Future Hybrid Catamaran Cruiser

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...

 

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/...roduct_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

 

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.

 

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

 

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.

 

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

 

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....

 

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!

 

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...

 

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

 

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.

 

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.

 

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

 

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?

 

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