Lagoon 420 hybrid + modern tech

[StuM]

Your 20 Amps per motor for 4 knots is using about 2KW or 2.5 HP.

That sounds reasonable for a 2.5 tonne 26 ft catamaran at that speed in calm conditions.

It works out that 10% of your total weight is motors and batteries
I wonder how that would scale up pushing a 15 tonne Lagoon 420?

[PacificGreen]

Hi Stu,

I have 12 180w panels for a total of 2160 watts of solar array. They are installed in series and then parallel and run up around 79.6 voc with each series group producing 5.48 amps for a theoretical maximum of 32.88 amps.

My motors are old school Ray Electric Outboards. Ray Electric Outboard :: Specifications
The are rated at 4hp but well they do more. For no good reason I've dumped the amps all ahead full and can spool up around 100amps on each motor. Really though talk about wasting power for no good reason other than to test the system. The boat isn't going to go any faster in displacement mode and I can more or less achieve the same results for much less energy hitting my 4 or 5 knots as opposed to 6.7 knots but I've had it at 7.1 knots.

If I did want to run flat out I would use generator assist once my bank dips past 52.5v and have my dc generators produce the 120 amps of power needed to sustain that load.

Not only that but the solar canopy provides shade all day long. I am considering outfitting with a further 4 more panels as I have the room for them. Then I can pretty much guarantee to charge my batteries in a day or two if I really wanted them to be full from sun alone.

The lagoon is a heavy boat already. To help it scale better I'd remove the lightning rod from the top of the boat loose all the deck hardware associated with attaching it to the boat and put the sails into bags on shore. Especially if I were around the equator. Otherwise weight wise it appears to scale great and will only scale better with 40kwh of lithium batteries and 3000w of solar on the roof.

In the grand scheme of things $30000 really when it comes to a boat is not really much money. The biggest concern on the Lagoon is apparently the overly complex management system for the electrical on the boat. I'd loose the AC generator if it has one and go with a dc genset. I'd then invert the power from one of the banks for house use with inverters. For electronics I'd use a converter from 120v to 12v.

[StuM]

Originally Posted by PacificGreen

Hi Stu,

I have 12 180w panels for a total of 2160 watts of solar array. .

Ah, yes. I forgot about that when I did the weights.

So that's:
Motors - 2 x 33kg = 66kg
Panels - 12 x 15kg plus mounting - say 200 kg
Batteries 16 x 13kg = 208kg

So 474 Kg, call it 500 by the time you include all the ancillary electronics etc.

So it's about 20% of your all up weight devoted to your motive power.

(I've just realised that what you are talking about is not a sailing cat, it's actually a solar powered vessel covered in panels - with a cruising speed in calm inland waters of 4 kts. So any comparison to auxiliary power on a cruising sail boat are pretty irrelevant).

[BigBeakie]

Yes Gary I agree, let's get specific. Comments inserted below...

Originally Posted by GaryJones

Hey BigBeakie,

You'd probably find that we are not a million miles away on what we think, just that for me to go electric, I'd probably take the chance and not have the generator.
It is tempting to forego the genset, BUT for extended motoring when it is total cloud cover or for when the range required would be beyond the EP battery bank, then it seems like sooner or later, it will be needed. But I agree, it might have very minimal use, especially when you look at the regeneration capability of good EP systems.

I do think you are being a bit ambitious with your 5-6 knots on solar alone. 4 knots might be feasible in calm waters but you certainly aren't doing 5-6 knots directly into any sea state Moderate and above on solar alone.
No , not overly ambitious at all, these are what is being achieved now. Our boat will be 50 feet and cruising displacement of 13 ton, and these are the figures from the vendors analysis program which have been shown to be spot on with other installations. Specifically we expect to get about 5 knots drawing 3.2kW (our solar capacity) & 7.5 knots at full power from our 16kW EP bank. Don't forget, you'd only motor on solar alone when becalmed, otherwise you'd be sailing! And while sailing, you may elect to top up the battery bank with regeneration for a very, very small speed loss from the feathering prop.

Let's talk specifics, assuming a 45' cat with 3kw solar and 2x 15kw OceanVolt engines and 16x 160Ah lithium batteries.

Are you saying you'd have a 30kw generator to enable indefinite running of the engines?
A smaller generator to top up the batteries with reduced range?
Our generator will be putting 10kW back into the Super B batteries. We will motor at just over 6 knots drawing 10kw from the bank as the genset puts back 10kw, at the most efficient section of the efficiency curve. So we are at zero balance for extended cruising. That's not so bad, is it? There is just no reasonable need for a 30kW genset at all! Why would you want to motor at full power indefinitely????

I just find it helps to talk specifics so we can see where the difference lies.

I think for those who keep insisting that EP is not viable, or feasible, or equivalently as useful as diesels in a meaningful way, that they look at what is being achieved right now. Yes, you cannot motor at full speed for as long as a full tank of diesel lasts because of the energy density, BUT, so what? When does anybody ever do that anyway on a boat that can sail? Now if you have a boat that NEEDS to rely on your engines, well that's your choice to keep filling up the tank and paying for diesel maintenance over the years. But to say that there is not a credible alternative in EP, is just wrong.

[PacificGreen]

The weight for my boat is irrelevant really. The basis of the electrical install is the heart of the boat. It is a for living on and cruising on a daily basis. The fact that it provides motive power is simply a bonus.

I know other people in the marina with the big diesel engines that well honestly self confessed would never dream of starting their diesel engines even to charge batteries. They stay locked to the dock attached to their big extension cords and that is where they sit for most of the year. If they are lucky they get out to the ocean once a year and even then most have to budget their time away.

I know every weight right down to the last pound on my boat and when I say the weight for me is not an issue at this point. For example:
Solar panels 6 lbs each with backing 10 lbs each all 12 for 120lbs. So that is some pretty reliable light weight energy production right there.

Panels 120 lbs
Motors 144 lbs
Batteries 535 lbs
Wiring 200 lbs
Generators 250 lbs

So that is 1250 lbs. But hey lets add in the electric incinerating toilet, the washing machine the induction cooktops the two dehumidifiers, the fridge, the radar, the chartplotters, laptops, the two battery chargers, the two heaters, the tools, the two hot water tanks. Don't forget the food and clothing - it was all in the boat on the travel lift when we got the weight 5400 lbs and then we cheered.

The diesel cruisers still struggle with basic electrical concepts and try and run all their gear on 12v heart interface stuff from the eighties. My boat sailed from England to arrive in Canada many years ago but honestly if you remove the weight of all that sailing gear your much better off. Most of it is not light and when removed the boat is probably 500 to 1000 lbs lighter so that is the comparison. The boat is easier to operate and your still harnessing mother nature but in a more efficient and economical way. If I wanted to harness wind I have that option in the form of a wind generator but I digress.

All I know is that people are genuinely impressed with the boat and not a day went by when people would stop and chat and ask how we did it and what we used. Most are so confused by the options and the fud that they have no idea where to begin. They are locked either into sail rigs or diesel rigs and at great expense and the likely hood of them ever making it off the dry dock or marina is well at times laughable.

We spent 4 months on the hard outfitting. We moved aboard the same day and had power up and running and never looked back. When the marina yard manager of 30 years said it was time for us to go in the water we had to agree with him - even he knew we were ready. More so the big diesel boats we were camped beside honestly didn't ever have a chance - their dreams will die a rusting useless scrap of metal locked in by their poor choices.

So far as motoring is concerned should I choose to run both my generators and apply current to the outboards I could run for as long and hard as I wanted to pushing a cool 50 amps per motor doing five or six knots into the wind or otherwise.

Otherwise for those contemplating small banks being driven by AC generators that could be trouble. Get the biggest lithium bank you can find. Minimum 20 kw/h and then spec your small generator DC feeding two banks. Invert power from there one for house one for propulsion if you like or make one big bank it really doesn't matter with lithium.

[GaryJones]

Originally Posted by BigBeakie

Yes Gary I agree, let's get specific. Comments inserted below...

I think for those who keep insisting that EP is not viable, or feasible, or equivalently as useful as diesels in a meaningful way, that they look at what is being achieved right now. Yes, you cannot motor at full speed for as long as a full tank of diesel lasts because of the energy density, BUT, so what? When does anybody ever do that anyway on a boat that can sail? Now if you have a boat that NEEDS to rely on your engines, well that's your choice to keep filling up the tank and paying for diesel maintenance over the years. But to say that there is not a credible alternative in EP, is just wrong.

As I suspected, we are in pretty close agreement. I just suspect you should prepare for slightly less power from your solar panels over the course of the day and hence budget for slightly lower knots but there's also a good chance I am wrong and you are right.

We also differ slightly in our mix between house bank and generator. I'd have 30kwh of battery and no generator but my plan is probably riskier and has more downsides.

Now all I need is the money, the boat and more sailing...

[PSea]

Glad to see EP users chiming in. Very helpful!

[PacificGreen]

Here is a track albeit of only a 4 hour cruise down and up the Fraser river to Stevenston and back. The trip was 17.60 nm. Highest speed downhill was 5.76 knots (6.7 knots hull speed easily obtainable and 7.1 before) and uphill was between 3.5 and 4 knots against the current. This was to be somewhat expected as the tugs don't even move much faster up river against probably 4 or 5 knot currents perhaps even 6. The track was done in April. You can import into google earth or if you have opencpn you can import the track through the route manager.

So the Lagoon 420 hybrid plus some 1000ah lithium batteries, 700ah lithium batteries would fare quite well. I've seen a couple super B batteries and I'm not impressed really. What is inside? Can you view the individual cells that comprise the unit. No you can not. For what matters 160 ah is not enough for any reasonable amount of energy storage. Bank will deplete quickly. Minimum 400ah.

http://www.ev-power.eu/LTO-technolog...2-4V-30AH.html

This appears to be the future of Lithium batteries. I"m waiting for them to make larger format prismatic cells out of them.

[Hyprdrv]

Electric drive for Lagoon catamarans

First Electric Lagoon Crosses Atlantic

I own 1 of the 3 410's built.

Steve in Solomons
Lagoon 410 SE

[PSea]

12hp electric motor replacing a 28hp or 40hp diesel saildrive.....

"Fuel consumption, while motoring with the generator, was 1.3 to 1.4 gallons an hour. Scott points out that this consumption rate is less than with the Lagoon 410 s standard twin 40hp diesel installation. "Each 12 hp motor is equivalent to a 40 hp diesel," he says, "and you'd burn about 0.8 to 1.0 gallons an hour in each diesel engine to reach the same speed.""



Thanks for the links.

[visscher]

Originally Posted by Stumble

It would be marginally better, but not substantially so. The fundamental problem is that there isn't enough power in sunlight for propulsion, and batteries aren't energy dense enough to compete with liquid fuels.

Wow things change quick! This statement wasn't even true for a full year. Nowdays there is enough power in sunlight to power a gigafactory, it must be getting brighter!

[44'cruisingcat]

Originally Posted by visscher

Wow things change quick! This statement wasn't even true for a full year. Nowdays there is enough power in sunlight to power a gigafactory, it must be getting brighter!

There's enough power in sunlight to power an entire solar system. If you could collect enough it could power anything. It's the collecting that's the problem.

[cwjohm]

Yes, it is really good if you want your gigafactory to operate from 10am - 2pm only.

[visscher]

Originally Posted by cwjohm

Yes, it is really good if you want your gigafactory to operate from 10am - 2pm only.

Unless someone brilliant came up with 14kwh batteries that weighed 200lbs each. All you need then is enough batteries to power motors for 24 hrs and enough solar panels to fill those batteries between 10-3. Every year make the solar panels able to capture energy more efficiently while making batteries lighter and at some point the whole burning fossil fuels thing becomes foolish.

So you know the what the efficiency of solar panels being produced today is?



How many 2170 cells do you need now to run a boat for a day? Does it weigh more than 400 lbs?




I applaud the fact that you know the sun is up between 10-2 each day. But what my 3 year old doesn't know is how efficient we are today at storing and using that energy without loss in converting to a/c etc.

[cwjohm]

I know exactly what the efficiency of solar panels is today.

I have looked at the powerwall 2 and solar extensively for the purposes of going off grid at my rural property and for the boat.

The realities of using solar power without base load means it is still a long way distant.

I would suggest your 3 year old does not as yet drink the cool aid that Musk and others are offering.