Star-Lord, Electric Trawler Conversion

Dave,
“he thinks he can make it work”
What does that mean “work”?

As I see it it dosn’t work if it’s not better than a diesel.

Nomad Willy said:

Dave,
“he thinks he can make it work”
What does that mean “work”?

As I see it it dosn’t work if it’s not better than a diesel.

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It does not matter how you see it, it’s not your boat. And your criteria for success is also meaningless: it ain’t your boat.

Nomad Willy said:

Dave,
“he thinks he can make it work”
What does that mean “work”?

As I see it it dosn’t work if it’s not better than a diesel.

Click to expand...

Eric,
It "works" if we get enjoyment and satisfaction out of a project.

There are plenty of people that don't see the sense of owning and maintaining a trawler style diesel boat. You can drive down the coast much quicker and cheaper. You can fly to the Bahamas or Alaska. Why spend the time and money on an old slow boat?

Because we enjoy it.

Nomad Willy said:

Dave,
“he thinks he can make it work”
What does that mean “work”?

As I see it it dosn’t work if it’s not better than a diesel.

Click to expand...

I understand, but the issue is what “better” means. I would suggest that the “better” boat is one that both meets the needs of the owner and provides maximum enjoyment for that owner. As our needs and desires are different, I would confidently say that my boat is “better” than yours, for me. Your boat is “better” than mine, for you.

So when I say that he thinks he can “make it work”, I mean that as giving him a boat that serves his needs and gives him enjoyment.

Go for it, Star-Lord.

Before re-powering my small power cat last year, I checked around for options with vendors such as Elco. Bottom line was that if one can wait another two years, battery technology will break through in critical dimensions such as capacity, weight and cost.

Looking forward to learning more from this thread.

To all that didn’t like my comment above.

Most changes have difficulty getting launched and becoming everyday reality. A friend of mine (the same guy w the Prius that I mentioned above) said when I mentioned that the Prius wasn’t cost effective said “Eric, sombody’s got to lead the way”. There’s more than an ounce of truth in that but what bothers me about it is a lot of this is just a fad and I despise fads. Of course some fads become the way of life later on and electric vehicles are almost certainly going to be that. So by your lead I’ll lighten up. But I’ll walk alongside the bandwagon rather than whoop and holler and climb aboard.


And most of you know I'm a project guy that has a long string of projects that didn't measure up to the products they were meant to surpass. But I had lots of fun and adventure doing them.

!. My prototype boat Easy Rider. Named before the movie. The idea was to be a soft riding hull that was easily driven at moderate speeds of 15 knots or so. The easily driven part was mostly achieved by very light construction. Powered by a 55hp 3 cyl Johnson usually at 11-12 knots. Was very pitch stable and soft riding but wouldn't carry much weight.

2. A scratch and think dwg showing a blunt nosed version of the boat built.

3. The current version of my highly modified Manson Supreme.

I've spent a quarter mil $ prototyping and patenting marine propulsion ideas, which sadly did not turn into commercial success.

My post above was not the proverbial "wet blanket" kind of statement, just a bit of cold hard truth type of engr analysis.

Just hoping he does not have rose colored glasses on. Been there, done that.

And yes, 90% of this boat stuff absolutely flunks any sort of critical analysis.

But we do it anyway because it is fun.

Didnt we have someone on here in the last 5 years that was attempting to do the same thing??..
HOLLYWOOD


Edit..
There is a racing sailboat here in P.T. that was converted to all electric drive, for racing in the bay it works great.. has maybe a 10/15 mile range, is a double ended lightweight sled.. rarely gets beat racing.
When they want to go anywhere they run a Honda generator on deck and can motor around 4 kts.

Electric cars are not a fad. Many countries have said that they will ban the sale of gas and diesel cars in 20 years.

Large scale solar production is able to produce electricity at or below the cost of oil and coal power plants.

One of the constraints to electric cars and commercial solar plants is battery technology. Once that improves , and it will, Solar power will start gaining more momentum, and electric cars will outnumber gas ones

It will work, just depends on what you call “work.” I passed “Electric Blue” on the ICW last month. It’s a trimaran hull that is all electric. Even has air conditioning in the sleeping cabin. You can read about it on their Patreon site, https//:www.patreon.com/ElectricBlue. They also have a Facebook page.

I think the key item that someone touched on is the statement about running the Mainship so it burns about 1gph. That’s slow. At that speed one is not using alot of energy. This rig would be great for cruising the Chesapeake. Just wait for a fair tide.

Agree for sure that we are on the cusp of new (I mean really new) electric storage tech and a big boost in solar collection efficiency, but I like the ideas expressed by the OP. What better way to spend money, effort and enthusiasm than “in the direction” of a more efficient, practical, enjoyable, affordable dream out of the stuff of dreams (a cruising boat). The use of throw-away electric tech makes it even more intriguing to me. He’ll be doing stuff to and old boat and I’m interested in what could be done with an old boat cuz that’s likely all I’ll ever have. Those little refinements to get another 15 minutes of running time or a 1/2 knot in speed are all possible with such a platform, and perhaps convert-able to a new design.

Meanwhile, I doubt that advancements in things like graphine tech and liquid metal storage will escape the OP’s notice as things evolve. Just as it took guys like Reubin Trane to assemble the latest tech to say “OK, here’s where we are”, I need a some guys who will invest in bringing these old tubs quietly, cleanly and efficiently into the future.

Till then, I’m like Eric, a devoted diesel guy who looks for ways he can squeeze another pint of efficiency out of this old hull. But the OP makes a very important point. The used electric tech is available at a fraction of what it originally sold for. If the day ever comes when I could actually IMPROVE my vessel’s performance through a reasonably economical conversion to electric, I’d do it.

There is no problem building an all electric boat. Electric boats have been around for over 100 years. Range is only limited by the number of batteries that can be fitted and how much money you can spend on batteries. The issue is recharging the batteries. As mentioned above a 4.5 kilowatt array can recharge 100 kilowatts of batteries in about 5 days IF those days are 100% cloud free AND the panels can be tilted toward the sun. In the real world with fixed horizontal panels, a percentage of cloudy or even rainy days and seasons other than summer, the solar recharge time is likely to average more like 10 days or even longer. Charging at a marina will most likely be limited to about 12 kilowatts for a standard 50 amp connection (or 3 kilowatts for a 30 amp connection), so you are looking at a minimum of 9 hours plugged in to a 50 amp connection to recharge and about a day and a half from a 30 amp connection.


Now what about range. From what I can find on line a Gulfstar displaces around 22,000 lbs and has about a 40' waterline length. The simple formulae for boat speed versus power at the prop suggest that such a boat will need about 4.5 kilowatts to go 4 knots, 9 kilowatts to go 5 knots, 15 kilowatts for 6 knots and 23 kilowatts for 7 knots. Given a 100 kilowatt battery bank that can be drawn down by 90%, that give the following approximate ranges: 4 kt - 81 nm, 5 kt - 50 nm, 6 kts - 36 nm and 7 kts - 27 nm. These numbers are for flat water and no wind. A bit of chop, a head wind or a foul current with drop the range significantly. This illustrates one of the big limitations of electric boats - they have to go slow to have acceptable range.


Note that I don't want to discourage you. I just want you to be aware of what to expect.


I have one additional comment. One of the benefits often touted for electric boat propulsion is the availability of lots of torque at low rpms. Unless you are dealing with a purpose built electric boat that can accommodate a LARGE propeller, you simply can't use that torque. That is particularly true for a diesel to electric conversion where the prop size will be quite limited - i.e., the amount of torque you can utilize is also severely limited by the prop(s). Consequently, the availability of lots of torque at low rpms is meaningless for a diesel to electric conversion of a trawler.

Sea Word said:

Are you saying that electric versions of ICE vehicles is a fad? I don’t think so, there will be more and more electrics, less and less ICE, and eventually you will not see any gassers outside the classic car museum.

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I don’t know what ICE is re electric boats.
And tinkering w mechanics is all good if it’s safe.
But I think the day when gasoline cars will only be in museums isa long way off. In the 50’s we all thought we’d be taking trips to the moon in 2000. Some new technology gets a foothold and becomes the norm fast and some drags along w present day tech for years and decades.
Lucky for you you’re not the first pioneer to think of electric boats so there's a lot of information and batteries ect around to work with.
Please keep us posted on your progress.
Cheers and luck SW

PS The electric vehicles and hardware aren’t fads. Most of the hype and excitement is. The SUV is a fad. There’s almost nothing about an SUV that is better than a sedan but people are buying SUV’s like crazy.

I keep hearing about transformational changes in battery technology that are on the horizon, and about great improvements in solar panel efficiencies over the years. I don't think either is true.


Lithium Ion batteries (all variants) gave a bump is power density and storage/retrieval efficiency over NMiH, but it's not a lot. And they have been around for 20-30 years. All that has really changed is that production volumes are up. It's not clear that prices have come down at all. Is there something else on the horizon, or are we just using more of the same thing that has been around for 20 years?


And there has been very little change in solar cell efficiency over the past 30 years. 16% to around 22% efficient. But that's all. MPPT charge control has had much more impact on overall solar efficiency than any improvements in panels. What has changed is pricing, and that has led to much wider deployment.


I think we are all so familiar with computer technology which has been advancing consistent with Moore's Law. Silicon density doubles every 1.5 years, and that leads to faster devices with more "stuff" in them. And it leads to data storage capacity that is growing at the same pace. We tend to assume that all technologies progress at the same rate, but they don't. Solar and batteries are not evolving at that rate, not even close. In fact, almost not at all.

I appreciate all the feedback
4.5kw for 4kts sounds good to me

I’ve been refinishing the bottom all weekend. Need to do some research on blisters

Hopefully will get the other engine out next week

May have already asked this but will boat be stable enough to tow in calm water without the ballast of the engines?

Star-Lord said:

May have already asked this but will boat be stable enough to tow in calm water without the ballast of the engines?

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Yes, it will be fine in fair seas.

If you are going to strip the flybridge off, it could make nice motorsailor. It would take a lot of work but yield a boat with all the range you would ever want and efficient electric motoring in when there is no wind. I don't think that particular hull was ever set up as a motor sailor but the gulfstar made a lot of motorsailors and the construction was probably similar. Your hybrid drive, a centerboard, two enlarged rudders, lead ballast, a couple more tons of lead acid batteries for ballast, ketch rig and you are equiped to see the world.

On second glance a yawl rig would fit better.

Gdavid,
This is a trawler forum.
We convert sailboats to trawlers.
Not trawlers to sailboats.
Just say’in

Hey Star-L:

Great project. I hope to read all about it here as your project moves forward.

We will be back to our home in St. Petersburg (Weedon Island area) in the winter and perhaps we can look you up and see how your Gulfstar electric project is coming along.


We have two 235-watt panels on our upper deck, six Fireflys for house bank, and Victron controller. Two 60-hp gas outboards for propulsion. Also owned a Volt.


You have some imaginative, great cost-saving ideas. And the Tampa Bay area is the perfect place for a solar electric cruiser. There was an electric boat-builder that used to be based in St. Petersburg, too; we knew one of the owners.


Have you studied hull forms and understand that full displacement hulls, in particular those with rounded sterns, are the most efficient hulls (i.e. sailboat hulls)? I imagine you have, but decided to go the trawler route for more roof space for panels.


Our friend and marine electrician, Charlie Johnson, is working locally right now on refitting a large catamaran with a Torqeedo inboards/batteries/genny project. Those Torqeedo drop-in systems are wicked expensive, though. I can see your E-Gulfstar becoming a star in the St. Petersburg electric fleet.


Cheers,
Mrs. Trombley

Miz Trom said:

Hey Star-L:

Great project. I hope to read all about it here as your project moves forward.

We will be back to our home in St. Petersburg (Weedon Island area) in the winter and perhaps we can look you up and see how your Gulfstar electric project is coming along.


We have two 235-watt panels on our upper deck, six Fireflys for house bank, and Victron controller. Two 60-hp gas outboards for propulsion. Also owned a Volt.


You have some imaginative, great cost-saving ideas. And the Tampa Bay area is the perfect place for a solar electric cruiser. There was an electric boat-builder that used to be based in St. Petersburg, too; we knew one of the owners.


Have you studied hull forms and understand that full displacement hulls, in particular those with rounded sterns, are the most efficient hulls (i.e. sailboat hulls)? I imagine you have, but decided to go the trawler route for more roof space for panels.


Our friend and marine electrician, Charlie Johnson, is working locally right now on refitting a large catamaran with a Torqeedo inboards/batteries/genny project. Those Torqeedo drop-in systems are wicked expensive, though. I can see your E-Gulfstar becoming a star in the St. Petersburg electric fleet.


Cheers,
Mrs. Trombley

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Isn't the Gulfstar based on a sailboat hull?
I thought they made sailboats and crossed over to power with same or similar hulls?
Or am I dreaming and memory failing?
MizT... how is the cruise N going?

Nomad Willy said:

Gdavid,
This is a trawler forum.
We convert sailboats to trawlers.
Not trawlers to sailboats.
Just say’in

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True, and my deepest apologies, in my defense (in your eyes), at least the flybridge would come off.

There is an entire Industry with a magazine, two trade shows a year, and infrastructure in place to build and support electric commercial vessels. The Magazine is "Electric and Hybrid Marine" and the Shows are in Amsterdam and Ft Lauderdale annually.

The real foothold in this emerging technology is Europe where there are electric tugs and ferries already operating. I understand some of the canal boats have also been converted to electric as their type cruising lends itself nicely to electric.

I have attended the Ft Lauderdale show a couple of years and sat in on some of the seminars and the consensus is that for recreational boats this is coming, and on the brink of being viable, almost. Greenline, Torquedo and of course Elco are already out there. I am familiar with and have collaborated with several hybrid projects and the industry is just waiting for a breakthrough to really expand offerings.

As with almost all things marine, it will be an evolution from the auto industry when it does come, just as the OP is cannibalizing cars for his drive and battery components.

The first all electric commercial ferry to operate in the US is now operational in Alabama. With a very large infusion of support from EPA and DOT and some very shrewd and inspirational development using the original Gee's Bend Ferry as historical framework to support the project.

Because of the nature of the route and schedule this is a viable concept in this narrow spectrum. Without the funding by the outside it would not have happened because of the startup costs.

Trade story about the Ferry

https://www.marinelog.com/news/alabama-ferry-conversion-creates-an-all-electric-first/

Show starts in a few weeks, get your tickets now:

https://www.electricandhybridmarineworldexpo.com/en/

Long term, I think the issue with solar-electric boats will be the limitations of the solar panels. Batteries have come a long way, but as was pointed out earlier, solar panels tend to peak out at about 22% efficiency. Unless there is a huge breakthrough in solar panels, I think the limit of solar panels will likely be about 30% if they are lucky. A 50% increase in efficiency would be huge for boats, but I doubt it is enough to provide practical propulsion for the general slowboat public.

My uneducated gut feel is that PV efficiency and battery storage capacity are not going to make huge improvements from here out. Incremental improvements, yes. Just this nagging bit in physics that puts a wall up at certain numbers.

I might be wrong, but doubt it.

But the electrical tech is going to find apps where it fits well and the market will adapt in cool ways. It is coming for cars, certainly, and in some limited instances, boats.

In cars, the math works. In boats, not so much.

Gdavid said:

True, and my deepest apologies, in my defense (in your eyes), at least the flybridge would come off.

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Gdavid,
My deepest apologies now as I meant that as a joke trying to lighten up.
Going down (or up) new paths is always exciting.

Re the sailboat hull I always thought the Gulfstar was a trawler. And it looks like her stern was extended. But I suppose they could have been a sailboat once.

My first trawler idea was to convert a sailboat to a trawler. I soon discovered almost all sailboats were slack in the ends and trawlers were mostly quite to very full at the ends (bow and stern). So that left my choices extremely limited. So I bought an Albin 25. The Albin 27 foot sailboat is the only sailboat I can remember that was/is full at the ends. Sailboats apparently get their pitch stability largely from the mast.

My sailboat interests were limited to a stint in Mission Bay in SanDiego in the early 60’s. And I was a modifier/experimenter even then as I converted the typical CB sloop to a fixed keel Cutter. I got lucky on the keel/sail balance ... had a neutral helm (tiller).

Greetings,
Mr. Ski. I share your "gut feel" regarding battery (storage) technology hence my question about the consideration of a fuel cell (post #22).

There is a guy here in the Vancouver area who did a conversion on a Tollycraft who has posted a series of videos about the experience. I think it shows both the good and bad. Interesting viewing if someone is looking at a do it yourself conversion.

https://www.youtube.com/user/WhoIsHayley

Nomad Willy said:

Gdavid,
My deepest apologies now as I meant that as a joke trying to lighten up.
Going down (or up) new paths is always exciting.

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I assumed it was light-hearted and prefer to assume everyone is as congenial as if you were chatting on the dock in person where most everyone is thoroughly enjoying discussing boats ad nauseum.
I've never paid much attention to gulfstars out of the water, based on a quick review of nominal lengths of listings for sale, it doesn't appear that the same exact hulls were not shared between the trawlers and motorsailors. Then again the nominal lengths are frequently mean nothing specific. It would make sense that the sailing versions were stretched at the stern to reduce draft but they tend to run shorter than the average trawler so they may be completely different hulls.
If fiberglass resin and my time were cheaper and more abundant, my curiosity in hull design could keep me endlessly entertained.

HaHa me too Gdavid.
But I’m inclined toward plywood.