Considering going Electric

Loren Beach

O34 - Portland, OR
Senior Moderator
Blogs Author
Over the decades I have found that lots of other folks have read a version of that fable about the "elephant and the blind wise men" as it sometimes was referred to. I also recall my irreverent thought :) at the time... that there probably was a sixth man....... who was at the rear of the beast and grabbed its privates and before he could say anything about his perceptions was promptly stomped to death! :D

(It's amazing what lingers in the brain after a 'higher' education, over 50 years ago. Actually my subsequent military service was at times an informal advanced course in behavior & communication!
I must have passed - was not harmed by friend or foe.) :rolleyes:
 
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saphira36

Junior Member
I want to thank everyone for the in depth thought and feedback on this topic and consider the issue settled.

The common thread seems to be that my diesel is more than likely in good enough shape to warrant a bit more investment and should serve me for a good while. I'm going to hold course on that and see where it takes me. The electric option does intrigue me, and I'll continue research and watching where things go, but my priority is to get out on the water ASAP and sail!

Thanks everyone!
 

Teranodon

Member III
We have 1510+ hours on the motor so far. No, our first set of AGMs were replaced last year with LiFePo. Last year I sailed from Galveston Bay to Maine and back down to Florida again, lying Key Biscayne as we speak.

The point being that I don't comment on E27 questions because I don't have an E27. I don't have a water heater, but I'm not posting on threads about water heaters about how unnecessary they are. The intent of this forum is to help fellow Ericson boaters with shared experiences of our boats and the equipment on them. What gets old is reading people's opinions about equipment that they don't own or have no experience with. What is it about this topic that compels these posts?
OK, let me try to pose a question based on my experience. Some years ago, I was sailing in the Med, a few miles off Cap Sicié. Without warning (or a forecast) a mistral kicked up. 20-25 knots, big waves. Two of my crew got seasick and, anyway, I had to get back to Saint-Cyr. So I ran the diesel for about 4 hours, near full throttle. This is the kind of thing that has happened to me many times (for example, in the Northwest Passage, in driving snow). It's less likely here in the San Juans, where forecasts are reliable and there is usually nearby shelter. But anyway, here is the question that others have already asked: what is the range of your boat in dangerous adverse conditions? And please take an even strain. We are all competent, experienced sailors here.
 

gadangit

Member III
OK, let me try to pose a question based on my experience. Some years ago, I was sailing in the Med, a few miles off Cap Sicié. Without warning (or a forecast) a mistral kicked up. 20-25 knots, big waves. Two of my crew got seasick and, anyway, I had to get back to Saint-Cyr. So I ran the diesel for about 4 hours, near full throttle. This is the kind of thing that has happened to me many times (for example, in the Northwest Passage, in driving snow). It's less likely here in the San Juans, where forecasts are reliable and there is usually nearby shelter. But anyway, here is the question that others have already asked: what is the range of your boat in dangerous adverse conditions? And please take an even strain. We are all competent, experienced sailors here.
Hi Stefan-
You mean taking an even strain like this: In my view, electric propulsion is a "boutique" undertaking, to be done for its own sake, not for real-life sailing.

Or this even strained post: underpowered, finicky, "boutique" propulsion system that only works on smallish lakes? Also, given that the technology is evolving all the time, it is almost guaranteed to be obsolete in a few short years.

Or how about post #25? Does that seem like an even strain and approach to the OPs question?

Now on to my hypothetical, your experience.
In that particular situation with 20-25kts of wind and big waves my little electric motor would struggle mightily. I probably wouldn't even bother running the motor? We've been there in those unforecasted conditions with waterspouts and true tornadoes off the coast of Tampa last year. The only way we could see the biggest twister directly behind our boat was during the flashes of lightning at 4am. It was not a waterspout, but a full take Dorothy to see the wizard tornado. Truly horrifying and frightening conditions when 50 miles off the coast. It never occurred to me to turn on the motor, we sailed our little hearts out in the direction that seemed like safety. Full overpowered sail to make the fastest pace we could away from this growing cell. 6 hours later it was still blowing 30 and we were in 10-15' seas. It was like we got transported to the North Sea or something. Forecast was like 10-15kts. Double handed with two frightened cats. We got chased by waterspouts all day long.

We got caught in a 70 kt knock down in the J44. I went below to check the chartplotter at 50kts of wind. I thought I was going to have run around like a mouse on a wheel. We were double reefed, no headsail and sailed it out. No motor came on that I am aware of.

This same J44 had the motor quit coming into the Beaufort, NC inlet in the dark on an outgoing tide. Probably because of how rough it was coming in. It happens. There were just two of us and we quickly and orderly got the smallest stainless steel anchor, cause you can't carry heavy stuff on a race boat, out of it's silly little locker, attached a nylon tape rode, got to be light, and slowed the boat a little as the skipper ran below and magically got the motor running again. The funniest part, to me, was handing me the nylon strapping material and told to quickly tie a bowline. In the dark, on a piece of nylon strapping and in a serious hurry. You want me to do what??? I did and he promptly threw the anchor overboard. Whelp, I hope I got it right! Not a story we wanted to tell the boat owner.

Maybe none of that is real life sailing, who am I to judge? I'm not here to convince anyone that an electric motor is the proper secondary propulsion for everyone and my apologies if that is coming across. Don't want an electric motor, don't get one. Don't want to deal with dangerous adverse conditions, stick closer to shore. Think LiFePo batteries are not for you, then don't get them. But repeating as fact something you read on the internet is no way to give people advice on a forum.

The OP literally asked about going electric and fair weather sailing on a lake. Who better to offer up thoughts on that than the two guys who literally have electric motors in their boats?

Was that even enough?
Chris
 

lindaloo

Member II
The most interesting comment, for me, was gadangit saying this:

“Our fully loaded for cruising 20.000lb boat in flat water uses about 6kw for 5 kts.”

I think that would be one of the biggest bonuses of e-power. The ability to flick a switch and turn the potentiometer up, just a smidge. Like him, we also always have the mainsail up and it never ceases to amaze me how much it helps the motor. There you are sailing, the wind gets lighter and lighter, your speed drops below 2kn. Fire up the beast and even at 1200rpm you are back at 5kn (upwind of course). But the noise, and engine hours. Thought bubble: Can I just bolt a Torqueedo to the transom? Ugly, inelegant, other owners at the marina would point and laugh.

But man, 6kw is about 8hp(?). My E34 might only need 5hp. That Betamarine 20 Hybrid Drive looks like the bee’s knees. Must cost a fortune. Dream on.

Rob
E34, Vancouver BC
 

Teranodon

Member III
Here's my last word. Anyone considering going electric needs to ponder these numbers:

Specific energy of diesel fuel: 3.5 MegaJoules/liter
Energy density of LiFePo battery: 500 KiloJoules/kilogram

Now consider going on a cruise with 10 gallons of diesel in the tank. Turn the crank on the numbers. To get the same amount of energy (i.e., approximately the same range while motoring), you need a fully charged LiFePo battery bank that weighs 58,600 pounds.

No thanks.
 
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poolnickv

Junior Member
Here's my last word. Anyone considering going electric needs to ponder these numbers:

Specific energy of diesel fuel: 3.5 MegaJoules/liter
Energy density of LiFePo battery: 500 KiloJoules/kilogram

Now consider going on a cruise with 10 gallons of diesel in the tank. Turn the crank on the numbers. To get the same amount of energy (i.e., approximately the same range while motoring), you need a fully charged LiFePo battery bank that weighs 58,600 pounds.

No thanks.
The range for a marine diesel engine and an electric motor are not equivalent for the same amount of energy in their respective energy stores. This is because they have different scales of efficiency when it comes in converting the source energy store into mechanical energy. Systems such as those by ocean volt have about 93%energy conversion efficiency. The typical modern marine diesels one would use in these boats probably have 40-55% energy efficiency. There are also torque differences that one should also take into account that have substantial effect in a given sea state. Consequently, those numbers you quoted are substantially inaccurate for equivalent range.

You're right that it would still take more weight if you carry that size of fuel store from the start, but no one with an electric power option does that. You probably also know that those with electric motors are running hydro-generators, wind generators and/or solar regen to maintain their energy store.

If the electric power sailor desires a guaranteed extended long range, they'll use a hybrid approach of using a genset to recharge the battery store. That's actually a common approach since it minimizes fuel usage for a given range due to the higher operational efficiency of each component. That might surprise many since they aren't aware of how efficiencies work in these cases.

Here's an example of a hybrid repower case study from: Yachting World

The main advantage of the system is that it consistently uses around 40% less fuel than a standard diesel engine over the course of a week’s charter.
 

Kenneth K

Contributing Partner
Blogs Author
If the electric power sailor desires a guaranteed extended long range, they'll use a hybrid approach of using a genset to recharge the battery store. That's actually a common approach since it minimizes fuel usage for a given range due to the higher operational efficiency of each component. That might surprise many since they aren't aware of how efficiencies work in these cases.

The main advantage of the system is that it consistently uses around 40% less fuel than a standard diesel engine over the course of a week’s charter.

I don't think I've heard a single proponent of electric power on this website claim it was their desire to "reduce" their consumption of diesel fuel. Most talk about (in addition to whatever it is they specifically like about electrics) eliminating the noise, smell, vibration, maintenance and (perceived) dangers of diesel engines and fuel.

It would seem a tough sell, to me anyway, to say that the real answer is to remove a (perfectly good) diesel engine (and its fuel, cooling and exhaust systems), and replace it with an electric motor, hundreds of pounds of batteries and lots of new wiring, only to then to have to purchase and install a diesel generator (along with its required fuel, cooling, and exhaust systems, noise, smell, vibration, maintenance, perceived dangers and mechanical inefficiencies).

Or maybe it's just me.

A 40% reduction in fuel would save me about 3 gal/$10 per year. What is the 10 year environmental footprint of disposing of an old engine + creating and disposing of two sets of battery banks (assuming a 5 year lifespan) versus burning an extra 30-40 gal of diesel over 10 years?

Nothing is free, or free of impact.
 
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