Future Hybrid Catamaran Cruiser

[Becaris]

I'm taking a look at 'near' future technology as applied to a catamaran cruiser. What I mean by 'near' is technology that has been announced, but is not yet commercially available, and how that technology could be used to improve a hybrid sailing yacht.

First off, there have been some recent breakthroughs in solar panels. These 'thin' panels are lighter and they claim they are cheaper to manufacture (therefore cheaper to the consumer). Right now the only issue is efficiency, but so far each year they have improved efficiency on this technology.
http://www.eetimes.com/news/latest/showArticle.jhtml?articleID=212201094
Simply projecting the improvements forward it is somewhat safe to assume that we will have commercially available thin solar panels in the next few years. Once these new lighter panels are available why not use a Catamaran (with the large deck surface area) and design it to handle quite a few of these light panels? An array of 54 panels that each put out about 200 watts would get you a around an 11 kWh array.

But thin panels isn't the only breakthrough. What about that problem of 'angle efficiency'? On a yacht creating a mechanism to angle your panels to the sun is too heavy and problematic. But, another new breakthrough in solar panels might deal with this. A technology that captures 30% more light at more angles has been announced.

http://www.greentechgazette.com/index.php/solar-energy/solar-panel-breakthrough-captures-96-21-percent-of-light/

Assuming a catamaran of about 50', with two electric motors for propulsion, I wonder how fast it could motor using power right off an 11kWh array? However, that's only good during the sunlight, which brings up batteries. Right now the problems with batteries are weight and price. However, there are already some new lithium batteries out that hold three times the energy of a typical lead acid batter at the same weight. They are currently hideously expensive ($8,000 by some reports) but as we all know, technology prices drop like an anchor, so we can expect more reasonable pricing in the near future.

http://www.examiner.com/x-4427-Houston-Boating-Examiner~y2009m3d1-The-latest-marine-technology-and-gadgets-for-boats

Additionally, there is a LOT of competition right now in the area of efficient lighter batteries due to the push for hybrid and electric cars. There is also that breakthrough from MIT that allows lithium batteries to take on a charge MUCH faster (though this might not help a yacht situation away from a marina).

So assuming we get cheaper, lighter batteries to go along with our new solar panels in a few years, how does that change the landscape in designing a yacht to use these emerging technologies?

If we were to create an 11 kWh solar array, and have sufficient battery storage to run off fully charged batteries for several hours, why not then design a catamaran to only use diesel fuel in emergencies? I'm currently designing/dreaming of a biplane rigged catamaran (I like the redundancy, safety, ease of use of twin un-stayed rotating masts with In-boom furling for a shorthanded yacht). The yacht would have twin motors rather than diesel engines. While sailing the solar array can charge the battery bank, and when needed you can use the motors (in reverse while sailing) as generators to help charge the batteries. When more power is needed or during nighttime the motors can run off the battery banks. During the day when sailing isn't possible they can run off the solar array and/or batteries as needed. There will be a diesel generator for emergencies (foggy day, no wind, power depleted, got to move). However, baring that rare circumstance the yacht should be able to move via wind, solar and/or battery 99.9% of the time, requiring very little diesel consumption, or none.

I'm planning to start building my yacht in a year or two, with a two year build time. That puts it three to four years out from now before it gets wet. I'm planning on using emerging solar and battery technologies that will hopefully be commercially available by the time I'm ready, though the yacht isn't dependent on them.

The idea of a hybrid cat is not new, there are hybrid cats out there right now, but what IS new is using a MUCH larger solar array (due to lighter more efficient panels) and more battery storage (due to lighter batteries). This just isn't currently possible, the weight of the panels and batteries is too much. But with these new breakthroughs improving those areas, can might finally make a yacht that can dispense with regular diesel use.

What am I missing here? What are the issues? (other than we're waiting on the commercial release and drop in price of these technologies).

I have questions for those in the know. For a 50' cat, how much sustained power does it take to move what weight catamaran at what speed? Any estimates? What size motors would be best? Can a larger motor be used with lower current? (Example can a 20 kWh motor be run on 6kWh power from a solar array? The idea being that there would be a diesel generator that could put out much more power for emergency speed, but most of the time the motors would need to run off solar and/or batteries at lower power.)

There is a hybrid yacht out there right now that claims 5 knots off of a six kWh array during sunlight, but this is a smaller (12m) yacht, using current heavier solar panels and less efficient Lead acid batteries. It is also has no sails (which is silly). Why ignore free wind to move and charge batteries? Here is the yacht though.

http://www.dsehybrid.com

My design will increase the size of the solar array by double (minimum) and use lighter panels and will be on a sailing cat. I'm not a yacht designer so I'll soon be hiring professionals to help bring my concept to reality. But, I do have the money, the time and the desire to create my dream. I'm confident that a hybrid system on a blue water sailing catamaran cruiser can use the new emerging breakthroughs in solar panels and batteries to make for a mean, green sailing machine.

Comments?

[brian eiland]

First off I might ask why you didn't continue with your previous discussion of this same subject matter??
http://www.boatdesign.net/forums/multihulls/22m-
cruising-cat-design-concept-23644.html (http://www.boatdesign.net/forums/multihulls/22m-cruising-cat-design-concept-23644.html)

There is a hybrid yacht out there right now that claims 5 knots off of a six kWh array during sunlight, but this is a smaller (12m) yacht, using current heavier solar panels and less efficient Lead acid batteries. It is also has no sails (which is silly). Why ignore free wind to move and charge batteries?

I'm confident that a hybrid system on a blue water sailing catamaran cruiser can use the new emerging breakthroughs in solar panels and batteries to make for a mean, green sailing machine.
Look at the trials and exponential complications this fellow is going thru to get a hybrid yacht:
http://www.boatdesign.net/forums/boat-design/diesel-electric-hybrid-charter-superyacht-development-project-27020.html#post269204
Granted this is larger than you are looking for, but take a look at some of the circular problems he runs into trying to get 'free energy'.

Basically it sounds as though you want a solar powered vessel that can also sail. Even with the emerging technologies of solar power, I do not foresee solar panels directly capable of powering a 50 foot yacht for a large number of years, and/or unless they are the size of a football field. Hopeful energy storage technologies (batteries, etc) will move along at an accelerated pace, but that still won't let you get along with an aux diesel source (hybrid), unless you plan to move along at a snails pace.

Keep track of those new battery technologies here (http://www.boatdesign.net/forums/boat-design/batteries-new-battery-technologies-21869.html), or add to the discussions.

I'll post a reply to you smaller size vessel over on the other subject thread where I suggested an alternative

[Becaris]

I did not continue my previous post simply because this is a new subject and is NOT a continuation of previous subject matter. Certainly my personal project stays the same, but the discussion of this thread is supposed to be about NEW breakthroughs in technologies that are not yet commercially available. And how those new technologies could help to improve a hybrid catamaran.

Also, why does it bother you that I start a thread about new solar and battery technology uses on a sailing cat rather than continue a specific discussion of my yacht project? Are you the forum police or something? Did this thread bother your delicate sensibilities? If so, place a cool wet rag on your forehead, lie down and... get over it.

As to your assumption that I want a solar powered vessel that can also sail... that is a false assumption. All I'm looking at here is how lighter and more efficient solar panels and batteries could change or benefit hybrid catamaran sail boat designs.

No one can deny that more solar panels would charge batteries faster, and/or power an electric motor(s). This is already being done in on this yacht:

http://www.dsehybrid.com

But that's not a sailing cat. What I'm attempting to discuss here is the concept of how lighter, cheaper, and more efficient solar panels and batteries could improve and change the design of a hybrid sailing cat.

Now as to your link to the people having problems getting 'free energy', ALL sailing is about getting free energy. In one form it's called wind. There are, however occasions when the primary means of free sailing energy are not available or convenient. Like when moving around in a marina, or pulling in or out of an anchorage, etc. At those times we currently tend to rely on fossil fuel engines. Can we change that with the new technologies coming out?

In addition to this, there is the need to run our engines a couple hours each day to charge up batteries to power water makers, electronics, air conditioners, etc. In the past it did not make sense to put a large array of solar panels on a yacht simple due to the cost and weight. But new breakthroughs are perhaps changing all that. With enough solar power could we generate and store enough power to never run the engines just to charge up the batteries?

There are already cats that use hybrid electric propulsion in place of fossil fuel engines (Lagoon 440 for example). However there are CURRENTLY limitations to this technology (price and weight primarily). The question is simple, if the cost and weight are reduced, why not add a large array of solar panels to improve what solar panels already do currently on a smaller scale? Why not add more batteries if they are lighter and cheaper so that you can store MORE energy off that array to go further without having to turn on an engine(s)? Finally, if the array is maximized to use as much area as possible, and give you as much power as possible, how fast could the yacht motor straight off say a 11 or 12 kWh array? (Even anywhere from 1-5 knots would be useful for moving about in certain areas).

None of this changes that we are primarily a sail boat, but as solar power is on the cusp of becoming cheaper, lighter and more efficient why not look at the uses to enhance a sailing cat?

[XHeeler]

Green efficient is not cost efficient, and get used to slow

Since we are in a period of transition where battery and solar array technology is immature, whatever you design should have the ability to change these systems to upgrade the boat easily. If I was doing it now, I would start with several Prius battery packs and electrical system, and upgrade to Chevy Volt systems when available.

I think it would be desirable,but very complicated, to have the ability to get to your destination by any one of the three propulsion systems, wind, solar, and carbon. But how do you optimize being a solarmotorsailor? (I made a new word). Well, research all the information on motorsailing and see if you can add more solar power than battery weight to the boat.

For instance, you only get good power from solar for 6 hours in the middle of the day, maybe a little more if you can track the panels toward the sun, but that really increases your wind resistance. Make sure your array doesn't become a sail if you get into a storm. Sails will shade the panels to lower the solar production, which is why the solar c(t)rawler doesn't have them.

If I was going to do it now, I would start with the solar trawler and put unstayed masts in each corner with furling sails. and only use the masts where the sails don't cast shade on the solar array. One mast will always be more efficient with the wind than 2 or 4, but not in this case if you would only use 1 or 2 of the 4 masts. At least those heavy batteries will help your righting moment. Remember to wash that array frequently to get the salt buildup off for maximum efficiency.

I would have a smaller and larger diesel genset with dual electric motors and the best variable pitch feathering props, but only run one motor most of the time.

I would have redundant watermakers to reduce water tankage if it was energy efficient, to offset the battery weight.

I would have minimal amenities. It's normal for green people to sweat, but just about every window would open for ventilation.

And be prepared to never sell this boat.

[apex1]

An array of 54 panels that each put out about 200 watts would get you a around an 11 kWh array.

Assuming a catamaran of about 50', with two electric motors for propulsion, I wonder how fast it could motor using power right off an 11kWh array?

Comments?

An array of 54 panels as mentioned, where do you put them on a 50´cat? Each of them has a 1m² surface! The market estimates a increase up to 14% efficiency in the next few years (from 12% today) (Solon AG).
Assuming they are perfectly positioned and only one third of them is in the shadow of the sail, you would need 72 m² of PV panels.
72 times 600 is 43200$ (one watt is about 3$ at present and will not come down during the next 5 or so years)

So, what was your idea?

[brian eiland]

Some solar related references here:

http://www.boatdesign.net/forums/boat-design/batteries-new-battery-technologies-21869-5.html#post194919

http://www.yachtforums.com/forums/77137-post60.html

[Becaris]

Well, a couple things. I would not plan to motor off the array for any serious distances. For 90% of travel I would be sailing. If the sails blanket some (or even a lot) of the panels while I'm sailing, I wouldn't care. When I do lower the sails I would have a large array to help charge the batteries faster while there is sunlight. While sailing I can use the props and motors if I need to charge the batteries. While at anchor I would have a significant array for making hay while the sun shines (charging batteries).

This whole idea is useless with today's technology and prices. From the beginning of this discussion I'm projecting forward to cheaper, lighter, more efficient solar panels and batteries. As for opinions on how much solar will cost per watt in five years, that's debatable and I can show you just as many projections for less as more. I'm not prognosticating WHEN solar will be cheaper, lighter and more efficient, only that there is a lot of 'buzz' on the net from several manufacturers, universities etc. talking about breakthroughs that address all these problems. I'm also basing this on the history of technology starting expensive and getting cheaper quickly. It's always been the trend, I see no reason to believe that will change.

Since this discussion is based on the assumption that some (even one) of these breakthroughs will pan out, then the question is... if you COULD put say 54 panels on a cat, and have more battery storage (since they would be lighter) what could we do with that?

You asked where I'd put 54 panels, there are 54 panels (to correct scale) on the concept cat pictures included in the first post. This is just a concept, but they are represented on that cat model.

Now, as to redundant water makers,, yes, I would agree that would make sense. Power on a yacht using this (as of yet unavailable) technology would not be the issue, but weight is always an issue. No matter how light a battery might get, if we can save weight in one area we could add more batteries.

Using one of the new possible breakthroughs listed by link above in my original post, you wouldn't have to be so concerned with angling solar panels anymore. They have increased the angle at which the solar panels are efficient by significant amounts.

This yacht is not as much science fiction as you guys seem to think. There are already hybrid cats. The main difference is simply that I'm projecting more panels (because they are cheaper and lighter) with more battery storage (because they are lighter) once weight and price come down. Other than that, there is no new technology here.

We are in complete agreement that this could not be done today, or likely in two years, after that... who knows? Your guess is as good as anyone else as bringing technological breakthroughs to market is a minefield. I'm just hopeful and looking ahead to what I might do IF it comes about in the next few years..

One final note, I don't give a rat's ass about resell value or how much it costs to build a yacht. This is more of a discussion about what could be built with the new technology that is coming down the pipe. I wouldn't build ANY yacht were money something I was worried about spending. A boat is a big hole in the ground where you throw money... I plan to dig my hole vary large and I don't care about how much I toss in. :)

[peterAustralia]

hi Becaris

If you are building a large catamaran, that implies you have money, I guess that is a good start. Some things, crossing an Ocean with 2.5hp, point is that modest power can do good things if modest speeds are acceptable

http://www.tohatsu.com/news/seiko.html

nigel Irens.
High speeds with low power, efficient hullform means less fuel is used (less energy)
http://www.nigelirens.com/FRAMEpower.htm


of course you can do without an engine if you need to, here is a 38ft Wharram that is currenty somewhere near the Marquesas and has no engine at all

http://www.latitude38.com/lectronic/lectronicday.lasso?date=2007-10-05&dayid=13

So maybe having less power input that is ideal, but having a stronger motor that allows for easier docking and getting in and out of inlets. May I ask what you wish to achieve, to cruise in an environmentally sustainable way? or to demonstrate new technology?

The reason I ask is this. If it is the first, maybe is easiest to build a conventional cat with a 4 stroke outboard, and use it sparingly. With the money left over find a way of using it to help the environment.

Can you buy carbon credits?
Is there a way of using money to protect tropical rainforest from logging and clearing? For the money saved you may be able to do really good things by saving a patch of forest from destruction in the long term, maybe go to a small island and say, if you resist the loggers I will pay you so many hundreds to dollars per year to protect what yo have... just an idea

[XHeeler]

and 50 some current highest density panels would weigh more than a ton, which would raise your center of gravity too much for a sailing vessel. I think you should look at nanosolar.com. They are making roofing materials out of solar particles which are less dense and powerful at present, but are 100 times thinner.
consider that the whole gelcoat above the waterline would be the solar array, rather than the current silicon wafers that are so fragile that they need heavy aluminum boxes and glass panels to protect them.

[Guest625101138]

I have been working on the design of a solar/wind powered vessel. The best preliminary design I have come up with so far is a what I have termed a faux-tri. It is a very slender monohull below the water, a conventional monohull above the water but at the surface it is a trimaran.

It is far superior in overall performance than a catamaran or slender monohull. The catamaran will require around 40% more power on the hull for the same displacement in calm conditions and will have much more windage. I doubt that it could be built to the weight target as well. The slender monohull ends up being higher drag by the time it is made wide enough to gain reasonable initial stability.

The faux-tri is very low power, requiring less than 1kW to do 8kts. With 4kW it would get to about 14kts. Just 400W to do 6kts. These figures might seem ridiculously low but they are possible. This boat in the clip displaces 100kg and is doing 7kts with 150W:
http://www.youtube.com/watch?v=8BiGp94RLX0
This is a stabilised monohull, similar hydrodynamically to the faux-tri, without the cabin.

The current evolution of the design requires lithium batteries to keep weight down, carbon fibre construction to keep weight down and would use both solar and wind turbine for energy recovery. Again the latter keeps weight low by avoiding high strength structural elements to support sail loads. The turbine loads are an order of magnitude lower than sails.

The advantage of the combined power collection and storage means that you can collect surplus power when collection is good and release it when collection is poor. This way the speed is kept constant rather than fluctuating as you normally do in a sailing boat unless you resort to motor sailing. Makes sense when you know power is a cubed function of speed. So the power is stored rather than doing 0.5kt faster on a windy afternoon and will boost batteries for holding speed overnight.

The faux-tri design is discussed in more detail on this thread:
http://www.boatdesign.net/forums/multihulls/boxy-simple-8-m-electric-powercat-26940.html

This design would gain from advantages of scale but I am really after a single person boat for coastal hops. It is designed to be self-righting with this in mind.

Rick W

[yipster]

was reading in profesional boatbuilder that new marine lithium ion battery's (http://www.mastervolt.com/view_product.php?lang=2&section=marine&prggr_id=1019&prg_id=1187&pro_id=6103) may couse a hart attack when inquiring for price

[XHeeler]

Maybe it would be more practical to place most of the solar array on a tow behind dinghy. No shade worries, less design problems for the mothership and current boat owners could get it immediately. Cut it loose in a storm and track it's beacon afterwards.

It's small electric motor could make it a limp home tractor, if the mothership's mast or engines failed, that could finish crossing an ocean.

[JonathanCole]

It would be poor design to have solar panels that are shaded by sails. I do not believe that a single response to your post has been factual. The facts are that a very efficient 50 foot by 25 foot cat hull can be driven by the electricity produced by a 15 Kw array of solar electric panels of about 20% efficiency (without sails). This has already been accomplished in the 50 foot cat that crossed the Atlantic a couple of years back. (Actually that boat had less than 15 Kw.)
http://www.solarnavigator.net/transatlantic_21.htm


You don't need to use expensive batteries. Boats are perfectly capable of handling the weight of lead acid traction batteries. Beware of people claiming expertise that is not founded on experience or engineering.

[XHeeler]

Sailors cross the oceans at or almost at hull speed by sailing and/or motorsailing. The risk of weather prevents this from being a leisurely month sail, similar to a protected water, good weather day sail.

The solar navigator did it at 2/3rds hull speed, and were lucky IMO to not have their array removed by a storm (it needs to be sacrificial if placed up in the air like a patio cover) or the ship to be capsized.

There is definitely a need for better design.

[Guest625101138]

.... I do not believe that a single response to your post has been factual. ......g.

Jon
If you are going to make broad sweeping statements like this you need to offer some detailed back-up on all and every point made by others. Something you could not possibly do. It devalues what useful input you might have.

My link provided above offers over four pages of posts. There are numerous proven facts throughout it. Please take your time to identify all the facts and tell us why they are not factual in your opinion.

Rick W

[masalai]

The bigger one designs the more power is needed grows exponentially - look at my build project, in the link below (about one third in to completion so definitely an ongoing work in progress)... I am aiming at as much self-sufficiency as I can realistically incorporate - some 2 years of research and analysis so far and continuing until final purchase and launch date...

As selections are made and purchased, they are entered into the build story...

[Guest625101138]

was reading in profesional boatbuilder that new marine lithium ion battery's (http://www.mastervolt.com/view_product.php?lang=2&section=marine&prggr_id=1019&prg_id=1187&pro_id=6103) may couse a hart attack when inquiring for price

When you start looking at what is being offered in volume in the way of lithium batteries the price is now getting competitive with lead acid from an energy point of view and way ahead from a power perspective.

Look at this battery:
http://www.hobbycity.com/hobbycity/store/uh_viewItem.asp?idProduct=8582&Product_Name=ZIPPY_Flightmax_5000mAh_6S1P_20C_
It is only 5Ah at 22V but it is rated at 20C so good for 100A. It only weighs 750g. All this for USD90. So still 2 to 3 times the cost of energy of a lead acid but you would need a 100Ah lead acid battery to get 100A from it at any reasonable efficiency. The lithium therefore about a quarter of the cost from a power perspective.

When you take into account the much reduced weight of the lithium the energy capacity cost gets even better.

For more realistic boat size batteries (large format) there is a reasonable comparison chart here:
http://www.everspring.net/txt/product-battery.htm?gclid=CJXYs7zC_JkCFdEtpAodWCSsGA
The thundersky batteries are getting mixed reviews in the EV market but look to be good value and seem to be getting better quality all the time. These are my first choice at this stage. Some pricing here:
http://www.electricmotorsport.com/store/ems_ev_parts_batteries_thunder_sky.php
If I get to build the faux-tri I would initially use 12 to 14 of the 90Ah cells. This would give 4kWh for just 42kg. About half of what I would want eventually but still good for evaluation and are not prohibitively expensive.

The link shows the best large format lithium batteries I have actually had my hands on but their production cannot meet demand:
http://lithiumenergy.jp/en/products/index.html
As far as I know their entire production is dedicated to the Mitsubishi iMIEV.

The chargers for the lithium batteries are special purpose. They are able to examine each cell individually to ensure cell ballance. This leads to better life. The technology is advancing rapidly and will be common place in a few years. Most RC planes and some boats are now using lithium batteries so all the kids (and big kids) playing with this stuff are gaining experience with the batteries. Many power tools are using them. Probably half the vehicle population in China are using lithium batteries so a huge emerging market to underpin development.

Rick W

[ThomD]

According to Kurzwell solar is now a digital technology, will follow Moore's law, and efficiency will increase at an exponential rate. But almost all observers will predict a linear improvement in technology. If true, an all solar cruising boat is innevitable in a relatively short period of time.

A twin carbon rig on a cat is the lattest fad. It seems to offer twice the shade, twice the drag when motoring, and be probably 1.5 times more expensive than a single rig, or thereabouts. Possibly it would allow on to claim more carbon credits for the project.

At some point a sail that is the solar panel may be possible. Solar paint seems also to be on the horizon.

When all this happens anyone with a lot of money and a motorboat mentality will be able to drive off into whatever remains of the less invaded parts of the earth.

[masalai]

I would suggest you do not hold your breath in anticipation - someone here was identifying 1000w/sq meter so at 100% efficiency total power is not huge using PV cells or anything directly converting the suns rays - indirect solar is viable now - using what is known as SAILS:D:D:D

[Becaris]

A few things from various posts above:

XHeeler mentioned that 50 panels would weight 'a ton'. The idea is NOT to use current available technology. I'm basing the idea of using emerging solar technologies a few years from now. Several companies have announced much lighter solar panels.

Yipster mentioned heart attacks from the price of lithium batteries, again, this is CURRENT prices. Technology prices fall like rocks. The new lithium batteries already available are much lighter. They price will come down. When it does, using more batteries becomes a viable option for my 'future' technology cat.

Jonathan mentions that it would be 'poor design' to have sails that could shade the solar array. This is not true since the idea is to create a sailing cat (meaning the primary propulsion are sails). While sailing the entire solar array is not needed. A portion of that array will always get sun if the design is done properly. In my example shots notice that half the array is behind the sails. This allows some serious charging to be going on while sailing (a 5 kWh array). With the hook and sails down, the full array is available, or if the need arises to motor off the array (becalmed, for example) the sails would be done anyway, thus exposing the entire array.

XHeeler mentions that speed is sometimes needed to outrun storms (when possible). I agree, which is why the primary propulsion is sail. Generally when a storm is about, so is wind. But... a larger battery bank would allow some extra speed to be used or added via the electric motors for a reasonable time. Speed from electric motors is not a problem, sufficient power storage is the key as they will burn up power at a prodigious rate when 'pushed'. New lighter battery technology is solving this issue since the weight of more batteries is currently holding us back.

ThomD calls twin masts 'the latest fad'. Regardless of whether it is a 'fad' or not has little importance to me. There are factors that I appreciate with the rig and that is why I'm exploring it. Some of these factors are:

1) Lower center of gravity.
2) Redundancy (one mast will still sail the yacht).
3) Strength (the weakest point to mount a mast on a cat is mid bridge, the strongest, over the hulls).
4) No lines to handle, trip over, etc.(rotating un-stayed masts, self furling booms).
5) Easier running down wind (sails goose winged and rotated past mid point toward the bow)

There are disadvantages as well, but not many and not ones I care about personally.
1) Higher cost (debatable, since shorter masts cost a lot less to make than longer ones. But even if they are a little more, money isn't an issue to me).
2) Blanketing (especially on a reach). I'll go a little slower, or change my angle, or spill one sail into the other.
3) Sluggish going about (no jib to 'pull you through). Totally don't care, this isn't a racer, it's a cruiser. If I need to I can use the motors to bump me around if I'm locking up in irons.

Masalai tells us not to hold our breath and use sails. Of course, which is why this is a sailing cat, not a solar driven cat. There is confusion here, but remember, I'm only talking about replacing diesel engines on a sailing cat with other new options, not making it a motor yacht.

[brian eiland]

I'm taking a look at 'near' future technology as applied to a catamaran cruiser. What I mean by 'near' is technology that has been announced, but is not yet commercially available, and how that technology could be used to improve a hybrid sailing yacht.
You might have a look thru this subject thread, I've forgotten how many new ideas have been presented. It might warrant review.

http://www.boatdesign.net/forums/propulsion/new-propulsion-sytems-ships-9630.html

[masalai]

1) Lower center of gravity.
?but, but, but, the wind force is diminished nearer the surface
2) Redundancy (one mast will still sail the yacht).
?If one mast collapses, for any reason something major has broken - that idea "is not working" to quote 3year old grandson
3) Strength (the weakest point to mount a mast on a cat is mid bridge, the strongest, over the hulls).
?who said that - (a mono designer?) again different engineering problem...
4) No lines to handle, trip over, etc.(rotating un-stayed masts, self furling booms).
?Um - simplicity becomes a very complex engineering issue...
5) Easier running down wind (sails goose winged and rotated past mid point toward the bow)
Not with that of any rig like that or even mine (hitch-hiker) Not wing-on-wing no advantage tack downwind is easier & often faster...
There are disadvantages as well, but not many and not ones I care about personally.
?Think again, make some models, do some serious engineering - the basics are not there yet and the technology has a way to go... Design with what you have available, dreamers never stop dreaming...
1) Higher cost (debatable, since shorter masts cost a lot less to make than longer ones. But even if they are a little more, money isn't an issue to me).
?Short masts are NOT effective or justifiable - have you seen many?
2) Blanketing (especially on a reach). I'll go a little slower, or change my angle, or spill one sail into the other.
?Huh? on one hand "designing for performance" and on the other inelegantly "dumping"?
3) Sluggish going about (no jib to 'pull you through). Totally don't care, this isn't a racer, it's a cruiser. If I need to I can use the motors to bump me around if I'm locking up in irons.
?Huh? self contradicting again

and I am no expert, just applying common sense, simple logic and observation....

[apex1]

............the electricity produced by a 15 Kw array of solar electric panels of about 20% efficiency .......


I do not believe that this response to our posts has been factual.

The facts are that a very efficient PV array is far below 20% at present. And will not come up to that figure in the near future. That means you would have to cover about 100 to 120m² of surface to have a stable 15 kw output, dear Jonathan! And thats all just counting the Wp (Watt peak), a theoretical value only, not to mention the performance ratio of 0,7 to 0,8. And so on.
Think twice before typing.

Regards
Richard
btw
my question where to leave all these panels is still unanswered!

[kerosene]

The thundersky batteries are getting mixed reviews in the EV market but look to be good value and seem to be getting better quality all the time. These are my first choice at this stage. Some pricing here:
http://www.electricmotorsport.com/store/ems_ev_parts_batteries_thunder_sky.php



Yeah - from all I have read the liFePo4 batteries seem the most stable and best performing. I believe the a123 batteries are similar stuff. For DIY guy the charging indeed is an issue as the charger has to be matched to the array.

a side note:
I think (fear?) that this battery contest is going to be one that the emerging markets will be dominating in. Its not like china didn't have hands in mobile revolution but in this race they have footing much higher up the ladder. What will "west" do when the innovation and brand identities come from east too? I guess we will still have the precious task of consuming...

[Guest625101138]

........
a side note:
I think (fear?) that this battery contest is going to be one that the emerging markets will be dominating in. Its not like china didn't have hands in mobile revolution but in this race they have footing much higher up the ladder. What will "west" do when the innovation and brand identities come from east too? I guess we will still have the precious task of consuming...

We have the current honour of being a major commodity supplier to China. Our iron ore volumes are still at capacity although plans to expand are shelved for the time being. Aluminium is in dire straits still with world stocks continuing to rise.

China has the intellectual capacity and endeavour to rapidly outpace the rest of the world. They will become less reliant on offshore technology.

You cannot be expert at something you do not do. China will breed manufacturing experts while other countries lose their manufacturing expertise.

I believe Australia and Chile are the major holders of lithium stocks but this is only a small component of the battery cost at the present time.

Rick W

[Becaris]

masalai

Though I don't agree with all of your points on a biplane rig, this thread is not the place to discuss that subject. The subject matter is future technologies applied to a sailing cat. However, if you want to start another thread to discuss biplane rigs, I'd be happy to chime in further with my opinions in that thread.

[Becaris]

I do not believe that this response to our posts has been factual.

The facts are that a very efficient PV array is far below 20% at present. And will not come up to that figure in the near future. That means you would have to cover about 100 to 120m² of surface to have a stable 15 kw output, dear Jonathan! And thats all just counting the Wp (Watt peak), a theoretical value only, not to mention the performance ratio of 0,7 to 0,8. And so on.
Think twice before typing.

Regards
Richard
btw
my question where to leave all these panels is still unanswered!

First off, this discussion is NOT about current technology, it's about breakthorughs in solar and batteries posted by various companies and universities, some of which will eventually come to market.

However, EVEN with that said, there is already a cat powered with a working a 5 kHw array. That yacht is built and working right now using only current technology. You ask where to put the panels? Just look at the yacht, and you can see where they put them.

http://www.dsehybrid.com/

That yacht is smaller than the proposed 50' sailing cat, which could easily have the space to put on more than twice the array used on the DSE yacht. Your question is therefore answered. However, in this discussion we're talking about future lighter more efficient panels than are on the DSE yacht, therefore making the future yacht solar option even easier to achieve.

The point is that the technology already exists and is in use, we're only discussing a more efficient, lighter version and how it could be used on a sailing cat. The discussion of whether it is possible is moot since it has already been done.

[JohnTT]

Your picture makes the point. While it is possible to build a solar powered boat why use it when better energy sources are available. The DSE is not making use of the wind energy that is obviously available in the picture. You're planning sails - a much bigger improvement than a better solar array.

While solar is great for house loads it just sucks for motive power on an ocean going vessel. New technology is not going to fix the sun going down each evening. The foreseeable improvements in battery technology are not nearly enough to address this problem.

And while there's a lot of great things going on in solar and especially batteries today (much funded by excited politicians with little understanding of the science ) - very smart people have been working on this for years. The actual progress has been slow and is likely to remain slow.

Why don't you plan your vessel with a goal of getting the most from each energy source:

a) Sails - improve sailing characteristics so an engine is hardly ever required. 5 knots in 5 knots of wind would be a great start. And make it so maneuverable that you can enter harbors or even dock under sail. It's been done for hundreds of years. I agree with others that those four masts are heavy - and will be very inefficient sail platforms on most points of sail. Mast failure is not a substantial risk with a conservatively designed rig. And, of course, make the boat light and easily driven.

b) A small diesel running at it's most efficient RPM/torque is damn efficient - and very reliable. Instead of a genset (and losing the 20%+ in the genset to electric motor conversion compared to a transmission/shaft) consider a small propulsion diesel with a power take-off hooked to three or four large alternators each with a switch to the sense wire. Use one when not in neutral. Use them all when just battery charging. One engine instead of two to save weight.

c) Work on improving the efficiency of the propeller and shaft. Maybe have it retract. Have a zero degree shaft angle. Consider a retracting water powered generator too.

d) Have solar panels (but much less than you've planned) and put some of the saved money into a couple of big wind generators. The goal should be that battery charging at anchor or under sail is required only in extremely unusual situations.

The above is a boat that you could build today. It will be practical, safe, and relatively inexpensive. I'm quite confident that the total carbon footprint will be little different from the one you could build with the technology that will be available three years from now.

John

[Becaris]

If I was going to start my boat build today (which I'm not) then some of your suggestions certainly have merit. However, I'm more interested in exploring what is coming in four to five years and what could be done IF the solar panels and batteries are cheaper, lighter and more efficient. If these things were true, no one has yet made any point as to why NOT have a larger solar array? Or, how to better use such an array. Everyone seems to be bent on using current prices, weight and efficiency to tell me why NOT to use solar.

But let's look at some of JohnTT's points, with this in mind:

a) Sails - improve sailing characteristics so an engine is hardly ever required. 5 knots in 5 knots of wind would be a great start. And make it so maneuverable that you can enter harbors or even dock under sail. It's been done for hundreds of years. I agree with others that those four masts are heavy - and will be very inefficient sail platforms on most points of sail. Mast failure is not a substantial risk with a conservatively designed rig. And, of course, make the boat light and easily driven.

I totally agree that the yacht needs the best sailing characteristics possible, since this remains the primary means of propulsion (and can charge my new larger battery bank if the sun isn't cooperating, by using my electric motors to generate power). (I'm only planning two masts, not four, and that is for different reasons that aren't really important to this discussion).

b) A small diesel running at it's most efficient RPM/torque is damn efficient - and very reliable. Instead of a genset (and losing the 20%+ in the genset to electric motor conversion compared to a transmission/shaft) consider a small propulsion diesel with a power take-off hooked to three or four large alternators each with a switch to the sense wire. Use one when not in neutral. Use them all when just battery charging. One engine instead of two to save weight.

If I have a larger more efficient solar array and more battery storage, then I can charge batteries (for free) during the sunlight and use them whenever I wish. I don't need to run off the genset in any normal circumstance, it would only be there for emergencies.

c) Work on improving the efficiency of the propeller and shaft. Maybe have it retract. Have a zero degree shaft angle. Consider a retracting water powered generator too.

More efficiency in any area is always desirable, but doesn't change the use of new solar and batteries.

d) Have solar panels (but much less than you've planned) and put some of the saved money into a couple of big wind generators. The goal should be that battery charging at anchor or under sail is required only in extremely unusual situations.

I plan to have twin wind generators, one at the to of each mast, they are in the pictures already of the prototype. Yet, this is just another way of charging my large new battery bank.


JohnTT's final comment was:
The above is a boat that you could build today. It will be practical, safe, and relatively inexpensive. I'm quite confident that the total carbon footprint will be little different from the one you could build with the technology that will be available three years from now.

This may all be true, but I'm not planning on building today. I plan to build a practical, safe yacht using cutting edge technology in a few years. I'm only in the planning stages now. As for inexpensive, frankly, I don't give a damn. Money is not my issue. This does not mean I want to waste any, but it isn't the primary concern. What IS the primary concern is to build the yacht I want to enjoy, I don't plan to ever sell it, so resell value is also of no concern to me. I want that yacht to use the latest technology, which is why I started this discussion about what people may have heard is coming, and how it might be used in a sailing cat. I'm not interested in current technology discussions, I've gone over that with many people in detail.

So... what have you heard is coming and how could it best be used in a sailing cat some years down the line?

[brian eiland]

...Why don't you plan your vessel with a goal of getting the most from each energy source:...

That idea taken to extremes:
http://www.boatdesign.net/forums/boat-design/diesel-electric-hybrid-charter-superyacht-development-project-27020.html#post270083

[brian eiland]

So... what have you heard is coming and how could it best be used in a sailing cat some years down the line?
Can't remember where i saw it or the details, but it was most recent. It talked of fabric material developments that were able to collect solar energy.

[brian eiland]

Have a look over HERE (http://www.boatdesign.net/forums/boat-design/batteries-new-battery-technologies-21869-11.html#post279467)

..and here:
http://www.wetterwille.nl/html/en/electric-hybrid-sailing.html

[Becaris]

New 315 watt solar panels bring us one step closer to using solar in place of diesel for when you can't sail.

http://www.ecogeek.org/solar-power/294

Sorry, this was an old link, I posted the new one below.

[Becaris]

Actually, I put in the older link, here is the newer one...

http://news.thomasnet.com/fullstory/561008

[kerosene]

that news was from 2006
"new, high efficiency panel that is 22 percent efficient. The company expects to have these new panels commercially available in 2007. "

panels are are still heavy

[masalai]

Production versions seem no more efficient than all the other makes using monocrystalline cells that are in the market now???? - http://www.energymatters.com.au/sunpower-230watts-grid-connect-solar-module-p-931.html in Australia...

[Becaris]

I'm not really here to argue about things, just posting what I read about a new 315 watt panel that is 19.3% efficient and works at better angles to the sun. If you don't think that better efficiency is good, then you don't and I'm not here to change your mind. However, in comparing the next best panels available I was able to place an 11+ kwh array using fewer panels (and less square footage), thereby reducing the overall weight of the array.

However, even though the array is lighter with these new panels, it is still heavy. Right now that 11+ kwh array would weigh about 2280 lbs., which I still consider too heavy. Still, this is a step in the right direction, which is why I posted the link (the second link, I mistakenly posted an older link first).

[masalai]

Becaris,
That is, as far as I can tell, the same solar panel???? and thanks for the link and info... I have found that the hype "pre-release" is often what one would call 'ambitious'... - then, in production, reality is found:D:D:D:D Please keep searching as it is only through diligent searching that one can find a better product for a purpose...

[Becaris]

When it comes down to it, this is all about weight. I have to compare the weight of two diesel engines and the full diesel tanks against the weight of the solar panels, batteries, generator and two electric motors. When the weight of these two systems becomes comparable (through advancements in solar panels and battery storage) then the solar/electric/battery system becomes viable.

I'll let 'cost' be the worry of another day, as I believe all technology drops in price over time. If I was starting my planned yacht build today, I would go with two diesel engines most likely, but I don't believe that this will necessarily be true in a few years. Since I don't plan to start my build for a year or two, and even then it will take several years to complete (giving me some time to make a final decision) there is room for new technology to develop. So many companies are currently competing in the solar panel and battery industries that I have little doubt one of them will cash in and give us what we need.

My dream (and that of some of you as well) is certainly to have a cruising sailing catamaran that does not need to pull up to the pump station... ever. Though still a dream, it is inching closer to a reality. I'd appreciate it if anyone who spots promising looking solar or battery technology posted links here in this thread for everyone to peruse. All new technology in these areas is of interest, even if it isn't quite there yet at the consumer level. Maybe it will be in the next few years.

On another note, I would personally be interested in someone with the knowledge to compare the current weight of the diesel system vs. the solar/electric motor/gen. system, just to see how far we have to go to get to a comparable weight. Assume an 11kwh solar array and a 20 meter catamaran and the propulsion systems that would be necessary to power such a craft.

As for electric motors, what size electric motors do you think we would need to adequately power a 20m sailing cat? To help a little I listed the weight of the 11 kwh array of panels in a post above, assuming the weight of those 315 watt panels I read about (unless you have seen a more efficient lighter panel?). What kind of battery storage (quantity, weight) would be sufficient to power a yacht of this size for, say, three hours at an efficient speed? Yes, a lot of suppositions here, but you have to start somewhere. Best guesses are welcome.

[brian eiland]

World's first totally green superyacht

http://www.sail-world.com/cruising/index.cfm?nid=58292&rid=11

[apex1]

Some mighty statements..............like:

the company signed a deal with China's biggest shipping line, Cosco, to retrofit ships with solar energyed sails the size of the wings of a jumbo jet. The sails are covered with photovoltaic panels that can meet some of the ship's energy needs and harness the wind to reduce fuel costs by up to 40%.

Lets see whats left in a year.

[masalai]

Becaris, 20m is far too big for personal transport/cruising as not too many ports and or rivers/creeks in which to shelter, in a storm. 30ft is an absolute minimum for solo cruising and engineering would allow a 20ft beam there BUT weight is the killer....
If you want to carry lots of stuff stick to a big mono and bricks/concrete for ballast and wood hull for repairability... Sort of like a "clipper-ship" hull and modern rig, such that you alone can manage/handle it...

For a cat, and you and partner - around 40 ft is nice - some countries charge extra to enter if you are above 12m/40ft to enter as that is perceived as having commercial potential... Also marina berths cost more (some charging for 2 berths) and some have a clearance of about 25 ft (Darwin, NT) so when you need to get re-provisioned, or, repaint anti-foul, or, enter shallow waterways, you may have difficulties...

Mine is just under 12m (39.3ft) loa, about 21 ft wide and draw 400mm, so I can sneak in to most places for convenience and safety quite easily ...

I am building with 2 aft double berths (one will probable be storage) and the forward berth area will have the genset, HWS, RO watermaker, fuel and water storage... Home comforts are limited but not really lacking in often used (needed) items...

Read through my thread to see what my research found - build time is about 12 months full time + some help...

[allenk]

Becaris - not sure if this thread is dead or moved onto other topics.
I dont have engineering or boat design background but obviously like to figure things out :)

Another way to approach your question starting smaller -
take a 18ft hobie cat, 8ft beam - take off the mast, put flexible solar panels on entire boat even cantelevered over the sides some.
With current technology and weight if my numbers are right you would come up with equivalent 2hp of thrust for a lightweight motor, again you might be at the limit of the cats max load. This would get you a trolling speed.

How much theoretical % increase will the new technology develop?
Assuming this would give you more speed?
Adding the sail back would give you more speed and use?
If you add batteries to charge during off days, are you then limiting range and usability?
The solar panels would make usable deck space to almost zero?
the cost for the panels and the trolling motor currently around $5k-$10k, could be lower?
The result is a very slow, large jetski :) :) but it would use zero gas.
It seems in the near future, the power to weight ratios and the power to cost ratios are not going to be there.
If you go larger, then you get more power but much more weight and more thrust needed....I think the numbers would be worse.

Nice thought to do a loop of the east coast, great lakes, mississippi with zero fuel cost, but guessing still a ways away :)

[Chase_B]

do like they did with the Cub aircraft,..carbonize it :) you could pick up a 18 foot cat with one hand made out of carbon fiber,..but ,..with boats that travel at slower speeds ,..lighter means more vulnerable to wind,..so more power is needed to over come the wind if your using a motor instead of a sail to power it.
just a thought :)

[Becaris]

It's been a long time since I posted the start of this discussion. In that time I have rethought much of what I want to do, and have a half finished 60' cat I'm working on (that doesn't look too much like those early concepts I posted).

At this point I am still planning on going with an electric motor propulsion system, and am keeping an eye on the African Cats Green motion system they are installing on their new 605 design. That system features two 20 kw motors.

http://news.nauticexpo.com/press/african-cats/green-motion-20-kw-motogen-is-being-tested-20089-197488.html

I'm still planning on putting as many solar panels as possible (based on weight and available space), as well as two wind generators, and two 30 kwh diesel generators to power the electric motors when needed.

Due to battery limitations, I won't be able to motor for long (I'm hoping for 3 hours, but it might be as little as 1.5 hours), before I have to kick in the generators. Still, this would be enough to get me in and out of port without using diesel, and let me sail the rest of the time. In any kind of emergency or when I'm just impatient with no wind, I fire up the generators and burn dinosaurs to power my electric motors.

There are a lot of advantages to this system, (and some disadvantages), but for me I feel that this is the best choice. I like the idea of pulling my pod motors out of the water when sailing, less drag, less corrosion and less chance of snagging onto a fishing pot or line. Not to mention avoiding leaking seals on a sail drive, or a leaking shaft... no hole in the hull at all for the propulsion system.

I'm keeping the hulls fairly streamlined, including using rotating dagger boards (think of a lifting keel like on a Southerly 46'), and kick up rudders (ala Kurt Hughes).

I'm still holding out hope for better batteries, better meaning lighter for more stored energy. This is the only way I can extend my cruising distance on motors without burning diesel, but they won't hold me back since I can always use the generators.

There are a few other interesting designs I'm planning on this build, but I'm still kicking around some alternative rig and sail plans. The boat is at a point where major decisions have to be made on that, but I'll have to consult with some naval architects before I completely make up my mind. Things like carbon fiber unstayed mast... or masts, or a more standard rig.

To quote Willie, "So much time, and so little to do... strike that, reverse it."

(Oh, and my apologies, this discussion of my current build isn't really staying true to this thread on 'near future' hybrids... though mine WILL be a hybrid, and it is coming in the 'near' future... still... sorry.)