Whopper
Active member
Bmw 6 cylinder twin turbo diesels can achieve that in any guise (3,5,6,7,x)..and can better the 7 seconds easily!
Greeline Hydrid
- Thread starter oGaryo
- Start date
Bmw 6 cylinder twin turbo diesels can achieve that in any guise (3,5,6,7,x)..and can better the 7 seconds easily!
LittleShip
New member
Yeh right in your dreams..... My sons X5 does about 15 in town and 32ish on a long run, if you drive at a constant 50 you may get 40 ..... with luck. He's envious of my X type Jag that gets between 48-52 on long runs.
Tom.
MapisM
Well-known member
Yeah, BUT!
The advantages you get with a 100% electric propulsion, feeded by scaled gensets, are more than that.
You can still maneuver, say on a 60 footer, with just one 25kW genset running.
But with no range/duration constraints at all: you can actually cross oceans in that mode, if you don't mind keeping a sailboat pace.
Or you just turn on other gensets, when required to go faster.
And all of this without carrying around tons of batteries.
Not to mention the intrinsic redundancy of the system.
Imho, moving around marinas in stealth mode remains just marketing at its best. But each to their own, of course!
Re. the cars thread drift, I mistakenly said "another 2+ tons car", but I actually meant suv.
And I fully agree with LS, there's just no way a X5 can get anywhere near 35mpg - and neither can the ML or the Touareg, for instance.
Oh, and they are nowhere near as fast either, at least in their economic/diesel versions.
Petrol V8 flavours of course are indeed fast (not to mention the W12, possibly the most impressive SUV engine I've ever tried, way better than even the Cayenne V8), but fuel burn just gets ridiculous with those monsters.
@g_o_g: I must say that I know close to nothing about the RR hybrid, otoh.
I read a short article upon its presentation, but I'm always a bit skeptic about using diesel engines in hybrid cars, so I didn't bother to better understand its details.
Did you have the opportunity to try it - or do you know if it's as good as they pretend it is, anyway?
D
Deleted User YDKXO
Guest
My wife's X3 2.0D easily bests 35mpg on average and she's got a heavy right foot
Hugin
New member
What you refer to is diesel-electric propulsion. Not exactly a new idea http://en.wikipedia.org/wiki/Vandal_%28tanker%29
Add some batteries to the diesel-electric propulsion and you have what is now called series hybrid propulsion.
Yes, I agree this set up would be ideal in many situations, but there are also a few obstacles. Initial costs could be a problem as you add extra system components that probably will be low-volume items for some times = expensive. The problem could be minimized if production volumes were large enough, but how do you assure a market breakthrough if there is initially a significant price premium? Another problem is weight. Not a concern for displacement boats, but adding extra weight to a planing boat initiates a viscous circle where the increased weight need to be compensated by more powerful engines, which adds even more weight and also drives up fuel consumption. Either that or boat owners must accept to lose some speed at the top.
I had an opportunity to tour the GL33 and GL40 in Dusseldorf this year. Greenline's sales rep claimed the 11kWh Lithium-battery in GL33 weighs less than 125kg. Don't know if it's true though, he didn't appear to be well versed in the tech stuff. Anyway, tons of batteries should not be needed. I've played with the idea - purely hypothetical - of using the battery package from Tesla Motors in a boat. 85kWh for less than 600kg weight.
rustybarge
Active member
Toquedo do a 80hp electric outboard, but it works on 400 volts dc.
I'm just trying to imagine all that water splashing around with that sort of voltage, and it being DC your hand would permanently stick to the wire if you got a shock.
IIRC it's also very expensive, double the price of a stanadard o/b, and then you need to buy a genny or batteries, or both on top of that.
When you consider that most modern cars can manage 50mpg, and most boats can't manage 5mpg, I can't see how the concept could work.
MapisM
Well-known member
Oh yes, absolutely.
Semantic aside (Nordhavn used to call it hybrid system, when they gave it a try), that's what I meant.
Back in the days, Dan Streech said “We envision 10 years from now it could be so common that even< 40-foot boats might have it.”.
Now, what he envisioned is not going to happen in a few years, so time will soon prove that his forecast was wrong.
But imho, he got the timeframe wrong, not the principle.
Well, he actually got also a couple of boats wrong to be honest, making a proper mess, with lawsuits etc.
In fact, the "diesel-electric" webpage has been promptly removed from Nordhavn website already years ago.
But the web memory is longer than many boat builders would like, so you can have a look here if you're interested:
https://web.archive.org/web/20080303204017/http://www.nordhavn.com/constr_con/diesel_electric.php4
Not to mention Siemens, which even removed its website completely...:
https://web.archive.org/web/20060822163628/http://www.sea.siemens.com/marine/about/index.html
Bottom line, as of today, neither the diesel-electric nor the traction batteries approaches are making any wave in the boating industry, so to speak. Not even ripples, in fairness.
But if I had to bet which of the two concepts might become interesting in the future, my money would rather go on the first, than on the latter.
Another 10 years, maybe? I'm not holding my breath anyway, in the meantime
GSL
Member
Audi SQ5 ??
kcrane
Active member
Yep, my SWMBO runs a 520d Touring auto. The average mpg for the car over the 12 months she has had it stands at 48mpg, which is a mix of town use and longer runs.
Hard to justify the extra complexity and expense of a hybrid against those sort of figures from a car that also performs more than adequately.
D
Deleted User YDKXO
Guest
I guess the problems are cost and suitability for high speed. As I understand it, the efficiency of a diesel electric hybrid system comes from running the engines at their optimum rpm for maximum fuel efficiency, something which is more useful at low speed when, on a conventional boat, the engines are running at inefficient low rpm. However, on a conventional planing boat at high speed, the engines/props are already configured such that the engines are running close to their optimum rpm so I don't see how a hybrid system could deliver better fuel efficiency, especially since the overall efficiency is worse than the efficiency of a conventional system. So until hybrid systems can deliver significant fuel savings at high speeds as well as low speeds, I don't see that there will be a big market for them in pleasure boats. Then there is the cost. If Nordhavn are approximately correct and a diesel electric system adds 8% to the cost of the boat, then that is another factor against hybrid systems. 8% of a £1m boat buys an awful lot of fuel even at today's prices
rustybarge
Active member
Hugin
New member
Thanks, interesting piece. Confirms the cost issue.
Ouch. It will not be easy to recover that in fuel savings alone. According to a German Greenline dealer's 2014 pricelist the price premium of the hybrid version Greenline 33 is around €18.000-20.000 when adjusting for other differences in equipment. http://www.allertmarin.de/wp-content/uploads/2008/09/GREENLINE-33-PL-I-2014.pdf
Seaway claims to have sold more than 300 of the GL33 and GL40.... about 80% of these are the smaller model. I don't know how many of them are hybrid equipped; probably slightly less than half. Still, it's more than a ripple also considering how the awards have been raining on the Greenline boats since 2010.
Slightly off topic: I stumbled on this regarding the Nordhavn
So going from 149kW to 436kW only gives a speed gain from 9,5kts to 11,5kts?? Sounds wrong, or am I missing something here?
MapisM
Well-known member
I would think that by "takes over" they meant that the smaller genset is turned off.
Anyway, yes, full D boats become exponentially inefficient, as soon as they approach their hull speed.
Horses for courses!
grumpy_o_g
Well-known member
Not tried it yet - demonstrators don't get to the dealers for another few weeks at least. I'm impressed by the dealer's optimism as I actually inquired about new and nearly disc's and they's been trying to flog me a RR ever since. I was thinking of £30-40K not £100-120K!!
I'm actually quite impressed by RR have done as they've not tried to make it an electric car with a diesel engine but gone more along the boost idea - ironically also used by the Maclaren P1 and the new Ferrari Enzo replacement. Given that my diesel seems to drink heaviest when I'm constantly stopping and starting (especially when I'm using all that lovely torque) then a regenerative system that also takes the load off the engine when when you give it a bit of welly seems sensible. If they can get the claimed 40+ mpg out of something weighing nearly 3 tonnes with aerodynamics of a slightly chamfered brick I shall be very impressed.
MapisM
Well-known member
Doh! I missed your post before, for some reason.
Yep, all agreed. Where weight reduction is crucial, plain vanilla diesels are hard to beat.
All my previous comments were mainly referred to D/SD boats, where weight is not so important, and to some extent is even a plus...
Otoh, I think the cost is (mainly) a matter of low numbers, for the moment.
While the diesel-electric systems are overall more complex and require some additional bits, there's also a simplification in some respects - no gearboxes, just as an example.
And if you want to achieve the same level of redundancy with a thermal engine only system, you're also bound to increase costs.
In perspective - I mean, whenever these things will become more popular - I don't think the cost differences will be a big factor.
MapisM
Well-known member
Aha, thanks.
I for one would be interested to hear your impressions, when you'll have a chance to drive it!
D
Deleted User YDKXO
Guest
Interesting articles in this months Passagemaker magazine exploring the pros and cons of parallel and series hybrid systems and based on propulsion efficiency only, there doesn't seem to be much going for them. They calculated crossover points for a particular boat (45ft yacht if memory serves) after which conventional drives become more efficient and these crossover points are as low as speeds of between 3.5 and 4.5kts so if this boat was cruising at higher speeds under power, a hybrid propulsion system would actually be less efficient. They also found that the efficiencies quoted by the manufacturers for their electric motors and batteries were unrealistically high. In their view, hybrid systems don't stack up against conventional drives as a propulsion system alone on boats. Their efficiency could be improved with additional energy sources such as solar panels and wind turbines but the gains would be marginal. They felt that the one area where a hybrid system may be attractive to owners is in supplying domestic power for extended periods without the need to run engines or gennie but IMHO you could achieve the same kind of situation with a smart inverter and larger battery pack without going to a hybrid propulsion system.Doh! I missed your post before, for some reason.
Yep, all agreed. Where weight reduction is crucial, plain vanilla diesels are hard to beat.
All my previous comments were mainly referred to D/SD boats, where weight is not so important, and to some extent is even a plus...
Otoh, I think the cost is (mainly) a matter of low numbers, for the moment.
While the diesel-electric systems are overall more complex and require some additional bits, there's also a simplification in some respects - no gearboxes, just as an example.
And if you want to achieve the same level of redundancy with a thermal engine only system, you're also bound to increase costs.
In perspective - I mean, whenever these things will become more popular - I don't think the cost differences will be a big factor.
They also made the point that the boating industry has enough problems building and maintaining reliable conventional drive systems and that complex computer controlled hybrid systems may be beyond many yards to install and maintain properly. The author of one of the articles also refers to his having to supervise the removal of a hybrid system from a 70ft boat and substitution with a conventional drive system and I guess that refers to the Nordhavn 72 already mentioned
As for Greenline having sold 300 of their GL33 and 40 boats, I take that with a very large pinch of salt. Most established manufacturers don't sell anywhere near that number during the whole life cycle of a particular model
MapisM
Well-known member
Spot on.
The technology proved to be beyond the competence of even a builder with a decent reputation like Nordhavn, back in the days when they tried the system. And I would think it still is, tbh.
But these things change over time, of course.
As happened with ships, where diesel-electric propulsion is now rather the norm than the exception.
Though of course, on ships there's a Chief Engineer, an ETO, and so forth...
And to be fair, the 24/7 electric power demand is huge on ship also for services alone.
Which is another advantage of modular gensets running the whole vessel.
Btw yes, I also read somewhere that one of the two Nordhavns they built was reconverted to straight diesel.
As I said, it's not a coincidence that they removed any reference to that experience from their website...! :ambivalence:
Bottom line, nope, I also would not even consider "hybrid" stuff of any flavour, if I were speccing a new vessel today.
But in the future, I think it's a technology which is bound to return.
...though I can predict anything but the future, of course!
PS: Lovely new avatar, M.!
Hugin
New member
Indeed http://www.steyr-motors.com/marine-diesel-engines/2-4-and-6-cylinder/integrated-flywheel-generator/
But here the point is that once you decide to go for an enlarged alternator/inverter and larger battery pack you might as well add an electric motor + controller to the mix for relatively little extra money. Depending on the set-up of the system you can potentially gain the following advantages.
- Limited-range silent low-speed cruising and maneuvering/docking
- All reversing can be done in electric mode, eventually eliminating the need for a reversing gearbox
- Acceleration boost to get up on plane. Electric motors have tremendous torque at low revs; exactly where diesel engines are weak
- Very fine control at low speed and for maneuvering; in principle from 1rpm. Trolling valves for diesel engines become superfluous
- For single engine installations you get a limited battery-electric limp-to-nearest-port capability in case of main engine malfunction. Granted, it's a limited capability, but it is better than no capability
I don't think this is a valid point. Future hybrid systems would most likely be shipped from propulsion manufacturers ready to plug n' play. Take pod drives as an example. Would or should boat manufacturers try to merge a Volvo engine to a ZF pod and a Mercury controller? Of course not. Pod drives are the so far most complicated propulsion type intended for leisure boats, but from the boat builders' point of view installing the power drive line was never easier, because the whole package comes as plug n' play from one supplier, who has invested significant resources up front in perfecting the package.
Why? Seaway is among the big players in the industry..... claiming false sales numbers would surely come back to haunt them sooner rather than later. Beneteau claims to have reached hull #200 of their 5 times more expensive Prestige 550 and 550S models in an even shorter time-frame. Bavaria claims to have sold more than 100 boats during just the 9 days of the Dusseldorf show. In that light 300+ boats (available from just €120.000 inclusive German VAT) in 4+ years doesn't seem an excessive claim. What can be questioned is how many of the boats are actually hybrid equipped and how many are sold as cheap and spacious floating real estate
Hugin
New member
Inventing/developing new propulsion systems is not among a boat builder's core competences.... as was vividly demonstrated by Nordhavn.
If the hybrid system came from Volvo, Mercury or another propulsion expert then issues with technology would - in an ideal world - be weeded out before the system is even marketed. In the real world the early adopters are of course often used as crash test dummies until all problems are rectified, but in the end the vast majority of users should not experience any problems due to more advanced technology being adopted.