Oceanvolt Servoprop regen tested by UMA

[NaClyDog]

Originally Posted by tp12

Dismissing a result isn't the same as addressing it. If all you've got to offer is they're lying then whatever dude, I'd rather talk with someone else

I never said they were lying. I also never said I believed them though.


Don't give me marketing BS, give me facts. A little critical thinking goes a long way these days.

[Muaddib1116]

Originally Posted by tp12

They showed the performance loss and the results. You haven't substantively addressed that.

I'm pretty sure I did, in a previous post. I have, more than once, made it clear that I think their results were not a lie. All I have said is that they weren't scientific or comprehensive.

[tp12]

Originally Posted by NaClyDog

I never said they were lying. I also never said I believed them though.


Don't give me marketing BS, give me facts. A little critical thinking goes a long way these days.

You've effectively said nothing substantive other than what they've given you footage of isn't true.

Thanks for your input.

[tp12]

Originally Posted by Muaddib1116

I'm pretty sure I did, in a previous post. I have, more than once, made it clear that I think their results were not a lie. All I have said is that they weren't scientific or comprehensive.

No, that doesn't address the numbers they've achieved. You've just dismissed them in a less direct fashion

[Dsanduril]

The "test" is almost useless, there is no real data, except that they were generating 300-500W. Call that 0.5-1HP after efficiency, etc.

For that boat it probably takes 10-15HP to drive the hull at 5 knots under power (all wild, but based on experience, guess). So the drag from regen is on the order of 5-10% of the thrust required to drive the boat. That thrust comes off the top, where large amounts of thrust are required for little changes in speed, so I'd guess that the change in speed is relatively insignificant. It has to exist, but it is probably reasonable to say that the speed robbed under sail is "not significant". We all get to decide significance for ourselves. Look at the amount of power required to drive the boat (and we can generally get that from engine/prop curves) and it would appear that the amount of regen is not a huge proportion of the amount of energy required to drive the boat.

I'd love to see the real numbers rather than guessing.

[Muaddib1116]

Originally Posted by NaClyDog

If their system was so great, why has it required 2 replacements? Do they have any additional power generation and can they actually supply all their power needs by simply sailing? How long can they actually be "off-grid" without plugging-in or starting the genset?

They've had two systems. One was donated by a viewer who upsized on his catamaran. That saildrive was busted, so they got a replacement (warranty?) from Oceanvolt, which is why they can say they've installed 3 Oceanvolt saildrives. This new system came with a new saildrive with the actuated prop. The motor/controller had to be replaced as well, because there are some hardware/software updates for the new prop/saildrive/regen system. This 2nd system is via a colab with Oceanvolt.



They have a decent amount of solar, that has thusfar been their primary power generation off-grid. Over the last couple years in Norway, they've had to depend on shore power much more than they used to in the Caribbean, where I believe the solar was pretty much sufficient. They have no genset.

Originally Posted by BillKny

I know someone who just repowered a 40 foot boat with a new Beta engine for about $20K all up.

Where was this?

[tp12]

Originally Posted by Dsanduril

The "test" is almost useless, there is no real data, except that they were generating 300-500W. Call that 0.5-1HP after efficiency, etc.

For that boat it probably takes 10-15HP to drive the hull at 5 knots under power (all wild, but based on experience, guess). So the drag from regen is on the order of 5-10% of the thrust required to drive the boat. That thrust comes off the top, where large amounts of thrust are required for little changes in speed, so I'd guess that the change in speed is relatively insignificant. It has to exist, but it is probably reasonable to say that the speed robbed under sail is "not significant". We all get to decide significance for ourselves. Look at the amount of power required to drive the boat (and we can generally get that from engine/prop curves) and it would appear that the amount of regen is not a huge proportion of the amount of energy required to drive the boat.

I'd love to see the real numbers rather than guessing.

Apologies, it's a Roberts 35 is what I should have been saying. Edited to also add that the the motor is a Oceanvolt SD15 with servoprop (servo controled variable prop)

The speed they lost is covered in the video as well as their generation numbers - just use those.

[Muaddib1116]

Originally Posted by tp12

No, that doesn't address the numbers they've achieved. You've just dismissed them in a less direct fashion

No. I have not dismissed them. I have attempted to accurately qualify them for those that have not watched the video. If you think that their results are scientific and/or comprehensive, then you don't know enough to be worth listening to.

[NaClyDog]

Originally Posted by Muaddib1116

They've had two systems. One was donated by a viewer who upsized on his catamaran. That saildrive was busted, so they got a replacement (warranty?) from Oceanvolt, which is why they can say they've installed 3 Oceanvolt saildrives. This new system came with a new saildrive with the actuated prop. The motor/controller had to be replaced as well, because there are some hardware/software updates for the new prop/saildrive/regen system. This 2nd system is via a colab with Oceanvolt.



They have a decent amount of solar, that has thusfar been their primary power generation off-grid. Over the last couple years in Norway, they've had to depend on shore power much more than they used to in the Caribbean, where I believe the solar was pretty much sufficient. They have no genset.


Where was this?

Thank you for clearing that up for me. I appreciate it.

[steffan]

I believe this is Uma's second OV. Their first motor was a DIY job made from a forklift motor. The regen on the first OV was not that great, partly due to the specific OV unit, and partly due to the prop, according to Dan. He said something about it maybe working better at speeds higher than they can achieve >8 kts? The pitch on this prop is controlled by the OV and it does look pretty cool. My assumption is they got this unit free from the factory, so I wouldn't expect them to paint it in any kind of bad light. But no worse than half a dozen other YT's Battle Born batteries.

This might be a dumb question on my part regarding the physics: If your sails are trying to power you past hull speed, and that extra energy they could be providing is lost in the drag that keeps you at hull speed... couldn't you potentially capture some of that energy that would otherwise be lost to drag via regen, effectively paying for it by bringing speed back down to hull speed?

[tp12]

Originally Posted by Muaddib1116

No. I have not dismissed them. I have attempted to accurately qualify them for those that have not watched the video. If you think that their results are scientific and/or comprehensive, then you don't know enough to be worth listening to.

Yes, you have. Your reason doesn't matter, non-scientific or comprehensive, whatever. That's a dismissal and doesn't address the numbers they achieved

Thanks for your input - maybe leave it for someone who wants to talk about those numbers. Thanks.

[Dsanduril]

Originally Posted by tp12

Apologies, it's a Roberts 35 is what I should have been saying. Edited to also add that the the motor is a Oceanvolt SD15 with servoprop (servo controled variable prop)

The speed they lost is covered in the video as well as their generation numbers - just use those.

Because they didn't quantify numbers in any meaningful, scientific, repeatable way. In fact, at one point they turned on the regen and their speed went up. If that was a result of just turning on the regen we're back at perpetual motion.

So, I put some estimates of power required to drive the boat against the only real numbers they gave - the amount of regen received - to get some perspective.

[Muaddib1116]

Originally Posted by tp12

Yes, you have. Your reason doesn't matter, non-scientific or comprehensive, whatever. That's a dismissal and doesn't address the numbers they achieved

Thanks for your input - maybe leave it for someone who wants to talk about those numbers. Thanks.

Originally Posted by Muaddib1116

Dan was obviously not being very scientific, but if I recall, I think he was seeing 300W+ at around 6.5kts SOG. He then turned the system off and went up to 6.6/6.7, and turned the system back on and stayed the same and then went up to 6.8, so the wind was picking up a bit. It would be very hard to be scientific about it outside of a lab. Start watching the video at around 24min for his "testing".

In what way have I dismissed them? I literally discussed them here. The fact that I have made an accurate observation of them does not mean I have dismissed them.

[Muaddib1116]

UMA is a Pearson 36, btw.

[tp12]

Originally Posted by Dsanduril

Because they didn't quantify numbers in any meaningful, scientific, repeatable way. In fact, at one point they turned on the regen and their speed went up. If that was a result of just turning on the regen we're back at perpetual motion.

So, I put some estimates of power required to drive the boat against the only real numbers they gave - the amount of regen received - to get some perspective.

And he addressed the increase - I'm not suggesting we're talking lab results here but I think we have a data point to use.

Your estimates I was trying to help by providing the type of boat and the motor/prop they're using. Hopefully that data is available