels which are quite capable of powering the boat along at a steady 6 knots in sunlight (or a little less under cloud). At right is the integral OutBack Power Systems energy control unit. It’s showing 65.4V <at> 0.4A input with 53.6V at 0.5A output. Note the bank of semicondutors alongside! siliconchip.com.au February 2011  19 Hybrid propulsion from Steyr planing boat. So electric or not, the Greenline 33 is a very economical boat to run. On the other hand, with its single propeller, the Greenline is not quite as manoeuvrable as a twin-engine boat which can typically be spun on the spot (with one motor in forward gear and the other in reverse). To partly address that drawback, there is an optional Side-Power SE40 bow thruster which really does help when you are berthing the boat. Interestingly, the bow thruster has its own 12V battery and is not powered by the main lithium-ion batteries which run the electric motor. Electrics While the Greenline 33 with its VW diesel is currently the only production hybrid pleasure motor boat available in Australia, there are other diesel hybrid systems for boats such as those from Steyr Motors GmBH, Austria. Steyr Motors have three diesel/electric hybrids available. Pictured is the MO256H45 which combines a 6-cylinder 3.2 litre turbo-charged diesel rated at 184kW (256 BHP) teamed with a 48V 7kW electric motor. This has four modes of operation. In the Starter mode, the diesel engine is started by the electric motor while in the generator motor, the electric motor is driven by the diesel to charge the batteries. In electric cruise mode, the boat is driven purely by the electric motor while the battery pack is constantly monitored by the Steyr Control Centre. Finally, in boost mode, the diesel’s power is augmented by the torque of the electric motor, depending on the demands of the driver and the battery condition. The other two models available are the MO144M38, a 4-cylinder, 2.1 litre turbo-charged 106kW (144 BHP) diesel, teamed with the same 7kW electric motors and the MO94k33 sail-drive unit which combines a 66kW (90 BHP) 4-cylinder 2.1 litre turbocharged diesel and the 7kW electric motor. The sail-drive unit is intended for use in yachts. At last year’s Sydney Boat Show we understand that the 6-cylinder 184kW hybrid unit drew a lot of interest from police and customs agencies who liked the possibility of an electric “stealth mode” – it could be a real surprise for water-borne law-breakers! For further information, contact Steyr Motors Australia, 33 Stone Street, Stafford, Qld 4053. Phone (07) 3356 9808. www.steyr-motors.com.au Having just mentioned the bow thruster, we should give some more information about the rest of the electrics. Another option on the Greenline is the 1.3kW solar panel array on the cabin roof. This charges the lithium batteries via a 48V solar battery charge management system. There are two other 12V batteries; one for the aforementioned bow thruster and the house battery which runs the cabin lights, instruments, pumps for water in the cabin and toilet/shower, anchor windlass, transom and so on. There is also a 48V to 230V AC 3kW inverter which provides power to run the air-conditioning and other nice Most unusual to see on a vessel this size – a full size fridge with freezer. In the foreground is a microwave oven and immediately above that an induction cooktop. Gives some idea of the luxury fittings you’ll find on the Greenline! 20  Silicon Chip siliconchip.com.au Specifications (as reviewed): Length overall: Beam overall: Draft loaded: Displacement empty: Cabins: Toilets/washrooms: Diesel tank: Water tank: Engine: Max speed: Speed under electric power: Range (elect. drive <at> 4 knots): Design: Engineering & development: CE Cat: Price: 9.99m 3.49m 0.70m 4800kg (approx) 1 plus saloon (sleeps 4/5) 1 430l 300l VW Marine TDI 165-5 15 knots 6 knots 20nm J&J Design Seaway B $333,333 features such as the full size fridge/freezer, microwave oven, ceramic cooktop, two 22-inch LCD TVs, DVD player and the list goes on. The solar panel can easily maintain the batteries on full charge if you are on a mooring (ie, away from mains power). If you do have 230VAC shore power available on a berth, you can use that to run the systems while you are tied up. The local agents tell me they never bother with shore power since the solar panel is more than adequate for the job, except for the occasions when the batteries need mains power for “balancing” (roughly once a month). By the way, when you are away from shore power, anchored in some secluded bay or inlet, you can also use the diesel engine and electric motor-cum-charger (with 5kW output) to charge the batteries and run all your appliances, including the air-con. This is the so-called “anchor” mode of the Greenline and is identical in principal to those large power boats which have an on-board petrol or diesel-powered generator, typically rated at 5kVA or more. The difference is that the Greenline does not need an additional heavy generator plus starting battery (maybe 300kg or more) which normally sits there idle. What more can I say? There is much more to interest any boatie, like the luxurious standard of finish and inclusions – on a par with our European boats such as Beneteau and Jenneau but we have covered the main technical points. It can be purchased as a basic diesel-powered boat at $243,333 or can be fully optioned up as described in this article, with solar panel, hybrid electric package etc, for $333,333, both prices including GST. For my money, the full Greenline 33 hybrid electric package would be the one to go for. You have all the benefits of silent electric power, minimal fuel cost, low engine maintenance and you still enjoy all the mod cons of a big power boat. Bliss on the water. For further information, contact Mark Whitman, North South Yachting Australia Pty Ltd, The Quays Marina, 1856 Pittwater Road, Church Point, NSW 2105. Lithium-Ion batteries have big advantages in boats Up till now, virtually all batteries for boats have been lead acid variants and these have the disadvantages of massive weight, physical bulk and are easily damaged if they are over-discharged. The massive weight is a double disadvantage in that it takes a lot of fuel to drag around in a boat and it also is a huge problem when a lead acid battery has to be replaced – getting heavy batteries out of cramped engine compartments is back-breaking work, usually involving two men. By contrast, lithium-ion batteries are a great deal smaller and lighter and can be subjected to a much greater depth of discharge. Compared with a typical lead acid battery which can only be subjected to a recommended depth of discharge of 50% (meaning a 400Ah battery can only deliver 200Ah), lithiumion battery can be subjected to an 80% depth of discharge. Furthermore, the capacity rating of a lithium-ion battery is usually not affected by the rate of discharge – it has the same capacity whether is discharged over a period of one hour or 20 hours. But until recently, lithium-ion batteries were not available in the large sizes needed for boats. Now they are. Mastervolt has two: the MLI24/160 and the MLI2/320. As you might have guessed, these are 24V <at> 160Ah and 12V <at> 320Ah, both equating to 3.84kWh. They weigh just 45kg, 70% less than an equivalent lead acid battery pack and 70% smaller, as well. They have a very long lifespan with greater than 2000 charge cycles and charge efficiency is also much higher than typical lead acid units; 90 to 94% compared to 70 to 83%. The battery packaging provides completely isolated battery terminals and they can be connected in series up to 250VDC or in parallel. OK, so they are a lot more expensive than lead acid batteries but the overall advantages can outweigh the higher cost. You can work with a smaller capacity battery, you get much longer battery life (up to triple the life-span) and overall efficiency is much higher. For further information, contact Mastervolt Australia, 30 Beach St, Kippa-Ring, Qld 4021. Tel: (07) 3283 7800; Website: www.powersolutions.com.au Acknowledgement: our thanks to Mark Whitman and staff at North South Yachting for their assistance in the preparation of this review. SC siliconchip.com.au February 2011  21