Solar boating

[CaptTom]

+1 on everything Marin said. There's technically possible, and then there's practical. It's technically possible to go to the moon.

Still, this topic is very interesting. Has anyone done the math? I mean, how much solar energy falls on a reasonable-sized boat, and how much energy does it take to run a reasonable suite of propulsion, heating, air-conditioning and refrigeration systems?

 

[Underway]

Yes, a "bucket" is a good idea. Or if enthusiasts want to delve into the details, deckofficer provided the thread link (above) to the Cruisers forum where the subject has been covered in mind boggling technical detail, and includes the inevitable debate between skeptics and supporters. Like it or not there are political undertones inherent in this technology.

 

[rjtrane]

What Marin misses out on is that none of us working in the energy-efficient area are proposing to replace go-fast boats or claim a big segment of the market. Yes, most boaters want to go fast. But, there remains a significant segment of boaters used to going slowly (sailboaters) reaching retirement, fixed-income ages (baby boomers) that will buy slow boats. Look at the continued sales of Kadey-Krogens and Nordhavns.

Another interesting thing about boat building that many miss out on is that this industry is not dissimilar to the automobile industry in its infancy. It takes a minimal amount of capital to start building boats - Yes, there are the big companies out there mass-producing boats for the bulk of the market. But, in Maine, there are boat builders that build a hand full of boats each year - 1, 2, 3 or so - and make a profit. These builders are not "tinkerers" but building for a select group of buyers.

Let me say again, NONE of us is trying to convert those who live in dark areas (Pacific Northwest) where the sun shines once or twice a year - or those who actually have jobs and need a quick boat to get out to the Gulf Stream for a day's fishing - or those who don't really care about spending several hundred dollars a day to push their 50 footer at 30 knots. They will NEVER buy a slow boat, much less one using renewable energy.

Fuel cells have some potential. I worked on a Department of Energy grant with Florida Institute of Technology to do a "demonstration" project using a fuel cell for "hotel" loads on a yacht. Searay had already walked away from the project when we were asked to join with FIT. After months of research we sourced all the parts to make it work, including hydrogen generators from Proton Energy Systems - our goal was not only to power the "hotel" loads but to make the hydrogen on board AND propel the boat.

Interestingly, in order to generate enough energy from our amount of solar to actually make the hydrogen from sea water (first turn salt water to fresh), we had to store it temporarily in a LiFiPo battery - then invert to AC power to run the hydrogen generator. But, we felt we could make it all work on the budget proposed by the grant. Unfortunately for us, we never found out. FIT yanked the proposal and decided to get a research grant in place of the demonstration one.

But, it got us to thinking - one way to have a solar boat that could perform would be to have a solar farm land side producing the power to make the hydrogen that would power the fuel cell(s) on the boat. Only works if you have a fair amount of real estate (like your factory roof) for the solar.

From my understanding, making hydrogen from water is energy intensive so you need a low-cost source of energy - wind - solar - water. Or, you can make it from petroleum, which does defeat the purpose of using less of the finite source of petroleum in the earth. The marketable reason to do this is, of course, pollution - a fuel cell does not pollute whereas diesels and gas motors, do.

Interestingly, Green Line, a boat builder in Slovenia, has enjoyed success with its hybrid-powered yachts - which have some solar on the overheads. There are others, doing the same in smaller ways.

Even though the Green Lines (and others) do not produce enough solar to cruise in "real time," they do produce some energy from the sun which is then stored in LiFiPo cells for future use. Any use of this stored energy means less fossil fuel burned - whether it's just to power the fridge or take a 4 knot cocktail cruise around the harbor on electric power. I feel that this is a good thing.

I feel what I am most advocating here is that the use of ANY renewables (wind or solar) is a step in the right direction. And, if a yacht can be built that can cruise on renewables alone, that is definitely a step in the right direction.

With the plethora of baby boomers reaching retirement age - many of whom are getting out of sail - a slow, energy-efficient cruiser may have some appeal. Electric boats are not aimed only at the "techies." The goal is to make them as effortless to use (actually more effortless) than your traditional diesel-powered yacht. This can be from the little things like no switch-over of power when leaving the dock to motor maintenance (virtually zero with an electric motor) to simplicity of steerable pod drives.

Yes, you're not going fast - yes, you're daily cruising miles is limited - yes, the boats need to be lean and light - but, with all this said, there are folks who will find this silent, fuel-free cruising a delight. Certainly not all - not those in the northern climates (BTW, it is my understanding more retirees head south than north?) - not those who want to transit the North Sea. But those who enjoy quiet (read: "silent"), energy-efficient, cruising.

 

[sunchaser]

Yes, most boaters want to go fast. But, there remains a significant segment of boaters used to going slowly (sailboaters) reaching retirement, fixed-income ages (baby boomers) that will buy slow boats. Look at the continued sales of Kadey-Krogens and Nordhavns. Correct


Let me say again, NONE of us is trying to convert those who live in dark areas (Pacific Northwest). Rather than trying to convert those in the dark areas, why not say solar is not feasible in the Northern climes with today's technology?


(BTW, it is my understanding more retirees head south than north?) - not those who want to transit the North Sea. But those who enjoy quiet (read: "silent"), energy-efficient, cruising. It is amazing how many boaters and boats there are in the PNW and NE US who are from the South. Count me as one. I had a choice and boating in FL or CA does not compare.

Reuben

On a marketing, resale and technical basis, why would a big center hull tri of say 70' be better than a mono hull like an Outer Reef, or even as good? Both are destined as blue water cruisers.

 

[Marin]

Reuben--- I agree with your post and that there is a market for the kind of boat you propose. The challenge is that since that market is very small-- and I believe you are overestimating its size considerably for a number if reasons-- how do you make a very small number of boats using fairly expensive technology at an inexpensive enough production cost to make them affordable to that market?

There are plenty of exceptions, but all the people I know who are sailboaters who have changed over to power as they age are people of modest means, most of them retired and on somewhat fixed incomes. When they buy a powerboat they spend perhaps $50,000 to $100,000. Yes, there are wealthy exceptions. But the few I know or know of bought large, fairly fast boats because they are no different than the vast majority of us--- they want to carry a lot of "stuff" including friends, sons and daughters, grandkids, etc. and--- they want to go reasonably fast.

No question there are people like yourself and deckofficer who desire a low energy, super-efficient boat, which if it's electric means light, very slow, and with a short range, at least with today's technology. But that market I believe is really small which creates a vicious cycle, so to speak. The market is small, the cost is high, which in turn makes the market even smaller, which pushes the cost even higher, and so it goes.

Which is why I believe this concept will never grow past the enthusiast, one- off, create it yourself stage. As I said earlier, I think there are energy sources "out there" that once discovered will give us the abilities most of us desire--- as big as we wnnt, carry what we want, go as fast as we want, and go as far aswe want. This has been the pattern throughout history. Horses, steam, petroleum, and whatever comes next.

 

[deckofficer]

Well, I'm on board with what Reuben said (no surprise) about the marketplace, current technology, and the desire for clean, quiet cruising. I am a sailboater, so a solar powered boat that can knock off 100~150 nm 24 hour runs suits me fine. Take a look at the simplistic design of the Atlantic Sun 21






This above is nothing more than a heavy C60 commercial cat ferry converted to solar electric, outfitted with 10 Kw of solar panels and AGM lead acid batteries that crossed the Atlantic running at 5.5 kt or 130 nm 24 hour daily runs. If something like this could be built and sold for under $300K new, which I'm sure it can, I'm in. I like the totally flat deck between the amas, where beach chairs and portable tables can be configured for visiting guests. A central wet bar, fridge, BBQ and storage for the deck furniture would be nice. One hull for galley, inside settee, and nav station, the other for berths and head/shower. Nothing fancy, just usable. In good weather at anchorage you entertain guest outside on the flat deck, in lousy weather other boaters have you over in their enclosed salon.

Reuben, could you copy the above boat, making it lighter, and sell for $250K?

 

[sunchaser]

As I said earlier, I think there are energy sources "out there" that once discovered will give us the abilities most of us desire--- as big as we wnnt, carry what we want, go as fast as we want, and go as far aswe want. This has been the pattern throughout history. Horses, steam, petroleum, and whatever comes next.

Marin, you are 100% correct, in the opinion of NASA, the Russian Space Federation and college Physics Profs. The greatest source of "interesting" and unlimited energy is earth's magnetic field. The magnetic field is the reason we can survive here, it deflects the radiation from space and moves much of it many tens of thousand of miles outside the earth allowing life as we know it to exist. Otherwise we would be radiated in no time as if we were sitting on top of Chernobyl when it let go.

The earth's core is molten metal with the outer layers of earth rotating around this mass, creating a force field similar to the effect of a rotor and stator in an electric motor. Or some similar more complicated explanation I will let more astute than me lecture on -think Gaussian fields.

 

[deckofficer]

There is always cold fusion we have yet to master.

 

[Marin]

Reuben and Bob, don't get me wrong. I don't think tinkering with solar-powered electric boats is a waste of time. Many of our best technologies have been stumbled across while someone was doing something else. The classic example, at least in the popular but undoubtedly fictional story, has Thomas Newcomen boiling water for a cup of tea and as he watched the steam come out he realized there was energy there that could be used to do work. (Sometimes this story is attributed to James Watt but he came after Newcomen, who designed and built the first practical "atmospheric" steam engines.)

Given that people had been messing about trying to harness steam long before Tom came along, the real story of how he got interested in steam is probably far less Hollywood than watching a teapot. But the point is that there are many examples of people attempting to do one thing and realizing there was an even better way to do the same thing.

So experimenting with solar may very well lead someone to figure out how to harness a totally different form of energy that's more efficient, powerful, etc.

Two of my recent projects for Boeing had to do with just that. First in China and then the other month in Brazil we shot technology research projects that Boeing is involved with or interested in becoming involved with covering a range of technologies from biofuel to RFD to organic composites (as opposed to petroleum-based composites). We shot a small airplane designed and built by students in a university in Brazil. The plane is made of organic composites and it currently holds the world speed record for this type of plane.

So pushing the boundaries and trying new things is always good. Some will fail, some will work, and some will work but not be practical to adopt on a world-wide scale. But it's all worthwhile.

My own belief is that the solar-boat idea falls into the last category. It works, but is not practical on a large, producible, affordable, marketable scale because it does not offer what the bulk of the boating market wants or will continue to want. And that will keep it in the one-off, home-built category. But that is not the same as saying it's a waste of time to try to make it work. Because who knows what might be learned or discovered in the process?

 

[deckofficer]

Marin, I understand your point and accept it. Among power boaters, the vast majority want speed to meet schedules dictated by the working life of returning to port at the end of the weekend and then work on Monday. Among sailors that are working, the same constraints apply. But among full time cruisers, solar works now in the perfect scenario of say Caribbean cruising where your passages are less than 200 nm and then your on the hook for a week, soaking up energy from the sun. An ocean passage just means you will need a higher harvest rate of solar energy, and there are a few out there that can cross oceans now on solar. It is this small market that IMHO will grow as we baby boomers set out on a cruising lifestyle for our retirement. Should our retirement income be such that we can't afford a $2 mil Dashew offshore FPB and the fuel to cross oceans, solar or sail is the viable option. For us that have sailed long passages and have been caught in the middle of the night with too much sail up, solar looks pretty good. Not to mention a sailboat doesn't always have winds or wind in a desired quadrant, so on comes the diesel. The main idea I want to get across is with solar you collect energy over a period of time, store it, and then use as needed either for propulsion, domestic loads, or the charging of smaller craft like electric dinghies, kayaks, Segways, and those neat little Sea Doo underwater scooters. Life is so much easier powered by electricity.

 

[Marin]

Life is so much easier powered by electricity.

I certainly agree with that. The ideal boat to me in terms of its propulsion system is electric motor drive for the prop(s)-- water jets are cool but there's an awful lot of energy expended for the return-- and some physically small, self-contained "box" for the generation of the electricity for the motor. So you can size the "box" and motor(s) to power a big boat with it, a small boat, you can go as fast as the hull design will let you, you can cross oceans at speed if you so desire, and the propulsion system puts no limitations on the design of the boat. It doesn't have to covered with ugly panels or whatever.

Of course one of the best things about electric power--- vehicles, boats, trains--- is the almost instant availability of all the power the motor can produce. If someone could build a practical Formula 1 car that was electric drive it would clean up. It could out-accelerate everything else and if you put a Chinese driver in it, it would outmaneuver everything else.

This is a diversion from boats, but my favorite illustration of the incredible acceleration possible with electric drive occurred in the 1940s or 50s in the Green River valley between Tacoma and Renton in Washington. It happend on the Milwaukee Railroad, a perpetually bankrupt but very innovative railroad that in 1915 electrified its 400 mile division through the Rocky Mountains and its 200 mile division through the Cascade Mountains in Washington. Even back then, electricity offered a lot of advantages to rail transportation that I won't go into here.

General Electric and Westinghouse built a variety of electric locomotives for the Milwaukee Roads electrified divisions. Five of GE's passenger locomotives were called "Bi-Polars" (photo) because the axles of the locomotive were also the amatures of the drive motors. So no gear box from motor to axle as most electric and diesel-electric locomotives have. The axle was the motor.

One evening at one of the freight stations in the valley, some brakemen were teasing a Bi-Polar engineer about his locomotive for some reason. The engineer bet that if the two brakemen stood by the front of the locomotive (which was not coupled to a train) he could open the throttle and by the time the rear of the locomotive reached the brakemen it would be going too fast for them to get on.

We are talking a locomotive that was 76 feet long, ten feet wide, and weighed 457,000 pounds (228.5 tons).

The firemen took the engineer up on his bet so the engineer climbed into the cab, raised the pantograph, and when all the cooling fans and whatnot had stabilized "firewalled" the throttle. And try as they might, the firemen could not get hold of the locomotive well enough to climb on as the back end passed them. They tried it several times, and each time, from a standing start, the Bi-Polar would simply be going too fast for them to climb on by the time the back end of the 76-foot long locomotive reached them.

So yes, electricity is a wonderful way to power things.

 

[deckofficer]

Know what you mean, all available torque at 1 rpm. This not so innocent creation of mine could out accelerate my Corvette to 40 mph.
Etek motor, 48 volt AGM bank, 400 amp controller gives 20 Kw at launch.

 

[portager]

I think it is informative to consider the specific energy (energy per unit mass) and energy density (energy per unit volume) of a fuel source or energy storage material to gain perspective. Here is a useful link Energy density - Wikipedia, the free encyclopedia to a Wikipedia table comparing specific energy and energy density of various storage materials. You will note that gasoline and diesel fuels specific energy is ~46 MJ/kg and energy density is ~36 MJ/liter, while lead acid batteries are 0.17 MJ/kg and 0.34 MJ/liter respectively. Therefore, diesel provides 270 times the specific energy and 105 times the energy density of lead acid batteries. When you take into consideration that most trawlers carry 10% to 15% of their gross weight in fuel, increasing the fuel weight by a factor of 270 isn't feasible. This illustrates that to make an electric boat work your design must be much more efficient, or settle for much lower speed and/or range or devote a much larger portion of the payload weight to energy storage or some combination of all of the above. I'm not saying it can't be done, I'm just saying it is going to be very hard and your going to have to make a lot of compromises such as lighter weight, efficient hull form, reduced speed and reduced range.

If you choose to use higher performing/cost Lithium batteries, the specific energy is 1.8 MJ/kg and energy density is 4.32 MJ/liter so diesel is still 25 times higher specific energy and 8 times higher energy density than Lithium batteries.

 

[deckofficer]

A company that slipped under my radar due to my preconceived notion that it was basically an inland lakes boat is the Greenline series. I've seen a few for sale used on Boats.com even though they are new on the market since 2010. I also dismissed this boat because as a mono I thought it was going to be heavy and have an inefficient hull. I was wrong on all assumptions. They build a 33', 40', 46', and 70 footer. I now know a mono can be both cured of rolling, and have an efficient hull after computer-based studies and simulations using CFD (computational fluid dynamics) and Velocity Prediction software, a full range of tank testing trials are performed for the design. Have you ever heard of twin sacrificial stabilizers? I hadn't but what a great idea, using a pair of underwater hull mounted fins, again designed by all those powerful software programs, that does the jobs of both flopper stoppers when at anchor in a rolling anchorage and those failure prone stabilizers when in a rolling sea state.

On my inland lakes misconception, I was wrong there too after seeing their usage across the Tasman and in the North Sea. I've spent a lot of time in the North Sea, any 33' power boat out there has to be seaworthy and built strong.

It has a forced air cooled 1.3 Kw solar panel, 11.5 Kw-hr of lithium batteries with an electric range of 20 nm @ 4 kt. To give you an idea how much that battery bank can be expanded, Reuben upgrade to 52 Kw-hr bank, so his bank in the Greenline 33' would give it a range of over 90 nm. Slow down to 3 kt, should be able to run 24/7 on solar output.

Upon further research I have discovered they have sold 100's and employ 250 workers.

I'm going to post some pictures, curious for input, and if you would call it a boating bargain at the selling price?

 

[Marin]

Nice looking boat. Very good combination of traditional design aspects and modern elements.

I assume the solar/electric power is an auxiliary propulsion system to a diesel? The at-speed photo I'm guessing is not trying to imply the boat can do this on electricity alone.

What are the asking prices for the 33 and 40?

 

[deckofficer]

I'm not sure what they sell new for, but have seen a used price range on 1~3 year old 33's from $175K to $260K. Your right, diesel electric. Diesel is 165 hp VW down to a 75 hp VW. Electric motor is 7 Kw output and 5 Kw generator when driven by the diesel. Top speed 16 kt on diesel, 6 kt electric.

 

[Marin]

Well, judging only from the photos and assuming the 1 to 3 year old boats were well looked after, the prices you quoted seem in line with reality to me.

 

[deckofficer]

They must be hitting a chord with the boating public. Besides the 19 industry awards, they sold over 200 of the 33 footers in the first 18 months. I guess in countries that have $8~$12 a gallon fuel costs, a cruiser that gets 16 nmpg at slow diesel cruise and free nm on electric is going to be popular. What is interesting about the design team and location, Solvenia with only 47 km of shoreline, is this team and location is the hot bed for tank testing and costly software development. I kind of like the idea of the fat cats paying for all this for yacht racing and commercial shipping and us lowly pleasure boaters reaping the benefits. Explains why for 2 years running, the Greenline 33 holds the #1 slot in production numbers of 10 m boats.

 

[Marin]

Yes, I can understand their popularity even if they didn't have the diesel-electric/pure electric propulsion. It's a very good looking boat by my standards, which has been my beef all along with so many "efficient power" machines, be they cars or boats. The Greenline shows that you can put a practical, efficient propulsion system in a very good looking package.

Thanks for bringing this boat to our attention. While we are not in the market for a different boat and may never be, if we were to start considering a different boat I would definitely add the Greenline to the short list of contenders. Which now has three boats on it instead of two.

 

[deckofficer]

Yes, I can understand their popularity even if they didn't have the diesel-electric/pure electric propulsion. It's a very good looking boat by my standards, which has been my beef all along with so many "efficient power" machines, be they cars or boats. The Greenline shows that you can put a practical, efficient propulsion system in a very good looking package.

Thanks for bringing this boat to our attention. While we are not in the market for a different boat and may never be, if we were to start considering a different boat I would definitely add the Greenline to the short list of contenders. Which now has three boats on it instead of two.

With your rep on TF, that is some serious praise. You probably shouldn't consider a Greenline because at their current sales rates, 5 years down the road you would have a boat just like everyone else. Wait a minute, you have a Grand Banks, so you do go with proven designs and boat builders.

 

[Marin]

A good design (that we like) is a good design. It doesn't matter how many others are out there. Other than the Greenline which is certainly worth considering, there are only two boats we are considering replacing our old GB36 with if we opt to go down this path in the near future. The Fleming 55 and the Grand Banks 46, with the Fleming the most likely candidate.

Both these boats are a dime a dozen up here so regardless of which one we got we would certainly not stand out in a crowd, just as we don't now.

 

[RickB]

I now know a mono can be both cured of rolling, and have an efficient hull after computer-based studies and simulations using CFD (computational fluid dynamics) and Velocity Prediction software, a full range of tank testing trials are performed for the design.

And just how did you think virtually every modern (post 1960) concept is designed?

Have you ever heard of twin sacrificial stabilizers? I hadn't but what a great idea, using a pair of underwater hull mounted fins, again designed by all those powerful software programs, that does the jobs of both flopper stoppers when at anchor in a rolling anchorage and those failure prone stabilizers when in a rolling sea state.

Put down the Kool-Aid jug for a while and do a little reading on yacht design over the past 20 or more years. Fin stabilizers are about as common as wet exhaust systems and I can't think of a single one that can't be described as "sacrificial."

Just because they point downward doesn't mean they work any differently than the first ones installed on a ship in the early 1930s. And the fact that they are mounted so far aft on that boat probably means they don't work nearly as well.

Do you have any idea of how much power it takes to operate a pair of fin stabilizers? Do you know how much drag they induce? Do you know how (in)effective they are at what amounts to idle speed? And finally, do you know how (in)effective a single pair of small area stabilizers mounted aft will be for zero-speed stabilization?

Greenline's marketing is obviously very effective when the recipient arrives at their doorstep from the path of feel-good greenyland and without much knowledge of state of the art vessel technology, energy requirements, and performance expectations.

That boat would probably make 3 knots over the ground from windage alone. That is great if you operate it inside the marina breakwater to dock it but I suspect a breeze too light to fly a kite and a chop large enough to stop the radio control boat hobbyists would reduce the distance made good to minus figures.

The type of operation where that boat might be attractive is the same operation and location where nearly any low powered, lightweight, TT type of boat will do as well for half the price and probably three times the reliability. It would probably impress the SF Bay and Delta dayboat crowd on a calm day but other than that I see a lot of smoke and mirrors marketing.

 

[rjtrane]

70 Footers

Reuben

On a marketing, resale and technical basis, why would a big center hull tri of say 70' be better than a mono hull like an Outer Reef, or even as good? Both are destined as blue water cruisers.

Not sure why this question is asked? My guess any well-engineered, well-styled, well-built cruising yacht of this size could do OK in the market if competitively priced. I have no horse in this race.

On the other hand, if one wanted to propel a 70 footer with solar-generated energy, then perhaps a long, lean center hull with a pair of skinny amas would be the preferred platform - of course, the accommodations of this 70 footer may be more akin to those of a "normal" 50 footer? And to find a market, the price would need to be closer to that 50 footer, also.

What many ignore is that the cost of building a boat is tied to the weight of the boat - it's like buying steak, you pay by the pound. Of course, prime beef (high tech) costs more per pound. Just compare the price of an MJM with that of an Island Gypsy to confirm the costs/pound of high tech construction.

In the 30 foot "trawler" area (i.e. Ranger Tug), I see no reason why a solar/electric boat can't be built with similar accommodations and priced to compete. It may be longer and leaner - perhaps a bit more spartan in finish (wood is heavy) - but with equivalent space and function minus the speed (and costs of maintaining a diesel and filling up fuel tanks).

 

[rjtrane]

Bob has posted some photos of the Greenline 33 and 40. Price for the 40 is a bit over $500k. I have been aboard both boats and am impressed by the ingenuity of their design team. They have "cracked the code" on a convertible master - the V-berths can swing inboard to become an island queen. On the 33, the helm seat flips back to become part of the dinette. The aft galley has a disappearing window opening onto the aft cockpit like a snack bar, joining the interior and exterior spaces.

Fit and finish is good though a bit "Ikea-like." Not to every American's taste. I have NOT been out on one - it is my understanding that the e-propulsion is typically used for maneuvering and of course, cocktail cruises.

Slovenia seems to be a hotbed of hybrid activity. The Iskra motor/generators that Greenline uses coupled to VW diesels are the same we have on board Sunshine coupled to the Steyr diesels. There is a boat builder making a solar launch using a single 4kW Torgeedo (hidden under a seat) for power. Likewise, some of the more interesting steerable electric pods are coming from Slovenia.

I applaud the effort and execution that Greenway has achieved with their hybrid cruisers - and I'm more than a bit jealous of their success.

Interestingly, however, I recall posts on this forum saying that most current buyers of cruising yachts are 1) looking to spend between $50k & $100k (obviously in the very-used boat market) or 2) going to spend hundreds of thousands on faster yachts. I'm wondering why any of us is even thinking about fighting this trend? BTW, the Greenline has very modest speeds, mid teens at most. And as noted elsewhere, are selling a bucket-load of them! They certainly must be doing something right.

 

[deckofficer]

RickB,

It appears I was having to stand in line to drink the Kool Aid. When a new entrant to the race takes pole position by selling more 10 m boats than all the others, the Kool Aid (hype) didn't disappoint. A small note, as a styling cue, added on solar panels look a bit retrofitted, whereas flush panels are just a color cue. To bring back the higher efficiency of a cooler panel they employed forced air circulation under the panel. The stabilizer fin is designed to break away with no damage to the hull and replacement fins are inexpensive.

I know we have had tank testing for many decades, but only in the last 15 years have we had computers that are fast enough to run these software programs. Remember when CAD first arrived and how it taxed the computers back then. As a teenager in the 60's I remember reading all the boating magazines and being drawn to the fuel consumption curves for the boat tests, thinking I could only afford this boat at idle. Fuel was cheap back then and the design software or computers to run them weren't available. Today things have changed, tomorrow solar boats will be common place.

 

[RickB]

It appears I was having to stand in line to drink the Kool Aid.

That's the beauty of a Kool-Aid stand, people will stand in line to drink the stuff. That is why they call me-too marketing "drinking Kool-Aid."

Aside from subtracting 5 years from the design timeline and claiming that replacement of a broken off stabilizer is "inexpensive" (haven't had to replace one, eh?) aren't there any comments about the power requirement and effectiveness of those peculiarly located "stabilizers"?

Idling along at 3 or 4 knots at slack water on the New River in Fort Lauderdale or a similar situation might be romantic and interesting for the first couple of weekends but spending a half million $ should provide the buyer with a lot more than an Ikea interior and barely enough power to get out of the slip when there is a hint of current or a light breeze.

Not meaning to rag on you particularly but the aquatic hybrid MMS here that seems to focus on the minutiae of milliamps and nano watts should perhaps apply that same microscope to the realities of how that boat is equipped and how much power it really takes to use the stuff that you waxed so generously about a couple of posts back.

Now that you know fin stabilizers exist, figure out how much power they use and why the claims you stated are maybe a bit clouded by some Hickory flavored Kool-Aid.

 

[Tad Roberts]

Even though the Green Lines (and others) do not produce enough solar to cruise in "real time," they do produce some energy from the sun which is then stored in LiFiPo cells for future use. Any use of this stored energy means less fossil fuel burned - whether it's just to power the fridge or take a 4 knot cocktail cruise around the harbor on electric power. I feel that this is a good thing.

Far too much going on here for me to keep up with, and for that I apologize. But it's all very interesting.

Reuben,
Does not the above scenario ("any use of stored energy") ignore the real additional cost of that stored energy? I'm thinking of the real environmental costs of manufacture, acquisition, maintenance, and recycling of batteries, solar panels, electric motors, etc. And the additional power required (increased displacement = increased resistance) to move all this additional equipment every time the boat moves.

That's my take on the relatively high-speed hybrid Greenline.

In other situations a purely electric vessel is starting to make some sense. I'm working on an electric "Great Circle" boat right now that may work. What it comes down to is range and reserve power. With perhaps 800 pounds of batteries (I'm guessing at Lifepo) plus solar panels to charge them equaling a gallon of diesel fuel(in terms of deliverable energy), silence and not burning fossil fuel comes expensively.

 

[deckofficer]

I think they are passive stabilizers.


As to other power requirements, i.e. galley, lights, electronics, etc, 1.3 Kw of solar will handle all of that with extra left over for topping off the propulsion battery bank. You have to get in a mind set of slow is good, which if your full time cruising works fine. When I was full time, passage making was maybe 10% of my time spent on the water, hanging on the hook was the other 90%, so a slow and steady collection of solar energy that is stored in lithium batteries works.

 

[Marin]

Aside from subtracting 5 years from the design timeline and claiming that replacement of a broken off stabilizer is "inexpensive" (haven't had to replace one, eh?)....

Back in the early 90s Grand Banks built three GB66s. These boats have no relation whatsoever to their Aleutian line. The GB66 was in essence the plans of a GB52 enlarged on a Xerox machine to sixty-six feet.

Besides being ugly--- in my opinion the GB Europa design doesn't hold up well past 52 feet and even then it's starting to look a little awkward--- the GB66s were not very stable due in large part to the owners insisting on a fully-enclosed, by which I mean solidly enclosed--- flying bridge. So what would have been an open flying bridge became a very heavy pilothouse.

Now I'm sure the boat had to meet whatever stability requirements are set by whatever regulatory agencies set them-- the USCG, I suppose, in the US--- but they were definitely pushing the envelope.

Active stabilizers were essential to these boats and I was told by one of the shipwrights who was part of the commissioning crew for one of them that the stabilizers were required to be on whenever the boat was underway.

One of these GB66s was part of a Grand Banks-sponsored group-cruise to SE Alaska. Somewhere north of Prince Rupert, IIRC, the GB66 tore one of its stabilizers off on a rock. As I heard the story the boat was just barely saved from sinking by the action of GB's very experienced leader of the cruise who managed to get the major water inflow stopped.

The boat returned to Puget Sound where it was repaired. I was told the cost of the repair and it exceeded what we paid for our boat. The point being that ripping something like an active stabilizer off the bottom of a boat is not a "just stick another fin on it" repair.

PS-- I wrote the above before seeing the photo of the Greenline boat's fin. They are indeed passive, which means they won't do all that much to control rolling. Their function is the same as bilge keels. They add some resistance to rolling but they will not be nearly as effective as active stabilizers. And they will add considerable drag given their size.

 

[RickB]

I think they are passive stabilizers..

Then they are not stabilizers, they are a bizarre form of drag inducing bilge keel.

That boat is far from the sort one would use for "full time cruising" or "passagemaking."