Sail boat engine choice - electric or diesel

[Tigue]

I sail on the Columbia River with a constant 2 knots of current and even as a day sailor 2 hours of propulsion would not be adequate.

Coincidentally I just had dinner last night with a friend who is a career expert on electric vehicles and he said full size freight trucks will have electric motors by the year 2023 with a range of 250 miles fully loaded.

So if you ask this question 3 years from now you'll get completely different reply's as the advancements in the technology is very rapid.

[Dave_S]

I might consider buying a boat with electric but I would not pay more for it in fact I would expect to buy it cheaper.

It comes down to how much power you can generate. I don't believe you can generate enough power on a boat that size to cruise without restrictions using electric motors unless you have a generator and I would want the generator matched to the motor so I could motor at 6kn for an unlimited time and have more power in hand if needed.

Then you have to consider the weight, all this is not light.

[Shaneesprit]

I couldn’t day sail with 2 hours of power, that I probably used for cooking and had zero left.
I have only been out twice this once was a day out and a day back, but the wind and tide was against me on the way back so I spent several hours I’m on the motor.
My point is you need to have batteries to last the same amount of time as the fuel you would normally carry!
For me that’s 60 litres max and 20 litres minimum.
I am not going to sea with less than 20 litres of fuel.
Only a little boat so I can probably last 8 to 10 hours on that. To go with 2 hours is a joke.

[Mauruuru]

So at the outset let me just say I am not interested in having an argument with the anti-electric propulsion crowd or with the carbon drunk luddites.E-propulsion is not for everyone-now-but eventually it will be the standard for auxilliary power.
Suffice it to say, as a career long electric power engineer, solar RE developer,and sailor that I believe the technology is 1) game changer 2) mature enough to be a simple DIY project 3) cost advantageous from a life cycle cost analysis before even considering external environmental or societal benefits.
And your protestations are ultimately futile.

[Shaneesprit]

Originally Posted by Tigue

I sail on the Columbia River with a constant 2 knots of current and even as a day sailor 2 hours of propulsion would not be adequate.

Coincidentally I just had dinner last night with a friend who is a career expert on electric vehicles and he said full size freight trucks will have electric motors by the year 2023 with a range of 250 miles fully loaded.

So if you ask this question 3 years from now you'll get completely different reply's as the advancements in the technology is very rapid.

No not at all
Those Trucks already exist, Tesla already makes an Electric truck not a pickup but a big rig and it can go for 4 hours and charge in 30 mins - absolutely a fantastic feat. However it has to be within a 4 hour drive of a charge point, now that charge point is huge and huge amounts of power.
The future of long distance travel is not electric! That’s just everyone jumping on the bandwagon as people always do, there is the longest line of so called Green solutions that end up as disasters out there - I can list them if you like.
Let’s have a try at that.
So
1) 1980s we are cutting down to many trees make everything out of plastic instead!
2) 1990s Catalytic converters on petrol engines - keeps the Green Party quiet while increasing fuel consumption by 25% - well that kept the oil companies happy 👍
3) unleaded fuel - nicely done away with by the need of the catalyst, oh 😯 but we could of done that anyway doh 🙄
4) oh dear there is plastic in the sea, omg I know let’s make the plastic biodegradable- that way none of the stupid people will be able to see it.
5) hey electric drive - yep you make a car that in 10 years has a range of 12 miles 👏 yet I still have the same car I had before you even made that one and it works just fine.
6) still too much plastic - well let’s make the plastic last longer - see plastic bag production down massively - I mean we are still using the same amount of plastic, just in less bags.
7) hey electric drive - yep we can make cars that won’t reach your destination, OK well Tesla does but that’s limited, just how many Nuclear power stations do you need to power today’s road network?
Here in the UK that number = 3 but that’s ok because in 20!years will have 1 new one and we will only be short of 2 more except that we will need more by then and we’ll the old ones will need decommissioning!
The only power is oil until hydrogen arrives, hydrogen will only really be viable if we can produce more electricity than we need from clean sources, as it takes more energy to produce hydrogen than it gives back! and fundamentally the same is for Electric propulsion!
Electric drive - battle ships use this, they run on diesel and convert it to electric!
Oh and the next disaster on it’s way is tighten the building emissions regulations until only electric is viable! Sounds great because all that electric generation is someone else’s problem, so instead of burning gas to produce electricity and the latent heat used for heating, no just electric heating in the building, and then backup power on the grid with gas that produces all the heat except that the grid generation heat is dumped and not utilised!
I like the idea of silence though. Not a fan of listening to a diesel powered sailboat, Bring on hydrogen?

[Mauruuru]

maybe you would be surprised to know that the US Navy use diesel gen sets driven at constant rpm to drive generators and motors .... is to power ship board ac/dc power and PROPULSION MOTORS! Why, the answer is simple maximum efficiency. A Carnot cycle engine has a max theoretical efficiency around 30%-driven by extreme differences in inlet and exhaust temperatures. So give it 30% then realize max torque from a diesel occurs around 60-70% of full rpm whereas a high (90+%) motor delivers 100% of torque from 1 to top rpm. If you bothered to do the research and ask the questions you might actually come to a different conclusion! Oh yes then you opinions might take some woirk to develop.

[Mauruuru]

then do it

[Shaneesprit]

No I totally agree
3 true statements, to make a solar boat work you need an 80ft Catamaran without a mast!
That will get you 6 knots in a warm climate., probably more in short bursts, the one thing with electric drive is huge instant power it just doesn’t last - you could try harnessing the wind that might work!
Presently I am experimenting with this new tech involving sails, revolutionary don’t you know 😂

[Dave_S]

Originally Posted by Mauruuru

So at the outset let me just say I am not interested in having an argument with the anti-electric propulsion crowd or with the carbon drunk luddites.E-propulsion is not for everyone-now-but eventually it will be the standard for auxilliary power.
Suffice it to say, as a career long electric power engineer, solar RE developer,and sailor that I believe the technology is 1) game changer 2) mature enough to be a simple DIY project 3) cost advantageous from a life cycle cost analysis before even considering external environmental or societal benefits.
And your protestations are ultimately futile.

My understanding is that there is not too much more we can improve on what we have. That solar panels and electric motors are within a couple of percent of maxed out for efficiency which leaves batteries to make gains but they are only the storage in the middle. If the amount of energy you make and the amount you use are going to be fairly constant where do you see the improvements ?

[Shaneesprit]

Originally Posted by Mauruuru

maybe you would be surprised to know that the US Navy use diesel gen sets driven at constant rpm to drive generators and motors .... is to power ship board ac/dc power and PROPULSION MOTORS! Why, the answer is simple maximum efficiency. A Carnot cycle engine has a max theoretical efficiency around 30%-driven by extreme differences in inlet and exhaust temperatures. So give it 30% then realize max torque from a diesel occurs around 60-70% of full rpm whereas a high (90+%) motor delivers 100% of torque from 1 to top rpm. If you bothered to do the research and ask the questions you might actually come to a different conclusion! Oh yes then you opinions might take some woirk to develop.

All modern Navy ships use diesel electric not just the US and at least one navy knows all about running out of diesel power for your electric drives. Because like you pointed out a motor delivers its power almost instantly, where as an engine cannot. I wouldn’t have to research the subject It’s second nature to me, I don’t design but I spend my life reviewing Simular issues on land.

[chrisr]

diesel - electric configuration is common in passenger ships due to the lesser vibration

gas turbine - electric is also used.

wonder how that would suit a yacht ?

cheers,

[waterman46]

Originally Posted by Tigue

I sail on the Columbia River with a constant 2 knots of current and even as a day sailor 2 hours of propulsion would not be adequate.

Coincidentally I just had dinner last night with a friend who is a career expert on electric vehicles and he said full size freight trucks will have electric motors by the year 2023 with a range of 250 miles fully loaded.

So if you ask this question 3 years from now you'll get completely different reply's as the advancements in the technology is very rapid.

That electric truck (and we already have electric buses in Oakland that run all day on one charge) will be plugged into a big electric outlet every night, for about 12 hours. I wish I could plug in like that when I'm out on the anchor!

Has anyone mentioned the short battery life and environmental cost that will result from constantly running batteries down every time an electric powered boat goes out even for a daysail?

[newhaul]

Originally Posted by Shaneesprit

All modern Navy ships use diesel electric not just the US and at least one navy knows all about running out of diesel power for your electric drives. Because like you pointed out a motor delivers its power almost instantly, where as an engine cannot. I wouldn’t have to research the subject It’s second nature to me, I don’t design but I spend my life reviewing Simular issues on land.

Not really correct ever heard of this new fangled thing called nuclear ? Or how about a good old fashioned steam boiler system ? Then there is the most used in the us Navy surface fleet gas turbine .

[newhaul]

Originally Posted by chrisr

diesel - electric configuration is common in passenger ships due to the lesser vibration

gas turbine - electric is also used.

wonder how that would suit a yacht ?

cheers,

Depends on if you have room for a t-11 turbine engine . They power the unlimited hydro race boats .

Personally I'm waiting on micro scale nuclear to electric power plants.

[SailMoonShadow]

Originally Posted by newhaul

A diesel will get you out of trouble if you find yourself in it.

I don't see that a diesel would be any better than electric in that scenario.

Originally Posted by newhaul

There are places where you would literally not be allowed to go with an electric drive due to the lack of range .
Don't try to go through the Panama canal or the Suez canal with electric you don't have the required range without diesel generators.
.

That's interesting, I hadn't heard that, thanks for the tip.

On the other hand, what I have heard about the Panama is that yachts are generally rafted in threes with the middle boat providing the propulsion so I would have thought that there's nothing to stop an electric powered boat being on the outside in that configuration. I'll have to investigate!