Electric Sailboat Drives

High Current · Jul 24, 2023

jviss said:
I like the idea of a hybrid. I'm interested to hear your approach to this. I know Vetus made one, I don't think they do any longer.

My boat is such that putting enough battery on it for that is not practical, unfortunately. It would be cool to have a sailboat specifically designed for hybrid propulsion, with a huge, low-down battery bank.

It'll be a retrofit that keeps the original diesel and couples the motor to the prop shaft, although I'm lucky in that my boat has a bit of extra space where I think I can fit everything. As an electrical engineer I'm designing custom controls. I haven't found good off-the-shelf options that aren't offensively expensive, so hopefully I can build something other people might want to buy too...

rgranger · Jul 24, 2023

High Current said:
How many days do you actually drive more than 200 miles?

At least three weekends a month... and the distance is 315 miles (one way). I've wanted an electric truck for years but.... I can't make it work yet. If I could get a truck that had a 400 mile range... I would put a solar panel over the bed cover for charging during the week (I have a short comute to work) with the occasional plug-in... but I would still need that 315 mile range (with some buffer) for the weekends.

stickinthemud57 · Jul 24, 2023

jviss said:
Don't EVER get rid of that! Two strokes are unavailable in the U.S., especially since Evinrude went teats-up, and you can't beat them for horsepower to weight ratio. I have two Merc 15HP 2-strokes that I'm keeping alive - 73lb. vs. about 110 for a 15HP 4-stroke!

Oh, absolutely! A year or so back I was having trouble with it and out of curiosity started researching 4-strokes. The cost itself was bad enough, but to keep the weigh down to a manageable 55 lbs I would have had to go to a 6 hp. Thank goodness I can still get parts for it, but it will be a sad day if I ever have to let it go.

danstanford · Jul 25, 2023

We don't have moorings where I am and so I am in a slip where I plug my electric back in after a sail and she is fully charged when I come back. Motoring out of the harbor and back in never uses more than a few percent.
For the person up thread who had a problem with a gas generator, I don't see the issue. I own a generator for those long trips where I might need to motor for a while without any embarrassment since I only use it occasionally and you use your gas/diesel every time you go out. I am convinced that hybrid is going to be the future though it may be with fuel cells as the source.

Jim Legere · Jul 25, 2023

Its all about usage case. The plugged-in weeknight racer who needs to get off the slip and out to the start line a couple of times a week is the perfect candidate for electric propulsion. The weekend cruiser with 400 W of solar aboard, swinging on a mooring, is probably going to be fine too. The coastal cruiser or the voyaging sailor who need to get somewhere on a timeline, to out run weather, or to make it safely to harbor in a calm, will (probably) always want a diesel. Diesel is 90 times more energy dense than the best state-of-the-art lithium battery systems. You just can't carry enough batteries and solar when you're cruising.

rgranger · Jul 25, 2023

danstanford said:
though it may be with fuel cells as the source.

I worry a lot about fuel cell technology. The hydrogen used in fuel cells comes from electrolytically splitting water. The earths atmosphere doesn’t have any natural hydrogen in it because it is too late for us gravity to hang onto. If the world starts splitting a lot of water and we spill a little bit of hydrogen every now and again… it might not take that long for there to be no water left on the planet.

smokey73 · Jul 25, 2023

Just out of curosity.
@jviss how does the fellow who charges his electric boat at the fuel dock when they are closed and then leaves before they are open and how do they pay for the electricity used? If he gets it free, do you get an equivalent fuel credit.

As I am not an electric car owner, nor do I plan to be since my "use case" doesn't fit the current state of technology. From those who own an electric car, how do you pay for the quick (or slow charging for that matter) at your stop to "refuel" on a trip over your current comfortable range? How long does a "fast charger" take to restore a car battery to full charge, or at least enough charge to complete a, say 600 mile trip? What is your experience on "actual range vs advertised range"? How long to complete that 600 mile trip, including fast charges?

Not knocking it, just curious.

WayneH · Jul 25, 2023

jviss said:
Very nice post, thanks.

Wow, that's a ton of solar on a boat that size! How many square feet, do you think?

BougeRV 200 Watt Solar Panel are 58"x26" or basically the same size as my current 2011 95 watt panels on Impetuous. I found them on Amazon after hearing about the Bouge company on a sailing youtube channel.

Amazon.com

www.amazon.com

Hold out for a sale price on them. I saw $169.99 a month ago.

These are the 95 watt panels separated by the backstay.

sailme88 · Jul 25, 2023

There is now a push on to establish a taxing system for EV cars.. Road tax on fuel isn't being paid yet the wear and tear on the roads continues to grow.. Then comes the sailboats with aux engines. Whether gas or diesel, they pay no road tax.. To prevent improper use, the fuel is dyed. BUT, the fuel sold at marinas is so heavily marked up that no one in their right mind would buy tax exempt fuel for road vehicles...IF it is decided to reinstate the road tax on marina fuels, it would only follow that EB (electric boats) would also get sucked in..

AND THE RIDE CONTIUES.......

LloydB · Jul 25, 2023

I have convinced myself that I have a hybrid boat. I carry a very small electric trolling motor that I seldom use but is available if the outboard ran out of gas. I also carry a Dacron solar panel that I can raise on a tall pole during the day to catch wind and latent solar energy at night when there is any. There is a paddle which doesn't work very well as it runs on Wheaties and is becoming outdated.

kappykaplan · Jul 25, 2023

LloydB said:
There is a paddle which doesn't work very well as it runs on Wheaties and is becoming outdated.

I had some Venturing Scouts aboard one day. Not a lot of wind, so they tried their hand at moving the boat with oars - didn't work.

rgranger · Jul 25, 2023

jviss said:
Is that sarcasm? The exhaust from a fuel cell is warm air and water vapor!

There are other fuels for fuel cells, of course. Even gasoline can be refined for fuel cell use. From the US DoE: "Most fuel cells are powered by hydrogen, which can be fed to the fuel cell system directly or can be generated within the fuel cell system by reforming hydrogen-rich fuels such as methanol, ethanol, and hydrocarbon fuels."

I think you missed my point. We had a debate about this once before. See this thread

DANGEROUS & Misguided efforts in the fight against climate change

Hello Jim and John: I'm not sure if this is the appropriate forum for this post so if you think it should be moved to the "off topic" forum, please do so (and appologies in advance). Last week, I was casually listening to the April 29th broadcast of Science Friday. Part of that show...

forums.sailboatowners.com

rgranger · Jul 25, 2023

jviss said:
You haven't made your point. What is it? Can you just state it here, succinctly?

Okay... let me cut and past it from the original thread..

Last week, (this would have been May 2022) I was casually listening to the April 29th broadcast of Science Friday. Part of that show featured an interview with Joan Ogden who is a professor of Environmental Science and founding Director of the Sustainable Transportation Energy Pathways (STEPS) Program at the Institute of Transportation Studies, University of California, Davis. In that interview, Dr. Ogden promoted the use of hydrogen fuel cells to power cars and commented that the hydrogen used in these cells often comes from natural gas but in the future most of it will come from wind and solar. What Dr. Ogden did not mention is the fact that electricity from wind and solar is used to hydrolyze water to make hydrogen gas.

That is right! The hydrogen gas used to power fuel cells will come from WATER!

Lets do some math using recent data...

A car using a fuel cell to generate electricity will “burn” about 1.6 kilograms of H2 for every 100 miles traveled[1]. In units of water, that is 28.8 liters of water for every 100 miles. In 2019, Americans drove 3.2 trillion miles[2]. If we put that into equivalent units of water used to make hydrogen gas, then we would have had to have hydrolyzed ~92 trillion liters of water in 2019 if we had powered those cars with fuel cells.

Here is an important fact. The Earth’s atmosphere does not have an appreciable amount of hydrogen gas because hydrogen gas is too light for gravity to hold it.

So, what would happen if we accidently spilled 10% of 92 trillion liters of hydrogen gas annually? The Earth could lose ~9.2 trillion liters of water each year. … just from American drivers (For those who don’t think in liters, that is approximately 2.4 trillion gallons). If we globalized fuel cells for all drivers and we also used fuel cells to power homes and industry, we can imagine the Earth losing upwards of a hundred trillion gallons of water each year. To help you wrap your head around 100 trillion gallons, Lake Erie is approximately 130 trillion gallons.

It is my opinion that the promotion of hydrogen fuel cells is a dangerous proposition. Global warming is some thing we can reverse with technology and social changes. Global dehydration is not something we can reverse. If you understand the significance of this analysis, please consider sharing this post.

[1] Fuel Cell.
[2] Average miles driven per year by Americans.

SBO Police Bot · Jul 25, 2023

I was resting (recharging?) so peacefully until a climate change debate started.

Please keep the thread focused on the marine implications of hybrid drive, not any broader climate issues related to such technologies.

High Current · Jul 25, 2023

jviss said:
I like where you are going with this, and I would like to 'subscribe' to your progress, follow it. Maybe even contribute. I'm a EE, too, with experience in a wide range of disciplines.

I have often thought that a pretty good motor/generator could be integrated into the bell housing of a diesel, replacing the gear as well.

Would you follow the early submarine designs, where the diesel could drive the prop, or later, that were totally diesel-electric?

Awesome! Looks like we’re practically neighbors too - I live up by Leominster - so collaboration might be practical. I definitely plan to post my progress once I have something to show.

I think making a retrofit necessitates a “parallel” hybrid for my setup, where the diesel can still drive the prop directly. There are plenty of companies offering pure electric drivetrains already and it seems easy enough to supplement one of those with a generator (series hybrid) if you’re starting from scratch. Oceanvolt, for one, is already doing it.

I’m intrigued by the idea of a dual motor/generator that wholesale replaces the transmission (i.e. traditional diesel-electric). I think cost / size might be prohibitive but it would certainly be elegant and probably easier to install.