Jimmy Cornell goes Electric, with a Cat

[BigBeakie]

Originally Posted by fxykty

I’m also very pleased that he is continuing with his project. Given that we’re shortly going to remove propane and have an all-electric galley, I’m very interested to see how he addresses the demand side with more efficient appliances. In our case an induction hob is the easy part, but we’re still unsure about the oven replacement. Currently leaning to a convection microwave. Or maybe we get a diesel oven? It makes me nervous to have an electric oven regularly running for 2 or 3 hours when we bake or roast or keep food warm.

On the generation side, he writes more solar (that’s a no brainer) and a hydro generator (presumably a Watt & Sea). Heck, he should install two W&Ss and forget about engine shaft regeneration. No talk of an ICE generator.

Rather than add a Wait & See with it's significantly lower output, I'm betting he upgrades the OV SD15 to a Servoprop to augment his other Servoprop.
As shown in the latest Uma vid, that gives him about 2kWh hydrogen while sailing along at 8 knots. Then at anchor he needs to boost his solar production and manage his house loads better.

[wingssail]

Originally Posted by BigBeakie

Rather than add a Wait & See with it's significantly lower output, I'm betting he upgrades the OV SD15 to a Servoprop to augment his other Servoprop.
As shown in the latest Uma vid, that gives him about 2kWh hydrogen while sailing along at 8 knots. Then at anchor he needs to boost his solar production and manage his house loads better.

In the first place there are very few boats which are going to consistently sail at 8 knots. Certainly not Uma. Especially draggin a big fixed propeller to turn a big regen unit.

And even if they did it's STILL ONLY ENOUGH POWER (2kwH) TO MAKE 1 OR 2 HORSEPOWER FOR ONE HOUR'S USAGE!

It's stupid! Regen is stupid!

Buy a cat and cover the total surface area with solar and then you can run your galley, but you still can't motor anywhere.

If you go electric, here's the good part: You'll become a better sailor, because you have to.

[Adelie]

Originally Posted by wingssail

In the first place there are very few boats which are going to consistently sail at 8 knots. Certainly not Uma. Especially draggin a big fixed propeller to turn a big regen unit.



And even if they did it's STILL ONLY ENOUGH POWER (2kwH) TO MAKE 1 OR 2 HORSEPOWER FOR ONE HOUR'S USAGE!



It's stupid! Regen is stupid!



Buy a cat and cover the total surface area with solar and then you can run your galley, but you still can't motor anywhere.



If you go electric, here's the good part: You'll become a better sailor, because you have to.

2kWhr generated over what time period?
Or are you saying at 8kt they are generating 2kW so every hour of sailing at 8kt provides 2kWhr of battery juice. Which can be used for 2hr to push their boat at about 3kt for 6nm or used in 1 hr at 4kt to push their boat 4nm or it can push their boat for 4 hr at about 2.5kt totaling about 10nm.

Regen is not stupid, it’s a low return on investment way to generate electricity on a boat when there is wind but not much sun. Wind turbine would probably provide a lot more power per dollar invested.

By the way 2kW is about 2.67hp.

[wingssail]

Originally Posted by Adelie

... are you saying at 8kt they are generating 2kW so every hour of sailing at 8kt provides 2kWhr of battery juice...

Yes

Which can be used for 2hr to push their boat at about 3kt for 6nm

if its true they can go 3kts on 1.33hp

or used in 1 hr at 4kt to push their boat 4nm

if its true they can go 4 knots on 2.67hp

or it can push their boat for 4 hr at about 2.5kt totaling about 10nm.

That one is closer to believable, it doesn't take much power to go 2.5 kts

But you are forgetting the basic flaw: They are not going to sail at 8 knots, EVER, especially dragging a big fixed propeller. And no boat big enough and powerful enough to go eight knotsis going to motor at 4 knots on 2.67hp.

This whole model is based on a bad initial assumption.

For example, my sailboat, which is a very efficient boat, takes about 6hp to fo 4.4 knots and it is really damed rare that I can hit 8 knots, and that's with a folding propeller which gives zero regen.

This whole thing is wishfull thinking.

[harlem24]

Why don't you read the posts correctly or watch the vid?
Their last vid shows a Salona 46 with two OV SD10 with servo props.
In this vid they are sailing at little over 8kn and generating 2kW with both motors on regen.
Since this topic is about the Outrmer that Jimmy Cornell is sailing around the world with also two OV SD, but 15 insteat of the 10 in the vid, his results should be similar.
And sailing an Outremer 45 at 8kn should not be a huge problem, that's what those boats are built for.
And 2kWh for 10h should be more then enough to suit the needs of most crews.

[250224]

Exactly!

I was wondering about Wing's posts this time. The picture here [1, scroll down] shows the outremer doing 14 kts.

And why the negativity against regen? Aren't OV regens and W&S not basically the same, a propeller in the water... --> some kind of charger --> battery? I suppose, Vendee boats wouldn't carry W&S when they wouldn't provide benefits.

[1] https://cornellsailing.com/2020/12/b...ero-journal-7/

[Adelie]

Originally Posted by wingssail

But you are forgetting the basic flaw: They are not going to sail at 8 knots, EVER, especially dragging a big fixed propeller. And no boat big enough and powerful enough to go eight knotsis going to motor at 4 knots on 2.67hp.



This whole model is based on a bad initial assumption.



For example, my sailboat, which is a very efficient boat, takes about 6hp to fo 4.4 knots and it is really damed rare that I can hit 8 knots, and that's with a folding propeller which gives zero regen.



This whole thing is wishfull thinking.

I was tired and sloppy last night.

Agreed, Uma may hit 8kt surfing but it won’t be sustained. Also they have 1 regen motor not 2 so 1kW production not 2kW. Let’s assume they are averaging 500W in winds sufficient to drive them to hull speed. 2 hr of this will provide 1kW stored.

In one of their videos they went 3.1kt using 1.2kW. They gave the values for other speeds but that’s the number I recall.

I want a Cal-34 which is slightly shorter and slightly lighter than Uma’s Pearson 35. From talking to Electric Yacht about the Cal they predicted 2.5kt on 480W, 3kt-960W, 4kt-1930W, ... 6.8kt-10kW.
This was in keeping with Uma’s reported values so I treat them as accurate enough.

Uma has something like 600W of panels mounted which I think is more than enough for house loads. That means anything from regen can be saved for propulsion. On long passages it would be reasonable for them to be fully charged when arriving at their destinations. I believe this is normal for them. When tying up regularly I believe they use shore power to top up between boat moves because there isn’t time for the solar alone to catch up and the regen is producing nothing.

Regen appears to provide a significant amount of energy, albeit a relatively small percentage of their total.

Personally I wouldn’t install regen because there isn’t enough production for the price. Certainly I wouldn’t count on it ever being the majority of production regardless of how much money I spent on it. Since I intend to have a holding prop it will never be an option.

Cornell’s boat doesn’t seem to have had a good grip on their consumption and didn’t have enough solar to make up for that so their plan had insurmountable short term problems. We’ll see if they can rectify the situation. They may not have the installation sorted out properly if the same system provides 2kW at 8kt on a smaller boat.

How did you arrive at 4.4kt using 6hp?
4.4 would be either knotmeter or GPS.
6hp would be either fuel flow meter or propellor curve & tach.

[Hodgdon87]

I sat down with Capt. Conor Dugan who was crew on Jimmy Cornell’s recent Elcano Challenge. He shares the inside scoop about the voyage and discusses the specifics of the OceanVolt setup. It will answer many of your questions and fill in some of the gaps not previously shared online.

https://www.youtube.com/watch?v=6EplXM0fksw&t=13s

[BigBeakie]

Originally Posted by Hodgdon87

I sat down with Capt. Conor Dugan who was crew on Jimmy Cornell’s recent Elcano Challenge. He shares the inside scoop about the voyage and discusses the specifics of the OceanVolt setup. It will answer many of your questions and fill in some of the gaps not previously shared online.

Andrew, thanks for conducting that interview and posting it here. There was some very interesting and valuable information contained in your interview, and I thought it was a very fair summary of the Elcano experience.

As an Oceanvolt customer with an AXC20 system, ( but not yet a user since the boat is not launched yet), I thought it was "interesting" to hear ( from Balance & not Oceanvolt ) for the first time about the Servoprop failing to regen as expected when in rough sea state, or at least when sailing into swell. That explains why Elcano ran the batteries down, which I had been wondering about since reading Jimmy's account.

We spent alot of time analysing EP propulsion requirements for a bluewater cat, and landed on the system we have designed as a result. We took into consideration different cruising grounds with different wind conditions, and planned for adverse conditions in our decision matrix. We had good information on how many diesel engine hours were spent under various conditions, from running at anchor to charge batteries up to adverse conditions extended motoring. That seemed a logical place to start assessing whether EP was viable or not.

We ended up with a more conservative approach than Elcano, with one OV AXC20 in one hull and a Beta 45T in the other. The AXC20 is paired with an Eniquest 16kW DC genset (based on a 29 HP Yanmar), and the boat carries 4.2kW of solar, quite easily on the bimini hardtop. We will be able to electric motor on the output of the solar alone in the calms.

I would suggest the Elcano team put some serious design time into their solar array.

We expect that 80 to 90% of our engine hours use will be on the AXC20, and the Beta will be sitting there as "cheap insurance" for the rare (if ever) adverse events where we need added motoring grunt.

Thanks again.

[valhalla360]

Originally Posted by BigBeakie

We spent alot of time analysing EP propulsion requirements for a bluewater cat, and landed on the system we have designed as a result. We took into consideration different cruising grounds with different wind conditions, and planned for adverse conditions in our decision matrix. We had good information on how many diesel engine hours were spent under various conditions, from running at anchor to charge batteries up to adverse conditions extended motoring. That seemed a logical place to start assessing whether EP was viable or not.

We ended up with a more conservative approach than Elcano, with one OV AXC20 in one hull and a Beta 45T in the other. The AXC20 is paired with an Eniquest 16kW DC genset (based on a 29 HP Yanmar), and the boat carries 4.2kW of solar, quite easily on the bimini hardtop. We will be able to electric motor on the output of the solar alone in the calms.

I would suggest the Elcano team put some serious design time into their solar array.

We expect that 80 to 90% of our engine hours use will be on the AXC20, and the Beta will be sitting there as "cheap insurance" for the rare (if ever) adverse events where we need added motoring grunt.

Thanks again.

That sounds like you've switched to a much more viable system than a pure battery electric.

Use battery electric when you can but when the going gets tough, you can crank up a couple diesels and have around 65hp at your disposal for as long as the diesel holds out. Other than oversizing the genset a bit, I guessing not much cost difference compared to a pair of diesels and a genset dedicated to house loads.

Curious, how big is the battery bank and can it also feed the house loads?

[Hodgdon87]

Originally Posted by BigBeakie

We ended up with a more conservative approach than Elcano, with one OV AXC20 in one hull and a Beta 45T in the other. The AXC20 is paired with an Eniquest 16kW DC genset (based on a 29 HP Yanmar), and the boat carries 4.2kW of solar, quite easily on the bimini hardtop. We will be able to electric motor on the output of the solar alone in the calms.

Sounds like a cool project! I'm assuming this is on a catamaran, what kind of boat?

We've had several customers approach us about installing a similar setup to what you're describing. Many want to combine a OceanVolt servoprop on one side and an Integrel equipped Yanmar on the other. It does seem like it would be a great combination in theory, but the reality was just to complex for us to confidently engineer it. Both OceanVolt and our builder in Cape Town did not want to commit to such a complex system with the potential warranty implications.

Please keep us informed about your current build. I would love to hear feedback about how the system performs once you get it on the water. I'll also be interested to hear how often you actually end up using the Beta for propulsion. Cheers!

[BigBeakie]

Originally Posted by Hodgdon87

Sounds like a cool project! I'm assuming this is on a catamaran, what kind of boat?

We've had several customers approach us about installing a similar setup to what you're describing. Many want to combine a OceanVolt servoprop on one side and an Integrel equipped Yanmar on the other. It does seem like it would be a great combination in theory, but the reality was just to complex for us to confidently engineer it. Both OceanVolt and our builder in Cape Town did not want to commit to such a complex system with the potential warranty implications.

Please keep us informed about your current build. I would love to hear feedback about how the system performs once you get it on the water. I'll also be interested to hear how often you actually end up using the Beta for propulsion. Cheers!

Thanks Andrew. I was probably the first sales prospect for an Oceanvolt Balance 526, several years ago now. I spoke to Phil as my first call, I absolutely loved the 526 and where Balance was headed, but Phil was not interested in my EP ideas, at the time. I knew the AXC shaft drive series was coming out, and still feel that is the best solution for remote cruising on EP.

Re batteries, with the solar we only need 14kW of the 48V Valence lithium, plus run a 400Ah 24V house bank of Victron Smart batts. We have very flexible and redundant charging system.

We ended up working with a local Oz designer & Oceanvolt on a new 50' design, the Freeflow 50. Have had some disappointing issues & delay with getting it built in Thailand, and now Covid has delayed progress on the build, but one day it'll splash....

If we'd been able to go with the 526, we'd have been cruising by now, well and truly.

[jbinbi]

Originally Posted by Adelie

I can think of at least one way to conserve power here. If you have a high mass item like a chicken that’s in the fridge, leave it on the counter for 3-4hr so it comes to ambient temp.
Let’s say it’s a 2.25kg (5lb) chicken and it rises 40F (40F->80F, 22C) that’s about 58Whr or 5Ahr at 12v.

Sorry to go a bit OT here, but food science people shudder at this. Bacteria grow at > 40 F. Chicken at 80 F is not recommended. It might save you some Watts, but potentially you will lose the savings in toilet paper used....[emoji22]

[Yihang]

Originally Posted by Adelie

I was tired and sloppy last night.

Agreed, Uma may hit 8kt surfing but it won’t be sustained. Also they have 1 regen motor not 2 so 1kW production not 2kW. Let’s assume they are averaging 500W in winds sufficient to drive them to hull speed. 2 hr of this will provide 1kW stored.

In one of their videos they went 3.1kt using 1.2kW. They gave the values for other speeds but that’s the number I recall.

I want a Cal-34 which is slightly shorter and slightly lighter than Uma’s Pearson 35. From talking to Electric Yacht about the Cal they predicted 2.5kt on 480W, 3kt-960W, 4kt-1930W, ... 6.8kt-10kW.
This was in keeping with Uma’s reported values so I treat them as accurate enough.

Uma has something like 600W of panels mounted which I think is more than enough for house loads. That means anything from regen can be saved for propulsion. On long passages it would be reasonable for them to be fully charged when arriving at their destinations. I believe this is normal for them. When tying up regularly I believe they use shore power to top up between boat moves because there isn’t time for the solar alone to catch up and the regen is producing nothing.

Regen appears to provide a significant amount of energy, albeit a relatively small percentage of their total.

Personally I wouldn’t install regen because there isn’t enough production for the price. Certainly I wouldn’t count on it ever being the majority of production regardless of how much money I spent on it. Since I intend to have a holding prop it will never be an option.

Cornell’s boat doesn’t seem to have had a good grip on their consumption and didn’t have enough solar to make up for that so their plan had insurmountable short term problems. We’ll see if they can rectify the situation. They may not have the installation sorted out properly if the same system provides 2kW at 8kt on a smaller boat.

How did you arrive at 4.4kt using 6hp?
4.4 would be either knotmeter or GPS.
6hp would be either fuel flow meter or propellor curve & tach.

We are talking about uma’s recent sail on a salona 460 with twin OV. Not their old boat.

That’s what the video is about.

[Yihang]

https://www.youtube.com/watch?v=6Epl...anceCatamarans