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Moderated ECO 75 solar electric built in NZ

 

?

It is surprising how many of my boats are sailing the world, and I know nothing about them.

Here is a solar electric ECO 75 sailing in New Zealand. I found the article and the photos in the Junk Rig Association magazine.

Interesting is his way of living and trying to have a low footprint. I will try to find him so that I can use his article. Here are some important facts.
The boat is built according to plan in12 weeks spread over a year. He added Kevlar on the bottom.
Only four of the 6 solar panels are used to recharge the Lithium batteries. Boat speed with the setup as is today around 5 knots.
Can be about 8 knots with a second e-motor. He is also thinking to use a 20m2 kite for long distances.
I will try to find the owner and get some more information.

ECO75sunshine.jpg
ECO75solel.jpg

 

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-------- Message d'origine --------
De : Bernd Kohler <ikarus342000@...>
Date : 12/03/2022 21:43 (GMT+01:00)
Objet : [Special] [K-Designs-Multihull-Sailboats] ECO 75 solar electric built in NZ

?

It is surprising how many of my boats are sailing the world, and I know nothing about them.

Here is a solar electric ECO 75 sailing in New Zealand. I found the article and the photos in the Junk Rig Association magazine.

Interesting is his way of living and trying to have a low footprint. I will try to find him so that I can use his article. Here are some important facts.
The boat is built according to plan in12 weeks spread over a year. He added Kevlar on the bottom.
Only four of the 6 solar panels are used to recharge the Lithium batteries. Boat speed with the setup as is today around 5 knots.
Can be about 8 knots with a second e-motor. He is also thinking to use a 20m2 kite for long distances.
I will try to find the owner and get some more information.
 

Beautiful boat!!! impressive how fast he managed to build.
 

Talking about your boats around the world, have you seen this one?
Sailing on 30knots wind...

??

This is a cool video
.
 

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??? We are reaching the point where electric power will soon "pencil" at least as auxiliary.?? Weight of the batteries is the killer here, especially where multihulls are concerned with their minimal load capacity.?? Let's say 20kwh of lithium ion batteries are at about 120kg......... a fairly realistic figure.?? 1 hp is about .75 kw.? Lets say you are running 5 hp = 3.75 kw??? 20kwh is 20 kw for one hour.?? That works out to 5.3 hours at 5 hp out of 120kg or 264 lbs.??? That means that to have a steady 5 horsepower output for 10 hours is going to take almost exactly 500 lbs of batteries.?? That's not that bad when one considers engine weight and fuel weight for a gas or diesel engine.?? But it's only 10 hours.?? With sufficient solar power one could get quite a bit of propulsion direct on a clear day.?? Let's say 18w per square foot of solar panel, and that's 208.3 square feet of panel.? That would be a solar array of 20.8' x 10' or 12' x 17.36'... etc.? That's a LOT of solar, and it's NOT charging batteries, just delivering 5 HP to the prop.??

??? It's obvious that at this point we can only use solar electric along with wind realistically.?? It can provide additional propulsion in light winds, propulsion in port, get us through the doldrums perhaps, and perhaps break our bond with fossil fuels.? We can run the galley, etc with battery electric, and we can also generate with regen, or a wind charger.?? And we can run the watermaker......... all depending on conditions.??? It means that you can pull into port, set anchor, and NOT haul fuel, propane, or water when you are voyaging.??? This is exciting stuff if you look at the whole picture.? We can also look at increasing solar panel efficiency, and battery density to the point that this will make more and more sense over time.

??? ??? ??? ??? ??? ??? ??? ??? ??? ??? ??? ??? ??? ??? ??? ??? ??? ??? ??? ??? ??? ??? ??? ??? ??? ??? ??? ??? ??? ??? ??? ??? ??? ??? ??? ??? ??? ??? ??? ??? ??? ??? ??? ??? ??? H.W.


On 3/12/22 1:43 PM, Bernd Kohler wrote:

?

It is surprising how many of my boats are sailing the world, and I know nothing about them.

Here is a solar electric ECO 75 sailing in New Zealand. I found the article and the photos in the Junk Rig Association magazine.

Interesting is his way of living and trying to have a low footprint. I will try to find him so that I can use his article. Here are some important facts.
The boat is built according to plan in12 weeks spread over a year. He added Kevlar on the bottom.
Only four of the 6 solar panels are used to recharge the Lithium batteries. Boat speed with the setup as is today around 5 knots.
Can be about 8 knots with a second e-motor. He is also thinking to use a 20m2 kite for long distances.
I will try to find the owner and get some more information.
[email protected]
 

From: [email protected] [mailto:[email protected]] On Behalf Of Bernd Kohler
Sent: Sunday, 13 March 2022 9:43 a.m.
To: [email protected]
Subject: [Special] [K-Designs-Multihull-Sailboats] ECO 75 solar electric built in NZ

?

?

It is surprising how many of my boats are sailing the world, and I know nothing about them.

Here is a solar electric ECO 75 sailing in New Zealand. I found the article and the photos in the Junk Rig Association magazine.

Interesting is his way of living and trying to have a low footprint. I will try to find him so that I can use his article. Here are some important facts.
The boat is built according to plan in12 weeks spread over a year. He added Kevlar on the bottom.
Only four of the 6 solar panels are used to recharge the Lithium batteries. Boat speed with the setup as is today around 5 knots.
Can be about 8 knots with a second e-motor. He is also thinking to use a 20m2 kite for long distances.
I will try to find the owner and get some more information.
 

I think your calculations are in the ball-park except for discharge of 20kWh of LiFePO4 batteries. For long life, they should not be discharged more than 80%. This means a 20kWh battery bank can only use about 16kWh.

All boats also need reserve capacity for bad weather or other considerations. You are right to ignore this when calculating range. Thus we can directly compare range of vessels with varying power systems. But the real range available to prudent mariners is less.

Recharge is a challenge. Though LiFePO4 batteries charge relatively quickly, they are extremely slow to re-energize compared to liquid fuel. Also, electrical re-fueling infrastructure is extremely poor compared to liquid fuel. Electric boats can rarely pull up to a recharging station to re-energize batteries.

Don't get me wrong, I like electric power. I just do not think most boaters are ready for it. Here where I live at latitude 48, with predominately marine cloud cover, solar panels are less effective. I used 170 Watt solar panel for daily dependable 40 ah battery recharge. There are tens of thousands of miles of semi-protected shoreline to explore here. There are almost no charging stations along all that shoreline.

I know that most boaters are under power for relatively short periods. For them, solar charging systems are more useful. Alternatly, charging stations allow recharge if available. But this limits where the boat can operate since it needs to stay within range of the charging station.

One last thought. Where I live, most boaters have more than one propulsion system. Though there are many anchorages, current and weather considerations make back-up propulsion prudent. So pairing electrical propulsion and sail or diesel and electrical pairing are more suitable than electrical propulsion alone. Thus, a boat could use primarily electrical propulsion with one of these other systems for back-up. This eliminates some of the drawbacks of electrical propulsion alone.

David M
On Sunday, March 13, 2022, 01:12:37 AM PST, Gerridae <owly@...> wrote:


??? We are reaching the point where electric power will soon "pencil" at least as auxiliary.?? Weight of the batteries is the killer here, especially where multihulls are concerned with their minimal load capacity.?? Let's say 20kwh of lithium ion batteries are at about 120kg......... a fairly realistic figure.?? 1 hp is about .75 kw.? Lets say you are running 5 hp = 3.75 kw??? 20kwh is 20 kw for one hour.?? That works out to 5.3 hours at 5 hp out of 120kg or 264 lbs.??? That means that to have a steady 5 horsepower output for 10 hours is going to take almost exactly 500 lbs of batteries.?? That's not that bad when one considers engine weight and fuel weight for a gas or diesel engine.?? But it's only 10 hours.?? With sufficient solar power one could get quite a bit of propulsion direct on a clear day.?? Let's say 18w per square foot of solar panel, and that's 208.3 square feet of panel.? That would be a solar array of 20.8' x 10' or 12' x 17.36'... etc.? That's a LOT of solar, and it's NOT charging batteries, just delivering 5 HP to the prop.??

??? It's obvious that at this point we can only use solar electric along with wind realistically.?? It can provide additional propulsion in light winds, propulsion in port, get us through the doldrums perhaps, and perhaps break our bond with fossil fuels.? We can run the galley, etc with battery electric, and we can also generate with regen, or a wind charger.?? And we can run the watermaker......... all depending on conditions.??? It means that you can pull into port, set anchor, and NOT haul fuel, propane, or water when you are voyaging.??? This is exciting stuff if you look at the whole picture.? We can also look at increasing solar panel efficiency, and battery density to the point that this will make more and more sense over time.

??? ??? ??? ??? ??? ??? ??? ??? ??? ??? ??? ??? ??? ??? ??? ??? ??? ??? ??? ??? ??? ??? ??? ??? ??? ??? ??? ??? ??? ??? ??? ??? ??? ??? ??? ??? ??? ??? ??? ??? ??? ??? ??? ??? ??? H.W.


On 3/12/22 1:43 PM, Bernd Kohler wrote:

?

It is surprising how many of my boats are sailing the world, and I know nothing about them.

Here is a solar electric ECO 75 sailing in New Zealand. I found the article and the photos in the Junk Rig Association magazine.

Interesting is his way of living and trying to have a low footprint. I will try to find him so that I can use his article. Here are some important facts.
The boat is built according to plan in12 weeks spread over a year. He added Kevlar on the bottom.
Only four of the 6 solar panels are used to recharge the Lithium batteries. Boat speed with the setup as is today around 5 knots.
Can be about 8 knots with a second e-motor. He is also thinking to use a 20m2 kite for long distances.
I will try to find the owner and get some more information.
 

Hi Bernd,
I hope he has payed for the plans....!
With what brand and type of motor do he reach this 5 knots of speed, and is this full throttle?

Groeten,? Jack
 

I have been running exclusively on solar electric since 2016. A lot of learning curves to overcome. My boat was a small one 18' and a mono hull with a hull speed of 6 knots. My solar panel capacity in 2018 was 860 watts but I would use a 50% rule for estimation of power as you never get full capacity from a solar panel due to time of day and angle of the sun. My motor was a Torqeedo Cruise 2.0 which is rated at 5 HP but to cruise at 4.5 knots it would be about 40%. My longest outing was 16 days using only solar electric power.
If you plan to go on an extended trip you need to plan to balance wattage being generated through the day and wattage being drawn by the motor. Speed vs power usage follows an exponential curve. On a sunny day (in Aug) I could cruise for 8 hours at 4.5 knots and after stopping the batteries would continue to charge so I would be ready to go again the next day. If I had a cloudy day I would reduce the speed and distance. I now have built a Eco 5.5 catamaran and am planning some trips this year with it. I have put a link below where I was experimenting with tilting the canopy to maximize solar performance.?
For me, I am now a solar electric fanatic.

Phil





On Sunday, March 13, 2022, 05:12:37 a.m. EDT, Gerridae <owly@...> wrote:


??? We are reaching the point where electric power will soon "pencil" at least as auxiliary.?? Weight of the batteries is the killer here, especially where multihulls are concerned with their minimal load capacity.?? Let's say 20kwh of lithium ion batteries are at about 120kg......... a fairly realistic figure.?? 1 hp is about .75 kw.? Lets say you are running 5 hp = 3.75 kw??? 20kwh is 20 kw for one hour.?? That works out to 5.3 hours at 5 hp out of 120kg or 264 lbs.??? That means that to have a steady 5 horsepower output for 10 hours is going to take almost exactly 500 lbs of batteries.?? That's not that bad when one considers engine weight and fuel weight for a gas or diesel engine.?? But it's only 10 hours.?? With sufficient solar power one could get quite a bit of propulsion direct on a clear day.?? Let's say 18w per square foot of solar panel, and that's 208.3 square feet of panel.? That would be a solar array of 20.8' x 10' or 12' x 17.36'... etc.? That's a LOT of solar, and it's NOT charging batteries, just delivering 5 HP to the prop.??

??? It's obvious that at this point we can only use solar electric along with wind realistically.?? It can provide additional propulsion in light winds, propulsion in port, get us through the doldrums perhaps, and perhaps break our bond with fossil fuels.? We can run the galley, etc with battery electric, and we can also generate with regen, or a wind charger.?? And we can run the watermaker......... all depending on conditions.??? It means that you can pull into port, set anchor, and NOT haul fuel, propane, or water when you are voyaging.??? This is exciting stuff if you look at the whole picture.? We can also look at increasing solar panel efficiency, and battery density to the point that this will make more and more sense over time.

??? ??? ??? ??? ??? ??? ??? ??? ??? ??? ??? ??? ??? ??? ??? ??? ??? ??? ??? ??? ??? ??? ??? ??? ??? ??? ??? ??? ??? ??? ??? ??? ??? ??? ??? ??? ??? ??? ??? ??? ??? ??? ??? ??? ??? H.W.


On 3/12/22 1:43 PM, Bernd Kohler wrote:

?

It is surprising how many of my boats are sailing the world, and I know nothing about them.

Here is a solar electric ECO 75 sailing in New Zealand. I found the article and the photos in the Junk Rig Association magazine.

Interesting is his way of living and trying to have a low footprint. I will try to find him so that I can use his article. Here are some important facts.
The boat is built according to plan in12 weeks spread over a year. He added Kevlar on the bottom.
Only four of the 6 solar panels are used to recharge the Lithium batteries. Boat speed with the setup as is today around 5 knots.
Can be about 8 knots with a second e-motor. He is also thinking to use a 20m2 kite for long distances.
I will try to find the owner and get some more information.
 

Hi Jack
I am a bad bookkeeper, as far as I know, the plans were sold by Duckworks.
The guy is close-lipped and is keeping a low profile. I got more questions about
his precise whereabouts but I had also no success.
In the article is no information on what motor he uses.?
How far are you? Ready to go this year

Groeten Bernd
 

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Hi Bernd,

?

There is not a lot of progress as there are many other things which needs to be done.

It will be a miracle if I got the boat in the water this year.

I’m still sanding the outside while making the interior and the electric outboards.

?

Now the weather gets better, I can do more in the same time, as I don’t have to fire the woodstove, and fill it every now and then.

?

How are you, and what keeps you busy these days?

?

Groeten

?

Jack

?

Van: [email protected] [mailto:[email protected]] Namens Bernd Kohler
Verzonden: donderdag 17 maart 2022 1:50
Aan: [email protected]
Onderwerp: Re: [K-Designs-Multihull-Sailboats] ECO 75 solar electric built in NZ

?

Hi Jack
I am a bad bookkeeper, as far as I know, the plans were sold by Duckworks.
The guy is close-lipped and is keeping a low profile. I got more questions about
his precise whereabouts but I had also no success.
In the article is no information on what motor he uses.?
How far are you? Ready to go this year

Groeten Bernd

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