Oceanvolt Hybrid Motor

[SDChristian]

So they lied.

[SV DestinyAscen]

Not necessarily. Most cases of perpetual motion machine implications I've heard over the years come from hobbyist and bad mediavetting . More likey caused by mere ignorance and good faith belief.

The most common I still hear every year is some garage engineer figures out you can separate hydrogen and oxygen with electric current, divert hydrogen to modified engine, turns alternator - free energy!

When I'm gone, hobbyists will claim the same with fuel cells.

[valhalla360]

Originally Posted by SDChristian

Debate is useless when one party is convinced that the data are false.

Agreed, there are those who share calculations and physics and are backed up by the fact that these systems have been around for a couple decades and show no traction entering the mainstream but those who believe the data is false keep thinking if they hope hard enough it will come true.

[Cap Erict3]

Sheep and salesmen lie.

[44'cruisingcat]

Originally Posted by SDChristian

Gaining speed without net use of energy does not violate any laws of physics when there is a huge friggin sail collecting lots of energy.

The point is, they are claiming the use of their motors will result in MORE speed than just the sails will produce, yet with no additional energy input.

It's simply physically not possible.

And yes, if people claim this they are either lying or mistaken.

If it were true, then you'd have perpetual motion.

[Stumble]

Originally Posted by 44'cruisingcat

The point is, they are claiming the use of their motors will result in MORE speed than just the sails will produce, yet with no additional energy input.

It's simply physically not possible.

And yes, if people claim this they are either lying or mistaken.

If it were true, then you'd have perpetual motion.

Actually what is claimed about electric motor sailing is possible, and it's possible to increase the average speed without breaking the laws of physics... It's just very very hard to get right, and I see no evidence that's it's been accomplished reliably.

Here's how... (I am making up all the numbers and grossly exaggerating them to make the point. I have no idea what the actual numbers are)

Let's assume a boat that needs 40kw of propulsion to hit 6kn, 50kw at 7, and 80kw at 8kn. But instead of ever sailing at 8kn the boat applies the breaks at 7, and scavengers any excess power to convert to electricity.

On a crossing let's also assume there is enough wind to sail at 6kn 50% of the time, 7kn 25% of the time and 8kn 50% of the time. This gives an average speed of 6.75kn.

If instead of sailing at 8kn that power is stored and the boat only sails at 7kn (while regenerating) and let's assume the passage is 100hours (no matter how far we go). For 25 hours we will be scavenging 30kw=750kwh produced. Which allows us to motor sail at 7kn when there is only enough wind to sail at 6kn (using 50hours*10kw=500kwh). This leaves us with a remainder of 250kwh extra to cover losses, and autopilots...

It's theoretically possible to do this. But I have yet to see any evidence that it has been acomplished. As far as I can tell it would take a CPP which are not available for small boats to work, a good bit of computer power to manage, and a boat with high average speeds. You really need to be sailing at close to hull speed for it to work, since you need to be in the exponential end of the power demand curve.

[Stumble]

Originally Posted by SDChristian

I guess these guys were lying too: "I call it putting the motors in step," says Scott. "If you set it just right, you get Scott. "If you set it just night, you get a zero net use of electricity. And you also get an additional one-half to one knot of boat speed. There's a net speed increase,"

First Electric Lagoon Crosses Atlantic

It's impossible to debate when real world examples are rebutted with "they're lying". Could it be possible that everyone is not lying?

Btw, this is probably your best example, but it isn't very good. After delivering I think 6 boats with the hybrid drives Lagoon had so many problems with them, and such poor overall performance, that they recalled the system and replaced all of them (except for one) with standard diesels. It was such an expensive issue Lagoon then stopped development on electric propulsion.

There are some numbers that really make EP look like it might work, but then you hit the energy density wall. When you compare how much power is available from a pound of diesel and compare it to batteries, the batteries just don't work.

Here's the problem in a nutshell...
48MJ/kg diesel
.5MJ/kg - lifepo4 batteries
.17MJ/kg - FLA batteries

Diesel stores roughly 100 times more power per pound than the best batteries on the market right now, and about 300 times more per pound than standard deep cycle batteries. So just for comparisons sake, my 38' boat holds 40 gallons of diesel which weighs in at around 260lbs when full. To duplicate this with FLA batteries I would need about 78,000lbs. Far beyond the amount possible to store on my boat.

If you want an EP cruising boat, you need better batteries, and they just don't exist right now.

[SDChristian]

Spoke a guy at OceanVolt and he seemed very nice. Highlights; full range is the same or better than straight diesel and the hybrid system is lighter than standard diesel systems (after retrofitting hybrid, they had to add weight to a race boat to stay within the racing class requirements) since they are replacing three diesels (two power and a generator on a cat), with one diesel plus two lighter electric motors. They are also now installing these systems on factory boats (not retrofitting) and he thinks you will see a lot of them hitting the water very soon.

[SDChristian]

Originally Posted by Stumble

Actually what is claimed about electric motor sailing is possible, and it's possible to increase the average speed without breaking the laws of physics... It's just very very hard to get right, and I see no evidence that's it's been accomplished reliably.

Here's how... (I am making up all the numbers and grossly exaggerating them to make the point. I have no idea what the actual numbers are)

Let's assume a boat that needs 40kw of propulsion to hit 6kn, 50kw at 7, and 80kw at 8kn. But instead of ever sailing at 8kn the boat applies the breaks at 7, and scavengers any excess power to convert to electricity.

On a crossing let's also assume there is enough wind to sail at 6kn 50% of the time, 7kn 25% of the time and 8kn 50% of the time. This gives an average speed of 6.75kn.

If instead of sailing at 8kn that power is stored and the boat only sails at 7kn (while regenerating) and let's assume the passage is 100hours (no matter how far we go). For 25 hours we will be scavenging 30kw=750kwh produced. Which allows us to motor sail at 7kn when there is only enough wind to sail at 6kn (using 50hours*10kw=500kwh). This leaves us with a remainder of 250kwh extra to cover losses, and autopilots...

It's theoretically possible to do this. But I have yet to see any evidence that it has been acomplished. As far as I can tell it would take a CPP which are not available for small boats to work, a good bit of computer power to manage, and a boat with high average speeds. You really need to be sailing at close to hull speed for it to work, since you need to be in the exponential end of the power demand curve.

Exactly.

[Stumble]

Originally Posted by SDChristian

Spoke a guy at OceanVolt and he seemed very nice. Highlights; full range is the same or better than straight diesel and the hybrid system is lighter than standard diesel systems (after retrofitting hybrid, they had to add weight to a race boat to stay within the racing class requirements) since they are replacing three diesels (two power and a generator on a cat), with one diesel plus two lighter electric motors. They are also now installing these systems on factory boats (not retrofitting) and he thinks you will see a lot of them hitting the water very soon.

I have yet to see an apples to apples performance installation. They always seem to install smaller EP motors, with less speed, and say it's the same. Then they install a generator that can't even drive these smaller motors at full speed and deplete the batteries in minutes.

Basically they lop off the high end of power availability, and say it's just as good.

It is litterly the same as buying a Prius and saying it's just as good as a Ferrari because they both can accelerate to 50mph.

[exMaggieDrum]

The October 2016 issue (current) of Sail Magazine has an article about hybrid systems: "Hybrid Redux" by Nigel Calder. It is his take on the state of commercially available (or not available) hybrid systems and where they seem to be going. I'm not an expert so just passing this on. I learned some things in it. I suspect it will be controversial to some.

[valhalla360]

Originally Posted by SDChristian

Spoke a guy at OceanVolt and he seemed very nice. Highlights; full range is the same or better than straight diesel and the hybrid system is lighter than standard diesel systems (after retrofitting hybrid, they had to add weight to a race boat to stay within the racing class requirements) since they are replacing three diesels (two power and a generator on a cat), with one diesel plus two lighter electric motors. They are also now installing these systems on factory boats (not retrofitting) and he thinks you will see a lot of them hitting the water very soon.

Still missing the details. range is equal or better...based on what assumptions? A conventional twin 40hp diesel boat running at hull speed vs a hybrid with twin 12hp electric running at 4kts under hull speed.

What is the model and size of the boat? How big did they assume the generator is? How big is the battery bank? What is the efficiency of the single large generator for house loads.

Of course the salesman seems like a nice guy. Salesmen who come across as jerks don't do a lot of sales.

When they share independently tested results, I'll believe it and anyone who comes up a system that is really better will happily get independent testing to confirm it and they will line up all the specs and test results and let better mouse trap sell itself. Every system I've seen dances around the facts.

[44'cruisingcat]

Originally Posted by Stumble

Actually what is claimed about electric motor sailing is possible, and it's possible to increase the average speed without breaking the laws of physics... It's just very very hard to get right, and I see no evidence that's it's been accomplished reliably.

Here's how... (I am making up all the numbers and grossly exaggerating them to make the point. I have no idea what the actual numbers are)

Let's assume a boat that needs 40kw of propulsion to hit 6kn, 50kw at 7, and 80kw at 8kn. But instead of ever sailing at 8kn the boat applies the breaks at 7, and scavengers any excess power to convert to electricity.

On a crossing let's also assume there is enough wind to sail at 6kn 50% of the time, 7kn 25% of the time and 8kn 50% of the time. This gives an average speed of 6.75kn.

If instead of sailing at 8kn that power is stored and the boat only sails at 7kn (while regenerating) and let's assume the passage is 100hours (no matter how far we go). For 25 hours we will be scavenging 30kw=750kwh produced. Which allows us to motor sail at 7kn when there is only enough wind to sail at 6kn (using 50hours*10kw=500kwh). This leaves us with a remainder of 250kwh extra to cover losses, and autopilots...

It's theoretically possible to do this. But I have yet to see any evidence that it has been acomplished. As far as I can tell it would take a CPP which are not available for small boats to work, a good bit of computer power to manage, and a boat with high average speeds. You really need to be sailing at close to hull speed for it to work, since you need to be in the exponential end of the power demand curve.

It's possible if you invent the numbers, in terms of how much energy is recovered at what cost to speed, and how much power is needed to increase speed.

In reality, we don't get to invent the numbers.

Here's the reality. If you're sailing at x knots and you start to generate power using a propeller, the boat slows down. If you divert that generated power into another engine, and IF everything was 100% efficient, no friction, no resistance, no losses, etc etc, the boat will speed back up to x knots. But it will not go faster than x knots. You can't create energy.

But in the real world, there is friction, and there are losses, so the boat speeds up, but it can't speed back up to x knots. It just isn't possible.


BTW catamarans generally don't have a "hull speed".

[44'cruisingcat]

Originally Posted by SDChristian

Spoke a guy at OceanVolt and he seemed very nice. Highlights; full range is the same or better than straight diesel and the hybrid system is lighter than standard diesel systems (after retrofitting hybrid, they had to add weight to a race boat to stay within the racing class requirements) since they are replacing three diesels (two power and a generator on a cat), with one diesel plus two lighter electric motors. They are also now installing these systems on factory boats (not retrofitting) and he thinks you will see a lot of them hitting the water very soon.

A boat in a racing class had a 2 diesels and a diesel generator? Could you ask him which class this was?


He might be a nice guy, but honest?

[exMaggieDrum]

You all should read Nigel Calder's article I noted above. It may salt in wounds or not depending on what you get out of it. Of course, it is just his opinions. He discusses the range issue in particular and mentions OceanVolt in particular. He gives numbers of customers using them and other info.