Jimmy Cornell goes Electric, with a Cat

[RaymondR]

So the tokenists spectrum extends from Jimmy Cornell to European countries importing wood from the US??

[mvweebles]

Originally Posted by MichaelPrichard

I'm excited to see how this improves my life; as someone posted earlier, most of us can only afford to get out on weekends and usually just for the day, and in that mode all-electric drive is near ideal.

This is a good post and I agree, it's a good conversation that should view the challenges as solvable puzzle pieces, not excuses to stop trying. EVs languished for years until battery technology took-off 10-years or so ago. These days it's rare to hear the term "Range Anxiety." I know it's there, but range has extended, rapid charge stations are approachable, and users have adapted.

Technological advances are stair-step improvements, otherwise a modern Tesla would have rolled-off Henry Ford's assembly line and Wilbur & Orville Wright would have taken-off in an F-15 Fighter Jet.

I'm sure some will quickly point out "How the heck would you replenish 42kw of battery capacity?" The use-cases for a combustion engines may never go to zero, but they will diminish and those for alternative energy applications will flourish. Folks like Jimmy Cornell and the owner of this cited post are starting/continuing that journey.

From my perspective, this isn't about environmental benefits (though those may be a nice byproduct). But about asking "is there a better way to do this?" Compared to combustion engines, electric motors require very little maintenance, are quiet, economical, run from the same power source already aboard (though obviously needs enlarging), and produce little heat - why wouldn't you use them if you can? Having a sailboat that sails well enough that it only needs auxiliary propulsion makes as much sense to me today as it did 100 years ago when engines were actually called 'auxiliaries.'

[valhalla360]

Originally Posted by slug

Those kinda guyS like Cornell are commercial, sponsor , driven

He got the junk for free...in exchange he promotes it

This is my bet...as long as sponsors show up with batteries and electric motors that's what he will promote.

[SieveSailor]

With electric you can recharge indefinitely from solar, wind, or regen under sail. Any range limitations compared to a diesel need to take that into consideration. Both the diesel and the battery need to store enough energy to get you through to the next opportunity to "fill up". Modern lithium batteries are more than capable than most people think in this regard, but there are trade-offs depending on the type of battery technology as well as the means of recharge. It's not yet for everyone, but I think it will be before long. Skepticism is healthy, but cynicism is a waste of time and energy.

[Pete7]

Think that is a fair comment. I am in the group of "keep an eye on LFP but not yet". Meanwhile nurse the elderly diesel on for a few more years.

[Brewgyver]

Originally Posted by nwdiver

(snippage)

He can take lessons from the kids on Uma,

https://youtu.be/JHUQiRyVV3Y

I wouldn't. They make a video touting they're "off grid" for 5 years, but there the boat is plugged in to shore power at a Marina, which they apparently do fairly often.

Then, Dan tries to get technical, but can't seem to understand the difference electrical between demand, consumption and storage. If he does understand it, he certainly didn't communicate it.

But personally I unsubscribed when they aired a video on how they made a "holding tank" out of a two foot length of PVC pipe, in an attempt to circumvent laws pertaining to MSDs and overboard discharge. They siad they

did the calculations, and it will hold about two flushes, so legally it counts as a holding tank, even though in reality it's going to exit the head, go up, out this and straight to the ocean.

[Brewgyver]

Originally Posted by harlem24

Especially for cats, that are able to get the speed it should work.
Oceanvolt get's about 1kW per motor at around 8kn.

Well, at least that's what they claim.

[catsketcher]

I was interested in repowering with electric but didn't. I went for outboards.

What interests me are the numbers as they are very different from the fuel burning motors. A typical 43ft cat would usually use about 35hp diesels - roughly about 20Kw. That is vastly different from the power of these motors.

Electric motors are very nice with their torque curves and cats can slip nicely in calms with low power but I wonder how the usage will be different from normal motor usage. For example, on the most recent long trip we did a 150 mile motor across Bass Strait. I actually wanted to motor across it as the wind systems were headwinds or gales at that time of the year. The 25hp outboard (I only ran one) was at half throttle - maybe 8KW. A big prop would improve efficiency but still my lighter and easier to push cat would still need about 5 KW to stay at 7 knots in a calm. 5 knots is pretty slow and the drag curve probably goes way up as you hit 7, so Cornell will not be chugging around long distance at speed.

Friends had an electric drive in their mono. They found it great for marina sailing but after some bad experiences of it cruising, replaced it with another diesel. It was an expensive experiment and they are highly experienced and greenies too.

So I am not at all sure how Cornell will get around with such low power. I am sure the computer says the boat needs little power to get up to 5 knots in a calm. But full power in a squall when you need to motor 3 miles after picking up the anchor is another matter. You can sail of course but it would require a large change in how I see many boats used - more like outboards used to be used in early multis - as add ons.

I love electric. It seems great but whereas an electric car can get reasonable range to a fuel car with sometimes better performance (Tesla) I can't see this with boats. The numbers don't seem to add up.

[Brewgyver]

Originally Posted by mvweebles

(snippage)These days it's rare to hear the term "Range Anxiety." I know it's there, but range has extended, rapid charge stations are approachable, and users have adapted.

My place of work, an suburban office campus, added EV charging stations about 5 years ago. The stations were even free of charge (for tenant business employees only) for the first two years, as a commitment by the property owner to encouraging their use. Many of the Volt drivers have told me that their gas engine has to start for some part of the trip, each way. Of course, this is Greater Los Angeles, and people frequently have 50+ mile one way commutes, or worse 20 mile commutes that take over an hour each way.

From my perspective, this isn't about environmental benefits (though those may be a nice byproduct). But about asking "is there a better way to do this?" Compared to combustion engines, electric motors require very little maintenance, are quiet, economical, run from the same power source already aboard (though obviously needs enlarging), and produce little heat - why wouldn't you use them if you can? Having a sailboat that sails well enough that it only needs auxiliary propulsion makes as much sense to me today as it did 100 years ago when engines were actually called 'auxiliaries.'

Of course that's all very true, and 100 years from now you may have to go to a museum to find a diesel engine. I've had to sail all the way back to my slip a couple of times due to engine issues, and haven't had to call for a tow yet, but when I arrive at the boat for a day sail or a few days in the Channel Islands, if that old Atomic 4 doesn't start, I'll not be leaving the slip.

[Brewgyver]

Originally Posted by myocean

Accidentally I have the specific shaft power need of the extended Outremer 45 at hand - it is just 3 kW total shaft power (2x1.5) for a speed of 5 kts: Very good choice, Mr Cornell!

Growing up I had a 14 foot aluminum boat, didn't way 200 pounds, and the 4 hp (3 kw) outboard could maybe get it going about 6 or 7 knots, wide open. So I'd like to see some actual, real world test data showing exactly how to push a boat displacing over 20,000 pounds at 5 knots with 3 kw total electric power...

[harlem24]

Originally Posted by catsketcher

You can sail of course but it would require a large change in how I see many boats used - more like outboards used to be used in early multis - as add ons.

At leat atm that's the way to go.
Question is how do people us their sailboats?
As motor boats with auxillariy sails or as sailboats with auxillary engines?
If you are on a schedule then most likely the first...

[Pete7]

Originally Posted by Brewgyver

Growing up I had a 14 foot aluminum boat, didn't way 200 pounds, and the 4 hp (3 kw) outboard could maybe get it going about 6 or 7 knots, wide open. So I'd like to see some actual, real world test data showing exactly how to push a boat displacing over 20,000 pounds at 5 knots with 3 kw total electric power...

One of our previous boats was a diesel engined 22ft rib weighing 4000 lbs. On a quiet afternoon I put a Seagull outboard on the stern and drove around the harbour. The Seagull was perhaps 3 - 4 hp and achieved 3.2 knots in calm water, but only because it had a huge great propeller turning slowly compared to the Japanese outboards.

Be interesting to see the results of this science project once used for a year or two.

I ran some numbers over the weekend to see what we would need based on some of Sailing Uma's ideas. Looks like 8Kw brushless motor with 14.4kw of LFP. Driven slowly at 4 knots in reasonable conditions might give a total range of 60 miles if there was no wind to sail.

A small matter of the £16k price tag compared to say £6k for a new diesel engine fitted in the UK, so we are not converting any time soon, but thumbs up for those willing to take a risk and push the boundaries.

Oh and then how to charge 14kw if you ever used it all in one go.

[harlem24]

Since Uma is not on a schedule nor in a hurry to get to somewhere, they don't use the motor only for short burst when going on and off anchor or in an out of a marina.
Most of the time they try to sail.
There is a vid, just after they got the battleborns, when they go around in some canals in Florida. That shows how much power they need.
What is often forgotten when talking about conversion, you don't need the fuel tanks anymore. Think about the costs of getting a new one installed, not cheap either.
Specially when you build a new boat that might free up some space to be used differently.

[Franziska]

Hi,


where did you get that information from?
Sounds very inefficient, as Europe has a lot of its own forests.

Apart from that Germany is strongly set towards renewables:

https://www.cleanenergywire.org/news...ower-expansion


Nuclear is on a fade out, as is coal. Both will be gone in 2040. It's not an instant switch and yes we are still importing some power from France, but that will fade too.

Would be nice if the US would aim for something similar, but that ain't happening under their current government...

U.S. Renewable Energy Factsheet | Center for Sustainable Systems

Anyway, lets not run another climate discussion in this thread.

Originally Posted by RaymondR

Because the trees grow again they are considered "renewables" and consequently CO2 emission free. The hydrocarbons are not renewable and Germany shut down their nuclear plants and now import electricity from France which does still generate nuclear power. A large wood fired power station has just been commissioned in Britain to exploit the same CO2 emission free status.

[Pete7]

Originally Posted by harlem24

What is often forgotten when talking about conversion, you don't need the fuel tanks anymore. Think about the costs of getting a new one installed, not cheap either.
Specially when you build a new boat that might free up some space to be used differently.

At 50' North we run the diesel heating regularly. We need about 1.5kw during the winter with temperatures between 5-10c and 1kw during a wet weekend in the summer.

Diesel for heating is kind of difficult to replace, a lot of bang for the buck in a gallon of diesel. Charcoal or wood whilst great at home wouldn't be my first choice on the boat.

Pete