Electric propulsion in the future

[wholybee]

Originally Posted by Lindsaymcm

I am impressed by Lindsay's claim of burning only 3.5 litres an hour at 8 knots in something with a waterline length in the vicinity of only 30 feet. That's a speed/length ratio of 1.46, which is very high, and a fuel burn of less than half a litre per knot-hour at that ratio implies a remarkably efficient hull design.

Yeah it’s a 1912 design of a type known here as a “settler’s launch”, originally powered with a c.20hp petrol engine. Very narrow beam (2.4m) and very economical.[/QUOTE]

I have a 31 foot waterline, and burn 2.7l/h to go 7 kts. I think the claim is believable. He is exceeding his hull speed, but not by much. And, he is burning 30% more fuel than me.

[more]

Originally Posted by Lindsaymcm

Kia Ora (greetings) from New Zealand, where I own a replica classic 33-foot launch powered by a 39hp Lombardini diesel which drives her at 8 knots burning 3.5 lph for a range of approx 600 nm.

Looking ahead 20-30years to the time when the engine may need to be replaced I’m wondering if electric propulsion may be feasible by then.

It seems to me that if electric cars are already capable of 300-400km range, and buses can already run all day on batteries, and both ferries and heavy vehicles are all in development, then the rapid pace of change suggests that by 2040 a small diesel could be replaced by sparky.

Thoughts?

3,5 lph x 3,3 kwh = 11,55 8nm = 1 nm 0,69 kwh 1 nm +10% 0,75-0,8 kwh nm

600 nm x 0,75 +22% 450 +-550 kwh battery bank

but in reality for flat sea you don't need more of 4-6 kw motor maybe less

simple buy Torqeedo Cruise 10.0 T try in real word buy good current longer and later sale this Torqeedo like used

[Larryo]

Wow, if one really looks at the numbers, electric is far from prime time for most boat applications.



It does come into play in some cases.... my electric bike (tandem) takes 2 of us 40 miles on a charge and works great. That's it for me. I don't want to be limited to 4 kts in a dinghy or 5 kts in my boat. Dual power doesn't cut it and is way too expensive for what you get.



Hard to beat a good old diesel for reliability, power and predictability to push a boat around. It's a proven concept and pretty much the gold standard in marine propulsion.


Electric will get there, but will take time, or something else will show up.



Keep drilling, baby, we'll need it for the next 30 to 40 years.



Coastal crusing power boater.

[danstanford]

Originally Posted by valhalla360

I would love a viable electric propulsion system. Electric motors are simply better.

What aggravates me is the unicorn fart proponents who refuse to run the actual numbers.

Sure you can use a generator to charge the batteries but it's more efficient to just connect the ICE directly to the prop shaft.

Electric if viable now if you only need power to get in and out of port and are willing to sail regardless of conditions otherwise. The problem is 90% of cruisers don't do that when coastal cruising and the rare cruiser who does sail in all conditions, doesn't use much diesel anyway, so they aren't gaining much and killing the resale of the boat.

I think for a low speed dingy (vs having a 2hp outboard), electric propulsion is viable.

I also think for canal cruisers it could be viable. Often there is a speed limit well below hull speed and you spend a lot of time not moving as you go thru locks, so it takes less power and significant periods of time, the motors are drawing nothing...plus depending on the waterway, there is often access to power outlets, so you aren't entirely dependent on solar which has significant limitations.

How is this for numbers? I sail at least once a week and often more than that and so far in 3 years of sailing I have used less than 2 gallons of gasoline. The electric with an auxiliary may be less efficient in day to day use but this model allows for ice only when needed.

You perfectly make my point above by the way and the unicorn comment is not helpful in the discussion.

[StuM]

Originally Posted by more

3,5 lph x 3,3 kwh = 11,55 8nm = 1 nm 0,69 kwh 1 nm +10% 0,75-0,8 kwh nm

600 nm x 0,75 +22% 450 +-550 kwh battery bank

What are those numbers meant torepresent? They are just a string of meaningless numbers and dimensions.
3.5 lph x 3.3 KWh = 11.55 litres x Kilowatts??? "Kilowatt litres" is a meaningles mix of units. Power x Volume??
8nm = 1 nm is just as nonsensical.

[Pete7]

Originally Posted by Larryo

Wow, if one really looks at the numbers, electric is far from prime time for most boat applications.

Agreed, but could you manage? or even use sails more?

I don't know how much you pay for a litre of diesel in Florida, but if it rose to 4 times the current price would that alter your usage and encourage a switch to electric. The UK is currently paying £1.45 a litre, Europe not that much different. What would it take? not much the taxation process is already in place, just needs tweaking every year until people switch to electric transport.

Pleasure boat consumption is tiny, we will just be swept along.

Pete

[valhalla360]

Originally Posted by danstanford

How is this for numbers? I sail at least once a week and often more than that and so far in 3 years of sailing I have used less than 2 gallons of gasoline. The electric with an auxiliary may be less efficient in day to day use but this model allows for ice only when needed.

You perfectly make my point above by the way and the unicorn comment is not helpful in the discussion.

How is this? It's an example of a very unusual use pattern among cruisers.

I already stated that if you don't use the motor currently, not needing an electric motor is equally viable.

[valhalla360]

Originally Posted by Pete7

Agreed, but could you manage? or even use sails more?

I don't know how much you pay for a litre of diesel in Florida, but if it rose to 4 times the current price would that alter your usage and encourage a switch to electric. The UK is currently paying £1.45 a litre, Europe not that much different. What would it take? not much the taxation process is already in place, just needs tweaking every year until people switch to electric transport.

Pleasure boat consumption is tiny, we will just be swept along.

Pete

Even when we owned a boat with twin V8's, fuel consumption while painful at the fuel dock, never really made up much of the overall cost picture. Even at quadruple the price, fuel isn't a make or break issue.

[more]

Originally Posted by StuM

What are those numbers meant torepresent? They are just a string of meaningless numbers and dimensions.
3.5 lph x 3.3 KWh = 11.55 litres x Kilowatts??? "Kilowatt litres" is a meaningles mix of units. Power x Volume??
8nm = 1 nm is just as nonsensical.

1 liter diesel have 9,8 to 10.56 kWh but on gas station is around 10kwh

best small diesel engine has efficiency on shaft 33% usually is 30-33% normally on huge wartsila 10 000 kwh and up efficiency is around 46-50%
(like volkswagen in USA data show)

[Shaneesprit]

For me it’s a NO maybe there will some miracle discovery in battery Tech but I doubt it.
Batteries only make sense if you have wind or solar to recharge and don’t require any fósil fuel once you need fósil fuel recharge you are kidding yourself- so how this can ever make sense in a boat is difficult to understand.
Hydrogen may offer a solution- but let’s worry about the boat after the revolution unless you’re in need of re power now.

[jeepers]

There is a sailing channel. They have a total electric drive with Regen. They first used a forklift motor & cobbled together a set up. Now with some experience & upgrades they are totally electric (with a Honda genset for back up)
Currently they are near Svalbard north of the Arctic circle and also visiting northern Russia.
Anyhow here is the links;

https://www.youtube.com/watch?v=m1xk_Gxiztk

https://www.youtube.com/watch?v=HouwSrzKvKU&t=13s

[Larryo]

Originally Posted by Pete7

Agreed, but could you manage? or even use sails more?

I don't know how much you pay for a litre of diesel in Florida, but if it rose to 4 times the current price would that alter your usage and encourage a switch to electric. The UK is currently paying £1.45 a litre, Europe not that much different. What would it take? not much the taxation process is already in place, just needs tweaking every year until people switch to electric transport.

Pleasure boat consumption is tiny, we will just be swept along.

Pete

Pete,

I fuel went up 4x I'd still boat... maybe limit my distance at time, but wouldn't switch to electric. And the reason it would rise is only political so when we return to a sensible administration, I'll bet fuel will be reasonable.

The issue with electric is that it's not only not cost effective it just can't do what fuel will do. The physics just don't work out.

Sure, someday we may have a replacement for fossil fuel but we are decades away, and it may not be electric.



Even with total electric there's still a large component of fossil fuels... just can't get away from it.



For now, we need the oil, and need a LOT more of it, and really need politics OUT of it.

[Ydur]

There will come a time when diesel propulsion will no longer be permitted. As is now the case for large ships in certain places and also for smaller ships on some inland waterways. The builders of ships including yachts and sailboats, and the big names from the world of marine engines, know that these days are in sight and are preparing for it. By then the required technology will be sufficiently and economically available. Marinas are going to look different too. Perhaps ship designs as well in a next step.

[more]

EU ban the sale of petrol and diesel vehicles in the EU from 2035 ban the sale of petrol and diesel vehicles in the EU from 2035.
A couple years after 2035 diesel fuel is possible buy-in EU only in pharmacy

[valhalla360]

Originally Posted by Ydur

As is now the case for large ships in certain places and also for smaller ships on some inland waterways.

Can you name these ships or locations?

I'm aware of one ferry in Norway that has a 2 mile route with massive high speed chargers on both ends but I've yet to hear of a commercial cargo ship capable of hundreds of miles let alone a mandatory govt requirement for such.