Electric Trawler

deckofficer said:

Well folks, I'm new to this forum also, and unlike the OP, I enjoy the social aspect of forums. Check my history on the Cruiser's Forum.

I'm starting out a bit more modest in my plans for electric propulsion. I did my thesis on minimum wetted surface vessels (fast ferries) at CMA. I have assembled the components and have an electric kayak. I know there are already electric kayaks, but I don't know of any that have the range of mine.

First is energy storage, and even though we have had some good advances, we are still a long way from the energy density of fossil fuel. This is where we are now

LiFePO4, not as energy dense as other lithium designs, but a whole lot safer.
This is one of the two 12 volt batteries I've assembled with 3.2 volt 100 a-hr cells. 1/2 the weight of a LA group 24 at twice the capacity.


A series string.


Two, so an outbound battery and a return battery.


The best range I've seen for an electric kayak is 16 nm with the typical 60 lb group 24 deep cycle battery. With 60 lbs of LiFePO4, 80 nm range. With thin film solar panals I'm looking forward to some great kayak camping in the Sea of Cortez.


For a quick charge along with a meal and drinks at marinas, this 50 amp charger only weighs 8 lbs. Got to love switching power supplies that do away with heavy transformers.

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The beauty of electric is its so so quiet and vibration free. very addicting

bfloyd4445 said:

The beauty of electric is its so so quiet and vibration free. very addicting

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Yes! and very relaxing. Water fowl and fish are not bothered when I cruise into their domain. My next cruising boat, be it another sailboat or power trawler will have a diesel-electric hybrid propulsion. I've used this for work and am spoiled at the precise power delivery at rpm that is much lower than what any diesel can idle at, all the way down to 1 rpm. No more clunking in and out of gear in those tight spots. Not to mention all available torque at 1 rpm.

As a sail boater I'm at the mercy of fickle winds like this dad and his girls, as I cruised up in my electric kayak.
MOV02923 - YouTube

also the tremendous torq of electric allows eficient low rpm use

This was my last ship (rig) I served on. (6) 5,000 hp electric thrusters backed up by (7) 4.3 MW Cat gen sets.




Yours truly

Greetings,
Mr do. Quite impressive both in theory and practice. I think what the OP didn't realize was exactly what you wrote: " we are still a long way from the energy density of fossil fuel..." With the mass the OP was trying to move, over what we could only guess, distance, present storage technology is not "there" yet. Thanks for the pictures...

RTF,

The examples others posted to this thread, it is doable but the correct parameters have to be met. The one example that wasn't mentioned is this one,
transatlantic21: The world's first crossing of the Atlantic on a solar boat

They pulled it of with a commercial use catamaran and lead acid batteries. Pretty low tech, but light and efficient hulls.

Greetings,
Mr. do. One thing I never found out, or maybe I missed it, was what range OP wanted. What I understood was he wanted a source for a specific motor or it's civilian equivalent. He stated he, his daughter and a friend had designed a system. What I didn't understand was why he appeared to be trying to re-invent the wheel when you and others quoted several examples of "successful" electric boats. Surely a bit of research would have turned up what they were using.
To put it in it's simplest form you have a vessel weighing W tons you want to move through the water at X speed for Y distance. Therefore you need Z power and a way to renew that power either by the mains or solar. I can't do the arithmetic but it would seem fairly straightforward to me.

I think the OP was flying by the seat of his pants. One boat that was mentioned was the Island Pilot DSe (diesel solar electric) that almost fills the bill other than aesthetics. The idea was to max surface area of deck and pilot house with 6 KW worth of un-shaded solar panels. Their first choice of batteries were Odyssey 2150 AGMs, too heavy, not enough storage or energy density and should not be cycled below 50% DOD. Later they changed out to LiFePO4, much better by a factor of 4 on energy density and can cycle 2000 times down to 80% DOD. They didn't size the bank for what those solar panels could offer. If they had, then with 5.5 hours of sunshine per day, it would have been able to cruise at the stately speed of 3.9 kt for 24 hours. Covering 90 nm per day on just solar is pretty good in my book. This first and only boat they built is now for sale, and chances are someone that doesn't understand the systems and limitations will buy it, bad mouth it, and set back electric propulsion. This happened with a French cat sailboat that had hybrid propulsion and was used in the charter service. I'm still hearing all the negatives on that, and another black eye for electric propulsion.

Yes, You Can!

The key to a pure electric powered boat is modest expectations. Having owned Sunshine (our prototype DSe 12m) since we launched her in 2008, I feel I can speak with experience.

At the time of building Lithium batteries were not developed to the point where we felt they were worth the price. Our initial 400 AH/48 v Odyssey battery lasted just about 5 years. When due to be replaced, we DID use Lithium, upping the capacity by 250% (to 1,000 ah) and using the same space and weight. Now we have the electric "gas tank" that we need.

We also used 6kW of solar panels (forget making your own, you can now buy them for less than $1/watt) - from Sun Power (who still makes the highest efficiency cells commercially available) at about $4.50/watt. I would love to have more but felt that cantilevering cells out over the water was not commercially viable.

What we felt was the best hybrid solution shipping at the time (late 2007) was the Steyr parallel hybrid. Today there are multiple solutions available for parallel and serial hybrid and as you are desiring, non-hybrid, pure electric.

Now for your expectations:

1. Modest. By modest, I mean limited speeds for limited distances with enough power left over to get you through to the next charging cycle. We feel that we can sustain about 3.5 knots indefinitely with 6kW of solar array. This was the average speed of a similar catamaran that crossed the Atlantic using Sun Power cells several years ago.

2. Modest. While on the hook, budget your energy use - turn off the lights when you're not in the cabin (most mothers taught us this growing up). Use air conditioning rationally. Equip the boat with energy saving equipment - LED lighting - induction cooking - high tech refrigeration.

3. Modest. Keep weight down as much as possible. You won't have a heavy iron diesel, but you will have a heavy Lithium battery. This is one of the big mistakes we made with the DSe - we wanted her to compete in the luxury trawler market - so we made her interior as finely finished as any made in Asia. Unfortunately, that interior is heavy.

4. Long and Lean - we are working on a trailerable, shippable, electric (hybrid optional) cruiser to compete with the 30 footers. To do this, we'll make her 12 meters long with a center hull of 7' wide - sponsons will extend port and starboard for balance and walk-arounds. The center hull has a water-line beam of 36". The longer and leaner the hull(s), the less resistance up to hull speed. Look at the hulls of rowing shells.

5. Simple interior - maybe use canvas products for stowage and surface coverings. Light counter tops (no granite).

6. Add small wind - a wind turbine rated at 1 kW - 1.5 kW will actually produce around 350 watts on average, day and night, day after day.

7. If you're not a purest (but I feel you might be?), add a 48v DC generator - the smallest one from Fischer Panda will do.

8. Add a 3kW or bigger shore charger. Run all your current from shore to the charger then from the battery to DC/DC converters for 12v loads and intertrer(s) for 120v/240v loads.

9. Our feeling is having an expectation of about 25 NM/day at up to 5 knots (calm). If you need to cross the Gulf Stream to Bimini (about 50 NM), you'll have keep your speed at 3.5 knots or less. Expect to stay at anchor no less than a day or two to build up a depleted battery.

In spite of the nay sayers above - it can be done. Yes, you cannot go into a store and buy one off the shelf. But, you may be old to recall, you couldn't buy a computer off the shelf either. Didn't mean computers didn't work, just you couldn't buy one. You could lease one from IBM or build one yourself.

First step is to find a suitable multihull sailboat to buy - I like the Vietnamese ones that have fold out sponsons (tri-hull), though a good cat will work OK, too. A cat will need two motors rather than one and you may have to break the battery in two to fit.

That should be enough for you to consider?

Sunshine is NOT for sale!

Bob,

I hadn't seen your post when I wrote my wordy one above. For just the reason you mention, we are not selling Sunshine. She is a great test-bed for further development, but not to everyone's taste. That said, she works great within the parameters I mention above.

Thin film. I haven't seen any of that lately - didn't know it was still under development. If so, my guess is that is is uber inefficient in watts per sq. ft.?

Solbian (Solbian Energie Alternative - Pannelli Fotovoltaici Flessibili) has exclusive access to Sun Power cells and configures great panels that ARE efficient. Expensive, too!

Reuben,

My devotion to electric powered vehicles and vessels comes from my work in the oil industry. They needed me (or more accurately my USCG Unlimited Tonnage license) for manning their off shore, dynamically positioned drill ships/rigs. For my paycheck I tolerated the politics of Big Oil, but quietly absorbed the technology employed aboard these vessels. My last ship/rig used (7) 4.6 MW gen sets and (6) 5,000 hp electric thrusters on a rig that displaced 32,000 tons. Since you are the only person on the forum with experience in maneuvering an electric powered vessel, this is something you already know, but for others, the precision that you have as the operator over a mode of propulsion that will give all available torque at 1 rpm and transition seamlessly from forward to astern has to be experienced to be believed. No more clunking in and out of gear or having weak kneed torque at those idle speed rpm.

rjtrane said:

Bob,

I hadn't seen your post when I wrote my wordy one above. For just the reason you mention, we are not selling Sunshine. She is a great test-bed for further development, but not to everyone's taste. That said, she works great within the parameters I mention above.

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That is good to hear. When your ready to sell give me a call. I would love to report in the marine media "I enjoyed the Great Loop and didn't use any fuel".

rjtrane said:

Thin film. I haven't seen any of that lately - didn't know it was still under development. If so, my guess is that is is uber inefficient in watts per sq. ft.?

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You are correct, flexible thin film's efficiency is quite there yet.

One More Thing

Sorry for the continued posting - a closer read of the entire thread leads to more thoughts.

All the talk about batteries is moot. Good batteries do exist and are now affordable for electric propulsion - these are the ones with the LiFePo chemistry - a bit less power density than colbalt, but a lot safer.

Also, efficient motors AND hull forms exist - as mentioned before, slippery multihulls will do the job.

And, speed matters! The only way to get any sort of range (w/o replenishment) is to go SLOW! Our heavy, overweight, and ugly (as mentioned by posters above) Sunshine can average 3.5 knots using 30 amps per motor at 48 volts - this is 3kW total. With NO sun, we can run over 13 hours or 45 NM on a single charge. (If the weight were on target, the hulls would be a lot more slippery and range would be quite a bit better.) 5 knots uses 90 Amps/motor or 180 Amps/8.5 kW - running time is over 4 hours - over 20 NM. Not sure why everyone here insists that electric-powered boats only go a mile or two?

The REAL issue is re=charging the battery. Solar (PV) technology does not
progress at great speed - price has dropped - but efficiency has not reached much beyond 20% (with affordable cells). The reason is I'm guessing, is there is not much demand for more efficient PV arrarys - most homes have enough roof to power the household needs - PV farms can be erected in unused acreage. But, boats don't have the space. Thus, when we did the DSe 12m, we used every available spot for solar.

We ignored small wind (other than in concept drawings). Vertical axis turbines would have been nice, but too heavy and too inefficient. A 1.5 kW turbine typically has an impeller 9' in diameter and should be as high as possible - two would be better. The beauty of wind is that it can be charging day and night. However, if you have looked at any wind speed/output of turbines, you'll see they are all rated at about 25 fps (feet per second) - average wind on the east coast is half that. Output at half the wind speed is about 1/4 the rating - so with a 1.5 kW turbine, you can count on about 400 watts/hour.

It all comes down to expectations - if you're happy going slowly and have no schedule (most retired folks can qualify), and don't mind sitting at anchor for a few days to replenish your energy supply, a well-executed e-boat could work for you. Not for the masses. Not for the weak-knee'd. Not for those who don't appreciate form follows function. But for the person, perhaps an ex-sailor who no longer has crew or the will to work the sails but who appreciates motive-power from nature, an e-boat is a possibility.

Here's a photo of our 1,000 AH battery from Balqon.

Thanks for sharing the picture, it is the first I've seen of the 1000 a-hr cells in a marine application. My history is what your designs have catered to, I started sailing as a boy on the family's sailboat, as a young man bought an old ex-racer Cal 40 and refit for cruising. Cruised solo until I decided to make life at sea a profession and manged to get into CMA in my mid 40's. Now after thousands of sea miles, want to go back to full time cruising but on my schedule and choice of destinations instead of that of the shipping companies. I'm much more comfortable with electrons than sails, and have never been a fan of $15K suit of sails that need replacing every 5~7 years.

Thank you to both Bob and Reuben for adding some solid experience to this thread.

Tad - it is a pleasure to discover this forum and participate.

There was an article on Yahoo today that said the electric car was dead.

And I think as long as we keep finding more oil the name of the game of moving vehicles will be in doing it w less and less fuel. More efficient gas and diesel engines.

manyboats said:

There was an article on Yahoo today that said the electric car was dead.

And I think as long as we keep finding more oil the name of the game of moving vehicles will be in doing it w less and less fuel. More efficient gas and diesel engines.

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Without turning this political, we need to accept that continued consumption at present rates of fossil fuel will lead to serious climate change and loss of our coastal communities. The track that Reuben, Elon Musk and others are on is saving the planet for future generations. I've been privy to back room discussions of the oil industry and even they acknowledge the by-products of known oil reserves would deplete the ozone, but profit now is the agenda. After leaving this industry, I have concentrated my efforts on stored electrons for energy instead of hydrocarbons. As an end user, we can collect and store our energy needs for future use, thus controlling the cost to us. With fossil fuels we are dependent on refiners and whatever pricing the oil companies want. We get all the energy we need from the sun, just need to develop a means of storage that is as energy dense as fossil fuel.

Reuben,

I'm a bit concerned about how close your LiFePO4 terminals are to the other cells. Unlike LA, that in a dead short the voltage sags a lot, our cells don't sag under heavy load. Here is the results of a split second short of just one cell, which is 1/10 the capacity of your monster 1000 a-hr.The thread of the alligator clip just brushed the terminal bolt.

Bob - I have inserted rubber between the two banks, keeping the terminals separate (not shown in the photo) - also covered the terminals with sheet rubber so a dropped wrench doesn't get welded. Good advice, though!

Have you had the chance to notice almost no voltage sag under heavy loads? These cells are impressive and rated very conservative. LA derives their a-hr rating under an easy 20 hour discharge (0.05 C). Our cell's rating is based on 1.0 C, and to 80% DOD instead of the 100% DOD for the rating of LA. The users on the Cruiser's Forum have discovered that for any given LA a-hr rating that filled their needs, they are able to go to 1/2 the capacity with their LiFePO4 cells.

It is nice having a minimum Peukert effect.

Just passed this in Flagler, FL

Any higher resolution photos? I am intrigued - we have been working on a similar idea with long narrow hull and amas (outriggers).

Reuben,

Send me your email and I'll send you what I have. We talked years ago about your boat. I was one of the ones considering a contract on one.

Small world even out here on the water. No reflection on you, 5 minutes after I pulled away from my anchorage this morning a Canadian in one of your Island Pilots passed me then pulled literally ten feet in from of my bow.

Freeway driver...?

How well does that boat (solar-powered tri-hull) do at night? Seems goofy as well as extremely ugly to me.

markpierce: The key to solar powered cruising is energy storage. Today, that means Lithium Ion battery - a very BIG lithium ion battery. The goal is to capture energy whenever it is present (ie. the sun is shining) whether or not you have immediate need of it. Of course, a cruising boat will always be using energy - refrigeration - lighting - pumps - etc. And, with enough storage of energy, you can cruise all night, if you choose.

Regarding your "ugly" comment. I am a great believer in "Beauty is as beauty does." As fuel costs escalate, more and more people will be admiring the looks of a solar-roofed house or boat - big wind farms and small wind near your home or on your boat.

I always find it interesting how often people are quick to comment on other owners' boats - using loaded language - often insulting - using words one would never use face to face.

Since several solar-only powered boats have crossed the Atlantic (very well-publicized, btw), one has to wonder how the heck they kept going at night. Batteries!!!

DaddyO: Sorry about the rude behavior of an Island Pilot owner - I should include as standard equipment a dog shock collar that the drive has to wear to start the boat? LOL.

To me, this has true beauty, not to mention independence from fossil fuel prices.


Oil embargo? $25 a gallon diesel? Shortages? Who cares, your cruising lifestyle will not be effected.

Reuben, would you care to share some unpublished pictures of Sunshine?

markpierce said:

How well does that boat (solar-powered tri-hull) do at night? Seems goofy as well as extremely ugly to me.

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I went to school in your town, CMA, you might of heard of it. I did my thesis on minimum wetted surface vessels, and what Reuben has assembled is true poetry in motion. Might take awhile to catch on, as the maritime marketplace is one conservative group, but what your seeing is the way of the future that will allow a cruising lifestyle not reliant on any outside energy source, you produce and store your own.

It is your attitude that is shared by many in the market place that have kept naval designers grinding out the same old stuff instead of being able to employ what they learned in school. Any mass produced boat has to be like the others if it is going to sell. Designers like Chris White, SMG, and others (Reuben included) are coming out with great designs that cater to the knowledgeable consumer, and producing in small numbers, boats that far exceed in capabilities all the big number production boats.

"Oil embargo? $25 a gallon diesel? Shortages? Who cares, your cruising lifestyle will not be effected. "

Lots more likely that the newest natural gas to diesel refinery being built will bring diesel under $2.00, plus tax .

Considering ALL the costs of yachting , the difference between $2.00 and $4.00 at 150- 200 hours a year is pretty minor.