"Practical " Boat Owner?..

[flaming]

Regardless of how a boat sails in the 4 to 8kts range, when there is no wind and you need to be some place, you motor. When there is 4 kts of wind and a big swell, you motor because you can't keep wind in the sails. I know it has its applications but there will always be a place for diesel power

As long as there is a Diesel power to have a place...

 

[B27]

Regardless of how a boat sails in the 4 to 8kts range, when there is no wind and you need to be some place, you motor. When there is 4 kts of wind and a big swell, you motor because you can't keep wind in the sails. I know it has its applications but there will always be a place for diesel power

I don't think anyone should take it for granted that diesel power for leisure boats will always be allowed and available, let alone affordable.

 

[trapper guy]

Of course the difference with the way an offshore electic powered boat would work is that currently when your fuel is gone, it's gone. In the electric boat a few hours of sailing at decent speeds and the turbine has topped the range up again. Sure in the middle of a massive high that's not a huge amount of use, but everything has upsides as well as downsides.

If the shift away from ICE in all forms of transport means that cruising boat designers are actually required to consider how their boat performs in the 4-8 knots true wind range, instead of just assuming the owner will fire up the donk, then I'm all for it.

hardly.
you simply would not get that much charge back into a battery bank in 24hrs, ive got around 300watts of solar on my boat, it takes days to recharge my bank once its depleted

 

[trapper guy]

i think there is a major difference in opinion of the toodle out of the harbour for a few circuits before returning kinda sailor, and the sailor that wants to get places.
for a weekend sailor i do see electric being viable.
just not for the travelling sailor

 

[flaming]

hardly.
you simply would not get that much charge back into a battery bank in 24hrs, ive got around 300watts of solar on my boat, it takes days to recharge my bank once its depleted

The stats on Oceanvolts website suggest that in regen mode at 8 knots you can put just over 1kW back into the battery. At 10 knots over 3kW. Cruising in a 40ish foot mono requires about 3kW of power.

So a day of sailing at decent but not spectacular speeds in a 40 foot mono and you could motor for another day. If you had a big enough battery to store that much power....

Put simply, the better your boat is at sailing, the more electrical power makes sense.

 

[bergie]

I don't think anyone should take it for granted that diesel power for leisure boats will always be allowed and available, let alone affordable.

Berlin in the 70s reputedly had certain days of the week when combustion engines were allowed to be used. The rest was with sails or muscle power only.

And some lakes in Switzerland have already banned combustion engines.

 

[geem]

The stats on Oceanvolts website suggest that in regen mode at 8 knots you can put just over 1kW back into the battery. At 10 knots over 3kW. Cruising in a 40ish foot mono requires about 3kW of power.

So a day of sailing at decent but not spectacular speeds in a 40 foot mono and you could motor for another day. If you had a big enough battery to store that much power....

Put simply, the better your boat is at sailing, the more electrical power makes sense.

And you believe their figures? Are they independently verified or sales BS?

 

[flaming]

And you believe their figures? Are they independently verified or sales BS?

Who knows? The point is that this is on a seriously steep development curve right now. The tech is getting better and better.

Simply saying "it can't be done" is just a cop out.

 

[B27]

i think there is a major difference in opinion of the toodle out of the harbour for a few circuits before returning kinda sailor, and the sailor that wants to get places.
for a weekend sailor i do see electric being viable.
just not for the travelling sailor

Since people manage to sail around the world using sails only, I think this is nonsense.

It's actually weekend sailing and other trips where there's a tight time constraint to get home or whatever, where a diesel engine is most useful.

Long term cruisers don't usually 'need' to go long distance using diesel.
Weekend JOG sailors place a high value on being able to motor from from a cross-channel race and get to work on Monday.

I choose to have a boat with a decent diesel engine, because it makes life easier, enables me to do the sailing I do.
If I couldn't have a decent engine, I'd do different trips and accept sometimes having to wait for breeze.
People used to sail on that basis.

It's a choice, like when I was 16 I chose to have a two-stroke moped. My 16 year old nephew chooses to have an e-bike.
His ebike doesn't enable him to do the riding I did, but the world has moved on!

 

[DownWest]

so a paddle wheel dropped into the water, may slow a boat by half a knot, but if the result is cost free electrical generation for 30kts, it a win? surely?

the paddle would still generate when the boat was moored up, unless you happen to live in an anomaly spot on earth where water doesnt flow 24hrs a day, every day, just like wind or solar are not available 24hrs a day, any day.

Nope, dropping a paddle wheel into the water creates drag, so the motive power has to work harder to maintain the set speed. You will see a net loss on the idea. Hence my comment on 'perpetual motion'

If you have a swinging mooring and a paddle wheel kit then yes, some 'free' energy, apart from the cost of the kit.

 

[DownWest]

There is another aspect, not mentioned so far but refered to, sort off..
To get efficient e-power in cars, the voltages are quite high, in the hundreds, 800v? I would be very uncomfortable with that in my boat..salt water etc. Just think of a minor leak that happened to get at a part of that system.

Sort of reminded of sailing a boat, way back, to France from Sardinia. It had been sunk, so the engine, a Stuart Turner flat twin, was 'a bit tricky' I managed to get it to work at low power, so it was just to get in, or out, of a port, slowly.
Much like e-power if one spends not too much.

 

[dunedin]

There is another aspect, not mentioned so far but refered to, sort off..
To get efficient e-power in cars, the voltages are quite high, in the hundreds, 800v? I would be very uncomfortable with that in my boat..salt water etc. Just think of a minor leak that happened to get at a part of that system.

Sort of reminded of sailing a boat, way back, to France from Sardinia. It had been sunk, so the engine, a Stuart Turner flat twin, was 'a bit tricky' I managed to get it to work at low power, so it was just to get in, or out, of a port, slowly.
Much like e-power if one spends not too much.

Surely you didn’t miss the voltage point raised in post #88

 

[geem]

Who knows? The point is that this is on a seriously steep development curve right now. The tech is getting better and better.

Simply saying "it can't be done" is just a cop out.

I haven't said it can't be done. I have said it won't work in all applications. Maybe not most applications. It's a bit like the government pushing electric cars. The tech is there but people don't necessarily want it. If you live in a terrace street with on street parking, how do you charge your car? Others think it's great because they have a huge solar array and can charge their car at home on the drive. It's horses for courses

 

[trapper guy]

Nope, dropping a paddle wheel into the water creates drag, so the motive power has to work harder to maintain the set speed. You will see a net loss on the idea. Hence my comment on 'perpetual motion'

If you have a swinging mooring and a paddle wheel kit then yes, some 'free' energy, apart from the cost of the kit.

the drag being the half a knot i mentioned perchance?

 

[ylop]

so a paddle wheel dropped into the water, may slow a boat by half a knot, but if the result is cost free electrical generation for 30kts, it a win? surely?

the paddle would still generate when the boat was moored up, unless you happen to live in an anomaly spot on earth where water doesnt flow 24hrs a day, every day, just like wind or solar are not available 24hrs a day, any day.
so lift the paddle out of the water when sailing? ill wait for the ridiculous objections why that would induce losses into the system

You are talking about this as though you’ve just invented it. Towing a small turbine to generate power has been around for decades. A number of manufacturers now offer bolt on “flip down” regen units (look like half an outboard) or regen back through the prop.

I don’t think anyone claims they work on a mooring - people don’t generally anchor or more in places with those sort of currents.

You can accept that you need to use the boat differently but that isn't comparing apples with apples. We can motor at 5 or 6 kts for days. This gets us out of bad weather or into harbour before night fall or simply motors us through a large high pressure system. These options may disappear with all electric drive

I suspect the vast majority of boats wouldn’t be using it differently though. Just because you happen to motor across oceans most people don’t.

and the sailor that wants to get places.
for a weekend sailor i do see electric being viable.
just not for the travelling sailor

The sailor will be fine - and assuming YouTube is representative of modern cruisers, they’ll spend a lot of time at anchor. But I don’t think anyone has ever said all yachts would become all electric so I’m not sure why people get so angry about other people trying alternative technology.

And you believe their figures? Are they independently verified or sales BS?

Seems like the sort of thing where a magazine article covering the practicalities of installing and owning would be a good idea (to bring us vaguely on topic!)

 

[geem]

You are talking about this as though you’ve just invented it. Towing a small turbine to generate power has been around for decades. A number of manufacturers now offer bolt on “flip down” regen units (look like half an outboard) or regen back through the prop.

I don’t think anyone claims they work on a mooring - people don’t generally anchor or more in places with those sort of currents.

I suspect the vast majority of boats wouldn’t be using it differently though. Just because you happen to motor across oceans most people don’t.

The sailor will be fine - and assuming YouTube is representative of modern cruisers, they’ll spend a lot of time at anchor. But I don’t think anyone has ever said all yachts would become all electric so I’m not sure why people get so angry about other people trying alternative technology.

Seems like the sort of thing where a magazine article covering the practicalities of installing and owning would be a good idea (to bring us vaguely on topic!)

As I said, as an owner of a towed hydro generator, they don't produce much power in the scale of things. A good one should produce 200Ah per day at 12v in good sailing conditions. When you look at the likes of Oceanvolt, I am not convinced that these large regeneration figures are real. The drag of a propeller creating 1kw will be immense. Converting from a fixed three blade propeller to a folder, typically gives 0.5/1kt increase in boat speed. A propeller that is optimised to pull 1kw will have substantial drag. Who wants to pull their boat speed down by a knot or 2 on passage?
I have no love of magazine articles written where they are reviewing products and the product is advertised in the magazine. You know its BS and there will be nothing negative said about the product. Same as all these boat reviews saying how much faster the boat is than the last one. The magazines have been spouting the same spiel since the 1970s. Modern cruising boats should all be doing 100mph now if you believed the reviews

 

[trapper guy]

You are talking about this as though you’ve just invented it. Towing a small turbine to generate power has been around for decades. A number of manufacturers now offer bolt on “flip down” regen units (look like half an outboard) or regen back through the prop.

I don’t think anyone claims they work on a mooring - people don’t generally anchor or more in places with those sort of currents.

not like i invented it, its just a suggestion.
generating enough electricity is a mission of mine, ive got 300watts of solar, charging a 460ah battery bank.
or should i say TRYING to charge a battery bank.
i just cant see solar ever being enough to power an electric drive in any meaningful way

and by your final comment i take it you are stationed daaan saarf, where there is no tide to speak of.
im in the bristol channel, and there are plenty of places with 'those sorts of currents'

 

[trapper guy]

I have no love of magazine articles written where they are reviewing products and the product is advertised in the magazine. You know its BS and there will be nothing negative said about the product. Same as all these boat reviews saying how much faster the boat is than the last one. The magazines have been spouting the same spiel since the 1970s. Modern cruising boats should all be doing 100mph now if you believed the reviews

recently looked up reviews on savvy navvy, nothing but glowing reports of a fantastic system.

the reality for me, because i subscribed to it for a year, was frustration, irritation.

pick up your phone to check on progress, inadvertently cancel the plot. try to replot, it now needs to recalculate the plot despite me having saved it beforehand, but im more than 5 mile offshore with no signal....

im told that plotting a course ahead of your current position IS possible, though in a year i never figured out how, despite numerous attempts it always calculated the plot from my current position.

i sacked it off after the year, going to try navionics.

helping to mislead your readership in favour of satisfying the requirements of the advertiser isnt the best modus operandi, in my mind.

puts me in mind of the washing powder adverts, ive been seeing 'now whiter than white' and 'new improved formula' since the 70's, ive been expecting whites to be so white that they are translucent

 

[ylop]

im in the bristol channel, and there are plenty of places with 'those sorts of currents'

Absolutely not, there’s plenty of big currents here - but:

1. We don’t tend to anchor of moor in the areas with 3+knot currents. My mooring has about 1knot at peak springs
2. Most systems for generating power by towing a prop through the water seem to need around 4 knots to be able to generate power (a prop will turn with no load on it but as soon as you connect an alternator it is effectively a brake).
3. Even if you had a system/location when it would work the boat will tend to move to minimise its drag, ie turn until there is least resistance on the turbine! The wind makes this even harder to manage. Fixed tidal power gen needs “forced” into the flow.

If you want to see this - if you have a non-feathering prop when under sail in neutral you can see/hear the prop spinning. You won’t normally notice this on a mooring / anchorage / marina - and that’s with no load on the prop.

 

[trapper guy]

Absolutely not, there’s plenty of big currents here - but:

1. We don’t tend to anchor of moor in the areas with 3+knot currents. My mooring has about 1knot at peak springs
2. Most systems for generating power by towing a prop through the water seem to need around 4 knots to be able to generate power (a prop will turn with no load on it but as soon as you connect an alternator it is effectively a brake).
3. Even if you had a system/location when it would work the boat will tend to move to minimise its drag, ie turn until there is least resistance on the turbine! The wind makes this even harder to manage. Fixed tidal power gen needs “forced” into the flow.

If you want to see this - if you have a non-feathering prop when under sail in neutral you can see/hear the prop spinning. You won’t normally notice this on a mooring / anchorage / marina - and that’s with no load on the prop.

the turning prop was something i noticed on my competent crew vessel. my own has a folding prop so i never noticed it, but the churning sound was very much evident on the training vessel