Using electric motors instead of Diesel on your cat

[44'cruisingcat]

Originally Posted by BigBeakie

Interesting thread.

Interesting for the reason that that many have offered opinions that basically are along the same old lines that basically EP is not viable for cruising boats, but only for pottering around the marina, or whatever. Or it's too "inefficient", too unreliable etc etc etc.

And it is true that this is leading edge technology when considering some of the concerns ie the reliability, adequate power, the range, the maintainability if something doesn't work, yada yada yada.

But NONE of these concerns are show stoppers, except one, and that is there is no question that a really high quality (ie right power and robust & reliable) EP solution is more expensive right now compared to an equivalent power diesel solution. Somewhere between 50% and 100% more initial cost than diesel system depending on the vendor and how sophisticated the technology used.

And of course, as always, it will take some success stories of appropriate EP cruising boats to change set in concrete opinions, which is understandable.

From what I can see in existing technology and equipment available right now, the best application of EP is a good sailing performance cruising cat. Why? Because at some point you will need to, or rather choose to, motor for extended periods when becalmed. So with a system that has 2 motors and a dedicated propulsion battery for each motor, you can motor off battery with one while you are charging the other battery with the generator, and keep switching back and forth.

You also need a healthy solar array for house loads and propulsion battery charging in most times when you don't need to motor for long periods ie less than 4 o 6 hours depending on battery capacity.

Lithium batteries are a given. EP regeneration is nice to have for keeping up with passagemaking higher electrical loads without running the gennie at night.

Since for most motoring events the solar (and/or regen) will fill up your battery tank instead of prehistoric liquified swamp plants, it's only a matter of time until the Total Cost of Ownership curves of EP vs diesel crossover and EP will be less costly than diesel, considering all cost factors. The slope of the graphs and hence the crossover TCO point depends mainly however on how much motoring you do per year, which depends on your cruising area wrt wind availability etc. We estimate our TCO crossover will be 4 to 5 years for the South Pacific cruising we are planning. In 5 to 10 years, we can see that diesel availability may well be an issue in Pacific Island nations, so that has to be factored in as well. But not relevant in other regions.

But to suggest it isn't viable is not, IMO, an accurate assesment of where things are at right now. Systems are in implementation now that will change opinions once the good news starts filtering through, we just need a bit of patience, as I've said before.

Ok, let the arrows fly now. Let's discuss it Tell us why, based on current state of the art EP, a cruising boat cannot be EP, and indeed, why it cannot be an all electric boat. I'm here to learn

Amps in vs amps out. Unless you have an internal combustion genset, you simply can't put enough amps in to match the amps out.

And once you fit the genset, you're no longer all electric.

Even the "All electric" boat that went RTW needed to use propane for cooking.

[GoingWalkabout]

Originally Posted by Lars_L

Steve & Linda Dashew states in one of their books, that’s on a boat for circumnavigation it’s recommended that you can go for motor 700 M.

I have on my boat 280 W of solar panels. That means that I can get out approximately 30 W around the clock. I guess that a 30 W electrical motor can give my boat a speed of 1 knots or 24 M for a day. That’s certainly MUCH more than not move at all, but it will take its time to move 700 M.

I'm going to shoot for 2,000W combined solar panels on my Cat. Mind you a Cat does gave more space.

Concerning another posters claim that there is incremental performance increases this is not so true now. We have seen some great leaps forward both in battery and solar panels. I'm looking at a 450W solar panel at the moment. Add to this the significant innovations being made too EP motors with what 8 would compare to the old bicycle alternator giving power while I'm motion, in this case whole under sale and you have over the past 12 months a technological convergence that a huge leap.

That's the great thing about technological innovation. Separate component developments when brought together can create a significant jump in performance.

I think in the next 12 to 18 months we are going to see even more significant advances in battery performance at which time the scale of should I shouldn't I will tip very much in favour of a big yes to I shall.

Of course this is only my opinion which is based both on my own logical evaluation of my information at hand and my emotional love of quite and clean motoring when needed.

[2Hulls]

I sincerely hope the solar production and battery storage capabilities improve to the point that a fuel free cruising sailboat can be viable. The Admiral and I do very well with our 700 watts of solar and my boat has used an average of only about 300 hours/year of diesel run time - very little of that for charging batts only. No, it's not a dock queen.

Propulsion could be the easy part of all electric on a good sailing boat. Cooking and water heating and all the rest will likely be most of it given the terrible efficiency of resistance heating. So when evaluating the break even point, keep in mind some hidden efficiencies of diesel propulsion: we have two alts on each engine and a water heater on each engine. When we have to motor (almost always on one engine) we make use of the "free" electricity to make water, heat water (with engine waste heat), run the breadmaker, run the washing machine, load up the frig/freezer, make ice, send emails on the SSB, play the music REAL LOUD, etc., etc., not to mention charging the batts all at the same time. That's a lot of amps and we don't even have A/C.....

2 Hulls Dave

[cwjohm]

Gents

Just a few back of the envelope calculations using electric motors.

Becalmed for two days on a passage - even assuming low cruising speeds like 2Kn motoring - approx. 400KWH over 24 hours

Motoring into 40Kn where sail cannot be used - ~30Kw per hour.

Protection from lee land in rough conditions where motors must be used for safety - ~20KW per hour.

Where pray tell is all of this power coming from? Where does it come from when you are motoring at night? Where does it come from when you need maximum power to keep the boat safe?

All very nice if you motor out for the day, sail around for a day or so, and come back home, but totally impractical for anybody out cruising.

Sure, maybe in 5-10 years, and that is great if you can wait 5-10 years. For most of us that want to be out cruising now, there is no option but diesel motors.

[BigBeakie]

Gents

"Just a few back of the envelope calculations using electric motors."
Back of the envelop EP system design isn't good enough , you actually have to use realistic data to make good choices on the important parmeters like 1. What motor power do you need for a specific boat? 2. What motoring time/range will you need? 3.What battery capacity (and therefore charging capacity) will be needed for the scenarios that will be encountered?

"Becalmed for two days on a passage - even assuming low cruising speeds like 2Kn motoring - approx. 400KWH over 24 hours"
Where are you coming up with these figures? Your 2Kt scenario using 17kWH is way off base, unless they are massively inefficient motors on too big a boat.
Here's a real example on a 44 Oram in Caloundra; he has Torqeedo Cruise 4.0 motors for the last 4 years. He has 500kW solar and a 6.5kW diesel generator. Boat is fully loaded for cruising and on the solar alone he is getting 2.5kts, continuously. Note well, on solar alone, which he calls "motoring from the roof." Using the genset for motoring he is getting 5.5 to 6 kts. He hardly ever uses the gennie, in fact he is still using the original diesel fuel from his first fill up 4 years ago which was 60 litres!! He is wondering about the effective age of diesel fuel. Does that answer where all this huge amount of power is coming from?

Motoring into 40Kn where sail cannot be used - ~30Kw per hour.
Again, an over estimation of what is required. Are you trying to portrat EP in the worst light possible??? Why can't sail be used, BTW?
In my case I will be using 30kW (40 HP) motors, but the system will draw 6kW per hour for extended motoring, using one motor at a time while the other side charges from the 6.5kW gennie. The Kiwiprop will be sized to be optimized for cruising speed (6 to 7 knots) using 6Kw/H. That gives me 3 hours on each motor from the propulsion batteries before charging is required. That's 6 hours of silence, no fumes, no vibration at cruising speed.There is no need to go full speed ahead, especially into 40Kt chop! So at slower speeds I will get alot more range and motoring time on the batteries alone. Add the gennie to motor continuously, until the diesel runs out, same as anybody. Except that under solar alone I will still be making way

Protection from lee land in rough conditions where motors must be used for safety - ~20KW per hour.
Yes agreed, but for how long do you need full speed until you get cleared of lee shore and you can then sail? I'll have about 1.5 hours at full speed. But why would I need full speed? The thrust from the right combination of electric motor and prop is just awesome, and progress against high winds, adverse sea state, tidal currents etc. is really impressive with EP at very modest battery draw.
So I would like to hear from cruisers who have motored at full speed. Why was it necessary, and what was the longest time required?

Where pray tell is all of this power coming from? Where does it come from when you are motoring at night? Where does it come from when you need maximum power to keep the boat safe?
I think I have adressed these questions. It comes from batteries, and it comes from a generator when the motoring requirement goes beyond what can be delivered from the batteries alone, ie the gennie charging the batteries. Pretty simple, really.

All very nice if you motor out for the day, sail around for a day or so, and come back home, but totally impractical for anybody out cruising.
OK, whatever you say. Let's see some analysis that uses real data that demonstrates your point.

Sure, maybe in 5-10 years, and that is great if you can wait 5-10 years. For most of us that want to be out cruising now, there is no option but diesel motors.
Really??? Good EP is available right now, for those who wish to be serious about it, and where the TCO makes sense financially. If you motor quite a bit, it makes perfect sense and is, in fact, a money saver. The numbers aren't hard to run. A cursory look at what is happening in the commercial boating scene shows hard headed business analysis is choosing serial electric hybrid over ICE diesel for the benefits and cost savings.

I'll just comment that there really seems to be alot of FUD surrounding EP. Maybe it's the failures that are disproportionately influencing opinions. Like Lagoon's inadequate attempt, or bad system design by those that just cobble it all together without the necessary safety, robustness and fault tolerant aspects built in. Dunno, but just saying basically it can't work, seems a bit like naive scepticism to me.

[44'cruisingcat]

Originally Posted by BigBeakie

Gents

Here's a real example on a 44 Oram in Caloundra; he has Torqeedo Cruise 4.0 motors for the last 4 years. He has 500kW solar and a 6.5kW diesel generator. Boat is fully loaded for cruising and on the solar alone he is getting 2.5kts, continuously. Note well, on solar alone, which he calls "motoring from the roof." Using the genset for motoring he is getting 5.5 to 6 kts. He hardly ever uses the gennie, in fact he is still using the original diesel fuel from his first fill up 4 years ago which was 60 litres!! He is wondering about the effective age of diesel fuel. Does that answer where all this huge amount of power is coming from?

We recently met Neil at the Gold coast. He was stuck there for a few weeks waiting for one of his motors to be repaired. Again.

The claimed fuel economy is understandable, when you know that for instance, he avoided motoring so much he once took more than 24 hours to get from Mooloolabah to double Island point! No wind, wife (now ex wife) being severely seasick, but he wasn't going to motor.

He was of course, a Torqueedo salesman. Not now though. What's more, he's been told from now on HE will have to cough up for the repairs. The (well used) warranty is over.

Last words we heard from him were that he's going to be looking into outboard motors.


BTW, if anyone really DID manage to fit 500 KILOWATTS of solar to their 44 foot boat, solar/electric would most certainly be viable, no argument here at all. Disappointing if it could only manage 2.5 knots though.

[seandepagnier]

Originally Posted by rwidman

Perhaps in five or ten years, solar collectors and batteries will improve enough and become affordable enough to make an electrical powered cruising boat practical. Not today though.

Solar powered boats have been practical for a long time already.

Having to go to a dock to refuel isn't very practical, therefore diesel engines are not practical.

Originally Posted by David M

Diesel electric systems or diesel-electric motor-battery systems do not save weight over a purely diesel drive system. The propulsive thrust generated per pound of drive system mass is greater for a strictly diesel drive system.

Electric motors can be driven at 3-4x their continuous rating in bursts. A small 5kw electric motor can therefore output 30hp for 30 seconds. The weight of the mars etek 0708 is 30 pounds. What diesel can do 30hp and weighs 30 pounds? In fact, there is no diesel that exists that can do a continuous output of 7hp that weighs close to 30 pounds either.

Also, electric motor output 7hp is equivalent to most 15hp diesel because the system is designed more for efficiency with a larger slower turning propeller. The electric system is much more efficient over a wide range of power output.

Diesel fumes are incredibly bad to breath and cause brain damage. This explains why a lot of people on this forum who use diesels defend using them.

Never buy torqeedo they are a rip off, break often, and you cannot get parts, only a whole new system at a new price.

watts needed to push my boat (full keel 8,000 lbs)
2 knots - 150w
3 knots - 300w
4 knots - 600w

[BigBeakie]

Well 44CC that's interesting because I have an invitation from Neil to go see his boat and EP and he is very enthusiastic about it. So there seems to be a disconnect here between what you have just said and what I have heard about his current situation, so I'll check it out and get back to you on that.

However these are the figures that he is reporting & that he is saying should be written up by a journalist for a sailing mag, so again, I'll check it out and report the results, hopefully before too long.

[BigBeakie]

Boat Alexandra,

"Diesel fumes are incredibly bad to breath and cause brain damage. This explains why a lot of people on this forum who use diesels defend using them.

Never buy torqeedo they are a rip off, break often, and you cannot get parts, only a whole new system at a new price."


You went from the sublime to the ridiculous in one paragraph.

The joke about diesel fumes being bad to breathe (sic) and causing brain damage etc. ...... is very good

But then you follow it up immediately with a ridiculous general statement about Torqeedo being a rip off, break often, and can't get parts. What rubbish! If you're going to slag a vendor on the forum, and put your credibility on the line by impuning the reputation of someone else, it might be good form to have a fair amount of data to support your claim. And your data is what? Oh yes, we remember. You took apart a Torqeedo and stuffed it up, and then whinged that they wouldn't repair it under warranty. I'm sure we are all shocked to hear that! And then they wouldn't sell you a part so you could royally stuff it up even more, or worse, hurt yourself trying. So you have a data point of....one?

Those crazy Europeans must be really stupid to buy so many Torqeedo motors eh? Like, Torqeedo have a huge market share ( about 70% last I heard) of outboards 10HP & under in Europe.

That would be because they are ripping everybody off, the motors break all the time, and getting parts is a huge issue. Sure thing.

Just because you are bitter and twisted about your self inflicted troubles with Torqeedo, does not mean you can try and influence others on an open forum about a product or company. Especially since it was self inflicted.

Have a think about it....it's called ethics.

[44'cruisingcat]

Originally Posted by BigBeakie

Well 44CC that's interesting because I have an invitation from Neil to go see his boat and EP and he is very enthusiastic about it. So there seems to be a disconnect here between what you have just said and what I have heard about his current situation, so I'll check it out and get back to you on that.

However these are the figures that he is reporting & that he is saying should be written up by a journalist for a sailing mag, so again, I'll check it out and report the results, hopefully before too long.

We spoke to him about two weeks ago. Give him a call. I can give you his number if you like. Ask him if he has both motors back yet, or if he's still stuck with just one.

[BigBeakie]

Quote:
Originally Posted by BigBeakie View Post
Well 44CC that's interesting because I have an invitation from Neil to go see his boat and EP and he is very enthusiastic about it. So there seems to be a disconnect here between what you have just said and what I have heard about his current situation, so I'll check it out and get back to you on that.

However these are the figures that he is reporting & that he is saying should be written up by a journalist for a sailing mag, so again, I'll check it out and report the results, hopefully before too long.

We spoke to him about two weeks ago. Give him a call. I can give you his number if you like. Ask him if he has both motors back yet, or if he's still stuck with just one.

Well I just had a nice chat with Neil about his experience with the Torqeedo Cruise 4 motors, and the situation is just as I suspected. Yes, he has had the problem with the leaking seal that is a known issue with the original Cruise 4 model. In every case Torqeedo have remedied the problem by either repairing or replacing the motor over a 5 year period !!! The latest incident occurred when he was motoring up the Brisbane River and was hitting the big Blue-white jellyfish, those solid ones about a kilo each, and the prop was hitting thousands of them for an extended period. That caused another very small leak in the seal, and it happened at Christmas so people were away on holidays so he had to wait for the fix.

He sounds very supportive of Torqeedo to me, and thinks the service is exceptionally good. He highly recommended Torqeedo to me, as I am a prospective customer for Torqeedo. Some direct quotes from him, which he approved me to include here were " the Torqeedo's are the best thing about the boat, even considering the seal problems", and " if I was doing another boat I'd put them on again."

By the way, Torqeedo have taken steps to re-engineer the Cruise 4 that fixes the seal issue, and I believe Neil will be getting them from Torqeedo.

So that's a wrap from me. What I heard is a company that is standing behind it's products 110%, and going to extraordinary efforts to keep it's clients happy.

Honestly, 44' CruisingCat, what else as consumers can we expect?

[Seaslug Caravan]

Originally Posted by 44'cruisingcat

We spoke to him about two weeks ago. Give him a call. I can give you his number if you like. Ask him if he has both motors back yet, or if he's still stuck with just one.

Is this the Neil guy from "cool cats" were talking about?
If it is, then 44c is correct in his assertions.
I have also been on his boat up Urangan way a few years back.
He was always extremely reluctant to go for a daysail, as the marina presented
too big a challenge with such tiny motors, on such a large boat.

People love their boats and always focus on the positives. Do some research and ask the right questions. You will learn heaps.

While you are on his boat, check out his trampolines made from
shade cloth. Interesting.

[44'cruisingcat]

Yes I know the jellyfish. I've probably chopped up a few tens of thousands of them myself, without any cracks appearing in my engines.


On a boat motor I'd expect problems like this to be sorted BEFORE I shell out thousands of dollars. As a paying customer I wouldn't expect to be used to beta test the motors for the company.


And that's really what's been happening - the company is using paying customers to test the suitability of the cruise 4 for big boat application.


These problems have been ongoing for years. School's Out had some similar issues, (as well as others) and it seems they're still happening. School's Out dumped the Torqueedo's about 5 years ago BTW.


Neil certainly seems to have changed his tune. As I said, pretty much his last words to us as we were leaving on our dinghy were that he's going to be investigating outboard motors, as the cost of the constant ongoing repairs to the Torqueedos would be unsustainable. Maybe Torqueedo have extended his warranty?


But as I've said before, if you're not willing to learn from the experiences of others, go ahead and make the same mistakes.... er, decisions.

[leftbrainstuff]

Originally Posted by BigBeakie

Gents

"Just a few back of the envelope calculations using electric motors."
Back of the envelop EP system design isn't good enough , you actually have to use realistic data to make good choices on the important parmeters like 1. What motor power do you need for a specific boat? 2. What motoring time/range will you need? 3.What battery capacity (and therefore charging capacity) will be needed for the scenarios that will be encountered?

"Becalmed for two days on a passage - even assuming low cruising speeds like 2Kn motoring - approx. 400KWH over 24 hours"
Where are you coming up with these figures? Your 2Kt scenario using 17kWH is way off base, unless they are massively inefficient motors on too big a boat.
Here's a real example on a 44 Oram in Caloundra; he has Torqeedo Cruise 4.0 motors for the last 4 years. He has 500kW solar and a 6.5kW diesel generator. Boat is fully loaded for cruising and on the solar alone he is getting 2.5kts, continuously. Note well, on solar alone, which he calls "motoring from the roof." Using the genset for motoring he is getting 5.5 to 6 kts. He hardly ever uses the gennie, in fact he is still using the original diesel fuel from his first fill up 4 years ago which was 60 litres!! He is wondering about the effective age of diesel fuel. Does that answer where all this huge amount of power is coming from?

Motoring into 40Kn where sail cannot be used - ~30Kw per hour.
Again, an over estimation of what is required. Are you trying to portrat EP in the worst light possible??? Why can't sail be used, BTW?
In my case I will be using 30kW (40 HP) motors, but the system will draw 6kW per hour for extended motoring, using one motor at a time while the other side charges from the 6.5kW gennie. The Kiwiprop will be sized to be optimized for cruising speed (6 to 7 knots) using 6Kw/H. That gives me 3 hours on each motor from the propulsion batteries before charging is required. That's 6 hours of silence, no fumes, no vibration at cruising speed.There is no need to go full speed ahead, especially into 40Kt chop! So at slower speeds I will get alot more range and motoring time on the batteries alone. Add the gennie to motor continuously, until the diesel runs out, same as anybody. Except that under solar alone I will still be making way

Protection from lee land in rough conditions where motors must be used for safety - ~20KW per hour.
Yes agreed, but for how long do you need full speed until you get cleared of lee shore and you can then sail? I'll have about 1.5 hours at full speed. But why would I need full speed? The thrust from the right combination of electric motor and prop is just awesome, and progress against high winds, adverse sea state, tidal currents etc. is really impressive with EP at very modest battery draw.
So I would like to hear from cruisers who have motored at full speed. Why was it necessary, and what was the longest time required?

Where pray tell is all of this power coming from? Where does it come from when you are motoring at night? Where does it come from when you need maximum power to keep the boat safe?
I think I have adressed these questions. It comes from batteries, and it comes from a generator when the motoring requirement goes beyond what can be delivered from the batteries alone, ie the gennie charging the batteries. Pretty simple, really.

All very nice if you motor out for the day, sail around for a day or so, and come back home, but totally impractical for anybody out cruising.
OK, whatever you say. Let's see some analysis that uses real data that demonstrates your point.

Sure, maybe in 5-10 years, and that is great if you can wait 5-10 years. For most of us that want to be out cruising now, there is no option but diesel motors.
Really??? Good EP is available right now, for those who wish to be serious about it, and where the TCO makes sense financially. If you motor quite a bit, it makes perfect sense and is, in fact, a money saver. The numbers aren't hard to run. A cursory look at what is happening in the commercial boating scene shows hard headed business analysis is choosing serial electric hybrid over ICE diesel for the benefits and cost savings.

I'll just comment that there really seems to be alot of FUD surrounding EP. Maybe it's the failures that are disproportionately influencing opinions. Like Lagoon's inadequate attempt, or bad system design by those that just cobble it all together without the necessary safety, robustness and fault tolerant aspects built in. Dunno, but just saying basically it can't work, seems a bit like naive scepticism to me.

Some good data there. The FUD will slowly dissapear as examples like this appear.

Sent from my SM-N900T using Cruisers Sailing Forum mobile app

[tightgroup]

Its seems to me that match is not a forte when it comes to the calculation of energy requirements.
EP uses 9.6Kw @ 48 volts giving the equivalent of 17 -25 hp and yet people are saying that this kind of power can be regenerated in a matter of hours with solar panels..

please explain how I can regen power without using diesel fuel ?? And If i have to run a gennie, the process losses efficiency. Ergo more economical to run a good diesel engine.

Anyone care to factor in the extra weight of batteries being able to sustain 8 hrs of run time.