How to calculate a Solar system for a Trimaran ?

[Skip JayR]

Hi, folks !

... I am new here. Actually I am in my own plannings for "living on a boat" from 2016 on. I am a big fan of multihulls and the boat shall become a Trimaran, for living + working.

As most of you know Trimaran only can deliver their potentials to the owner if they are built light weighted... and kept leight weighted (no heavy loads).

So I am researching the sales market internationally to find an adequate boat/trimaran.
It shall be in the range of 38/39 foot... eventually up to 40-50 foot (so far it is a boat in the prize range of my total budget). Something like this...

39 footer...


Mostly all the boats I have looked out have Solar, regularly 1 or 2 tiny solar panels on the amas (outriggers), e.g. this 40 Footer Tri


... rarely on the sprayhood roof (fixed on a hardtop frame) or astern on a stand, e.g. this 50 Footer has and rarely seen on trimarans.


So its clear: I have to get a feeling for the dimensions of an expanded solar system newly... as first step to get an idea for the budget (roughly pre-calculated) as the existing solar sytems wont have the dimensions I will need.

Does exist a kind of Excel Sheet to calculate the size of batteries + solar system, eventually in combination with Wind Energy or (Hdryo-Energy propellor) ?

As I (have to) work on board as cultural journalist roughly 50 % of the monthly time, mainly I will use different laptops/tablet pcs (regularly 3), screens (4x), file server with backup sytem (4x hard discs), 1x mini printer and WIFI/LTE system (router) for Internet access front coast... and some few recording equipment for a mobile radio recording studio.

The regular work process is to run at least 2-3 laptops parallel (10 hours), plus file server with backup system (24 hoursx7d)... temporarily the studio equipment (all mounted in a 19' rack) will be used for 3-4 hours within one recording session (e.g. mixer panel, external midi sound cards, active microphone, compressor/gate for sound signal processing, loudspeakers).

Beside this working station the boat shall get an infra structure to be independently, e.g. hot/cold water pump sytem (at least deckshow), hot water shall come from propan/butan gas terme, so no big hotwater tank... and for fresh water - as Trimarans only have small tanks - is required water maker... ...and for all year cruising it needs a heating system (probably propan/butan gas).

Cooking can be done with solar stoven, seperately.

The boat shall be equipped for auto-piloting (probably Windfane is not suitable for a a speedy Tri so it needs 2 electric autopilots, one in reserves), navi electronics (following SOLAS standard) e.g. Copass, GPS, radar, chart plotter and all other electronic devices (sonar, wind, speed log, vhs with AIS)... plus routing planning using one of the racing programmes and electronic weather maps on a laptop.

The light system (position lights, deck light, cabin lights) shall become LED.

If possible I try to avoid a diesel generator for charging the batteries as a Trimaran only has very small gasoline tanks. Tris only have small diesel engines, some even only an outborder.

Lets see if it is possible to realize my dream. If you have a kind of excel sheet or another tool for pre-calculating the system I'd be very thankfully.

Tks in advance for giving attention and your advices.

Happy & Safe Sailing !

(P.S.: If you are interested in Trimarans, I am documenting my search for the boat on a small blog here: https://trienthusiasts.wordpress.com )

[Roy M]

Welcome aboard! Check out the Searunner tri thread on CF for like-minded folks. I , too, am about to make the plunge on a solar system for my own boat. I have a forty-foot Searunner that will be leaving this coming summer for a series of cruises, after thirty-something years of more limited cruising, then overhauling and renovating. My battery bank is composed of four L-16 6-volt batteries in series-parallel, yielding 740 amp hours of storage. I am planning, at present on using Sunpower panels with several MPPT converters. One of our our CF denizens, Socaldmax, has been supplying excellent advice.

[Skip JayR]

Originally Posted by Roy M

Welcome aboard! Check out the Searunner tri thread on CF for like-minded folks. I , too, am about to make the plunge on a solar system for my own boat. I have a forty-foot Searunner that will be leaving this coming summer for a series of cruises, after thirty-something years of more limited cruising, then overhauling and renovating. My battery bank is composed of four L-16 6-volt batteries in series-parallel, yielding 740 amp hours of storage. I am planning, at present on using Sunpower panels with several MPPT converters. One of our our CF denizens, Socaldmax, has been supplying excellent advice.

Tks, Roy ! Sounds great... So I will look over to the Searunner thread and ask there for a tool to pre-calculate the dimensions.

... and good luck for your own project ! Such a "big Tri" should go out onto high seas for long distance sailing to be in the right element ;-)

[deckofficer]

On a tri (as with any multihull) weight is the enemy. With your work station and hours of operation, you will need to both harvest a lot of energy and be able to store a lot. IMHO, this removes lead acid batteries from your equation. LiFePO4 cells are about your only battery option. Framed solar panels are not only heavy but that weight is high thus raising CG of your tri. There are flexible and efficient panels that tip the scales at 4 lbs for 100 watts vs 40 lb for a framed 100 watt panel.

[Pete7]

I can understand you desire for solar, but running all that IT is probably going to require a honda 20i generator whilst you are working. Although there is a running cost it would weight alot less than a bank of batteries and solar panels.

Pete

[CarstenWL]

vs 40 lb for a framed 100 watt panel

The SunPower X21-345W (345 Watt Solar Panel) is around 40lb ... 40lb for a 100W module sounds 'a bit heavy' ...

Carsten

[deckofficer]

I've seen a home brew file server 9 TB that was designed for low power consumption at 40 watts. 24 hours per day would be 960 whr per day. 2~3 laptops @ 10 hours around 600 whr per day. Other hotel loads could easily match the above loads (lights, TV, freezer, nav station, galley loads, etc), so all together something north of 3200 whr per day. A flexible 100 watt solar panel averaging 5 hours per day, it would require at least 6 panels.

[Skip JayR]

Originally Posted by deckofficer

I've seen a home brew file server 9 TB that was designed for low power consumption at 40 watts. 24 hours per day would be 960 whr per day. 2~3 laptops @ 10 hours around 600 whr per day. Other hotel loads could easily match the above loads (lights, TV, freezer, nav station, galley loads, etc), so all together something north of 3200 whr per day. A flexible 100 watt solar panel averaging 5 hours per day, it would require at least 6 panels.

So quickly it goes... many tks, Deckofficer for such a simple pre-calculation.

You mean something like this :-)


I suppose flexible Solbian are "state of the art" for Trimarans, isnt ? :-)


The 40 ft. Trimaran Spirit (Formula 40) which was refitted during 2014/2015 and since July back in the water as cruiser got such Solbian panels with totally 548 watts plus Genasun regulator and LiFePO4 lithium batteries from EV power. Pictures here: https://www.facebook.com/SolbianEA/p...49926565063203

Solbian's most efficient panels (>19%) of the SX Series are available with 156W at two different dimensions (A: 1523x683x2 mm / B: 1046x996x2 mm ) and have a weight of 2.4 kg each.




Should I think and proof the prices into that direction of product solutoin ?

[Skip JayR]

Originally Posted by Pete7

I can understand you desire for solar, but running all that IT is probably going to require a honda 20i generator whilst you are working. Although there is a running cost it would weight alot less than a bank of batteries and solar panels.

Pete, yes I have thought about, necessarily.

A fixed installation in a "used trimaran" might become difficult. As there is lack of space. So yes, a portable generator probably would be the alternative, if not possible with solar. - Or at least as a kind of "emergency case security in reserves solution".

Personally I dont really like the idea (thinking about other issues, e.g. oil filter, cleaning air filter, replacing spark plug and installing/cleaning extra tank).

For the high peak of studio production which has one session of round 4 hours duration roughly... with minimum 4 x 4 units during 2 weeks irregularly... so at all 16 hours high peak, 32 hours in max. per months (as worst case if the job is heavy work overloaded)...

Such a generator has a very small tank capacity of 2.1 liters (see link to data sheet) to operate for rated 3.5 hours with max. 1000 W. While the recording sessions are up to 4 hours I cant calculate to interrupt this work process for filling the tank.

I'd need 10 fillings = 21 liters over one month. To become independently over 3 months it would need an extra tank of 60 liters roughly.... where the generator is connected to and for security, this tank would need an own filter system, too.

I feel very uncomfortable to depend too heavily on gasoline transportation and extra tanks for it, beside all the upper named maintenance work.

Data sheet: http://www.honda.co.uk/industrial/pr...fications.html

[Skip JayR]

Originally Posted by deckofficer

I've seen a home brew file server 9 TB that was designed for low power consumption at 40 watts. 24 hours per day would be 960 whr per day. 2~3 laptops @ 10 hours around 600 whr per day. Other hotel loads could easily match the above loads (lights, TV, freezer, nav station, galley loads, etc), so all together something north of 3200 whr per day. A flexible 100 watt solar panel averaging 5 hours per day, it would require at least 6 panels.

Dimenion of the battery bank...

If I take deckofficer's pre-calculation as first estimated for a regular consumtion of 3,2 kW per day with a 12 voltage how to calculate the dimension of the battery bank ?

I know about the two formulas...

1. mAh to Wh: (mAh * V)/ 1000 = Wh and
2. Wh to mAh: (Wh / V) * 1000 = mAh vice-versa

Is it right way to calculate the Ampere hours for the battery banks ?

As an example lets say with daily 3.2 kW = 3,200 W / 12 V = 266.67 Ah.

If installing a battery like the LiFEPO4 has 20 Ah/12V... and the maximum discharging is not overstepping 50%, I'd need 2x 266.67 Ah = 533.33 Ah = 26 batteries in total, each 4.47 kg = total 120 kgs weight.

As total dimentions (each battery has 181x77x167 mm) it would become a block size of roughly 1.04 meter (l) x 0.37 meters (w) at a height of 16.7 cm.



Is this correct ? (Rec.: I am not an engineer.. just did some basic physics in school. So I appologize for my "newbee knowledge".)

[deckofficer]

First off while the Solbian is the top end, so is the price. Renogy is a much better deal for something really close to the same product. Around $230 USD per 100 watt panel. As to the LiFePO4 cells, I don't understand your choice of a 20 ahr cell. It is much better to size the cells for a single series string instead of series/parallel. For your rather robust needs I would go with at least 400 ahr cells. With the low Peukert effect and deeper DOD of these cells over lead acid, you would get about the same usable ahr as going with 800 ahr of lead.

Keep your math simple and leave all calculations as watts and watt/hour. A 400 A cell has 1300 whr (400 A X 3.25 volts). It will take 4 cells to make a 13 volt bank with 5200 whr capacity X 0.8 (DOD) for 4160 whr of usable storage. This should handle your needs without breaking the bank.

[deckofficer]

FYI

http://www.amazon.com/Renogy-Watts-V.../dp/B00IK19VF6

400Ah, 2-5C, 3V LiFePo4 Lithium Prismatic EV Battery

At 13 kg X 4 = 52 kg

[Skip JayR]

Originally Posted by deckofficer

First off while the Solbian is the top end, so is the price. Renogy is a much better deal for something really close to the same product. Around $230 USD per 100 watt panel.

Tks... yeah... would need a sponsorship by Solbian ! :-) Always good to know alternatives. :-)

Originally Posted by deckofficer

As to the LiFePO4 cells, I don't understand your choice of a 20 ahr cell. It is much better to size the cells for a single series string instead of series/parallel. For your rather robust needs I would go with at least 400 ahr cells. With the low Peukert effect and deeper DOD of these cells over lead acid, you would get about the same usable ahr as going with 800 ahr of lead.

Ah... because the online shop I went to only offered 20Ah... haha. Already wondered by myself about that tiny "size".

Okeys.... will check it out.

http://www.youtube.com/watch?v=oJ8AfJsOhsM

It is said: The difference between SE and CA series batteries is the SE has higher energy density, and the CA has internal heat separators and 2-3% higher series/pack capacity.

Is it a "heat" problem to take higher energy density (SE) ? Do these batteries need kind of "extra cooling" ? Sounds like for a newbee the CA is the better choise for more safetyness as I dont have interests the batteries catch fire.

And it seems of benefit the smaller weight, just 13.5.-13.6 kg for one 400Ah at the dimensions of 450 (l) x 71 (w) x 287 mm (h) or 461 x 65 x 285 mm.

Is it good to look from traders who build such blocks for electric cars ? - E.g. here as akternative to what you linked to (from electric car parts company) or here (Balqon Electro Vehicles) at a prize of 490 - 525 US dollars.

Originally Posted by deckofficer

Keep your math simple and leave all calculations as watts and watt/hour. A 400 A cell has 1300 whr (400 A X 3.25 volts). It will take 4 cells to make a 13 volt bank with 5200 whr capacity X 0.8 (DOD) for 4160 whr of usable storage. This should handle your needs without breaking the bank.

Understand... tks.

Is there a ready "excel sheet" (or even software) to download I can list all the "consumers" so at the end I get a more precisely result ? :-)

[Skip JayR]

Originally Posted by deckofficer

FYI
Amazon.com: Renogy 100 Watts 12 Volts Lightweight Monocrystalline Solar Panel: Patio, Lawn & Garden

The prize difference... e.g. 4x Solbian SX Flexible Marine Solar Panels (type: SX 156 L = 156W/12V) = roughly 5,600 Euros (~6,000 US dollars) while 6x Renogy 100W = ~1,400 US dollars.

How comes this extreme prize difference ? Tremendously...
As bundle Renogy even has 800 Watt for only 1,600 US dollars.

I just checked about services in Europe. It seems the sales structure of this US product does not exist in EU for "marine/RV" solutions. They say on the website, that the "Farm system" is certified in Switzerland.

[blackswan555]

There are spreadsheets out there but I find it easier to just do it on paper, ( ok I am old lol)
Take a look at every appliance label, note volts & amps, X volts by amp's to give you VA, VA X time appliance will be used,

eg, A standard old 1 bar (resistive,1kw) electric fire would be 4.34 amps x 230v = 1000va, have it on for 2 hr's, total consumption, 2kva per day,

Presuming a 12v FLA battery bank, 2kva/12v, 166.6 AH per day,
Observing the 50% DOD rule 333.3 ah total capacity,
Simple a ? Ok I throw a spanner in the works

Why am I talking in VA and not Watts ? Because inverters, batteries & generators work in VA not Watts,
Power factor is used to calculate W from VA in AC loads, If it is an inductive load (not a heating element basically) it will have a PF, Some of the worst offenders are "low energy" bulbs with a PF as low a 0.5, Meaning that when the label say's "11W" in our money it will actually be using about 20VA,
Laptop & computer power supplies are not much better But then they are even more difficult to estimate as their load is variable on workload of machine, (My laptop will vary between 9 & 45VA) The best way to calculate these is with a "Kill a watt" or similar type watt meter, (beware most of them are "in" watts, recalculate to VA)
When you have there numbers you should be able to get an idea of what size battery bank you need,

Tim