1.2-1.6 KW solar?

[LeoKa]

I really want to have a solar charging system, but most of the kits I find on the web are designed for sailboats. They go up to 300W, but not more. On my trawler, I have plenty of space on the top, so I could easily mount 4 large panels. LG and others are selling 400+W panels now, although, not cheap. The sun is scares in the PNW, so I want to oversize it for that little light we get here during winter months.
Has anyone built a large capacity solar system on their boat? Or, do you know anyone? Perhaps, a company, which can design one like this for marine environment? I have seen many land based systems with huge capacity, but not for boats.

 

[Insequent]

My first system was 7 x 260W panels, installed in Port Townsend by the CoOp guys. It is not that complicated to do. The only issue I had was shading of some of the panels in some boat orientations.

So I relocated a number of items, including my KVH dome, and increased capacity slightly by installing 6 x 345W panels in a way that there is a lot less shading, although I still get some at times.

Its best to install the panels in parallel to minimise shading effects. With large panels you will have relatively high panel voltage, which is an advantage in that voltage drop on the wiring from panel to controller is less of a problem. But still use wire size bigger than calcs say is necessary.

With a number of panels you can easily exceed the output current capacity of the solar controller if you are not careful. One solution is to have a higher voltage house bank, say 24V instead of 12V, but if you don't have 24V on board already then your other option is to add a second controller. There can be some tricks to making the two (or more) controllers work together, depends on brand.

My system is 2070W, 12V house bank and 2 xOutback FlexMax 80 solar controllers (with a Mate 3). I have had the panels putting a total of 160A into the house bank. It works well.

 

[what_barnacles]

just an fyi...


you can get micro inverters for each panel that pretty much eliminates shading issues and simplifies the system overall.


https://www.wholesalesolar.com/brands/enphase-energy

 

[Insequent]

just an fyi...


you can get micro inverters for each panel that pretty much eliminates shading issues and simplifies the system overall.


https://www.wholesalesolar.com/brands/enphase-energy

No. Those are for grid-tie systems. You don't want to invert each panel's output up to a high AC voltage for an off-grid or boat solar system.

You want a controller (or many, perhaps even one per panel although it is not necessary) to charge a low voltage DC house bank. And remove, as much as possible, whatever is causing the shade.

 

[DavidM]

Inverters whether micro or not are used to connect to the grid. I think you are talking about individual solar controllers which will do what you are saying but will be expensive.

The design of solar panel systems isn't difficult and I wrote two articles on this subject that are in the Library section. Click on Library in the upper right corner of this screen.

If you use the big 400 watt panels then one controller for each panel makes sense. It will take at least a 30 amp MPPT controller for each panel and wire them to the controller with #10 gauge MC4 cables. Then use #8 wire or better from the controller to the house battery bank.

You will need a big battery bank to absorb 1,600 watts of power though, at east 600 AHs.

Dhays had an extensive thread on installing a solar panel system for his boat.

David

 

[LeoKa]

My system is 2070W, 12V house bank and 2 xOutback FlexMax 80 solar controllers (with a Mate 3). I have had the panels putting a total of 160A into the house bank. It works well.

Does this cover all your needs, or you still need to run your Gen.?

I have two banks, 12V, total of 840 AHR (4 Trojans 6V each bank).

 

[LeoKa]

You will need a big battery bank to absorb 1,600 watts of power though, at east 600 AHs.
Dhays had an extensive thread on installing a solar panel system for his boat.
David

Thanks David. I will read your article in the Library and check out Dhays' as well.

My two banks are 420 AH each, so I have total of 840 AH.

I like the idea to have at least 2 controllers for the panels.

 

[kchace]

I like the idea to have at least 2 controllers for the panels.

My house bank is also split in 2 and I agree that a controller for each bank is an asset. Using the MC4 connectors, splitters and cables it's not difficult at all to design and set up a solar array. Just use good quality components and be careful to size wire runs appropriately. As someone else said, solar is the gift that keeps on giving.

Ken

 

[LeoKa]

Can any of you list a complete set, part by part? I mean, not just the panels, but the controllers, wiring, connections, etc.
I am not trying to copy it. I just want to see, what do I need to buy for a complete system.

 

[DavidM]

OK, here goes, all from Wholesalesolar.com and Amazon:

Solar panel, most bang for the buck- https://www.wholesalesolar.com/1977...ronergy-chsm6612p-325-silver-poly-solar-panel

Controller- https://www.wholesalesolar.com/3930...-kid-30a-mppt-mnkid-b-black-charge-controller

MC4 Cables- https://www.wholesalesolar.com/9991...olar-dual-mc4-10-awg-50-cable-1-male-1-female

Just an example. Amazon has MC4 cables in various lengths. Or buy marine cable and hook up MC4 connectors to panel end and use spade terminals at the controller end.

MC4 Cable pigtail. Use to make last connection to controller- https://www.amazon.com/Extension-Co...pID=41oTzk3ucLL&preST=_SX300_QL70_&dpSrc=srch

Or just cut off the MC4 connector at the controller end, crimp on a spade connector and hook up to the controller.

Solar panel mounting brackets- https://www.amazon.com/XOOL-Solar-M...&keywords=solar+panel+mounting+brackets&psc=1

Fuse holder. Mount within seven inches (per ABYC) from battery terminal- https://www.amazon.com/InstallGear-...id=1537724142&sr=8-9&keywords=anl+fuse+holder

8 gauge tinned wire between controller and fuse- https://www.amazon.com/BNTECHGO-Sil...537724355&sr=8-2&keywords=8+gauge+tinned+wire

8 gauge is ok for a single panel if the fuse is 80A. For four panels/controllers all connected to the fuse then use #4 wire and the 150A fuse shown.

Misc glue, spade crimps, nuts and bolts

Double, triple or quadruple each of the above in parallel (except for fuse) for more capacity.

Please send consulting fee to .......

David

 

[Insequent]

Does this cover all your needs, or you still need to run your Gen.?

I have two banks, 12V, total of 840 AHR (4 Trojans 6V each bank).

Simple enough question, but not a simple answer!

Firstly, the only gen I have now is a Honda. In winter (Jun-Jul for me) I will often run it, but I have not run it in the last two months. Better insolation post-winter, and in part because I've been at lower latitude as well. Also, i have been moving a little each day for a lot of the time and each engine has a 200A alternator.

My bank is 1284 Ah. It is a fairly good match to my solar capacity. I do use a lot of power compared to many: overnight consumption is invariably more than 400 Ah. Reefer and freezer are big users, but I have a lot of other small loads. Many of these could be avoided eg turn the KVH sat dome, TV/set-top box off. But I usually don't bother.

Were I doing it all again I would have a gen, and aircon.

 

[LeoKa]

OK, here goes, all from Wholesalesolar.com and Amazon:
Please send consulting fee to .......
David

What a great list, thanks David!

How many controllers do you recommend for 2+2 panels, 350W/panel?
I want 2 panels charging bank1, and another charging bank2.
I have 4 Trojans combined 420 AH/12V on each bank.

 

[Simi 60]

Maybe look at your inverter charger.
Ours obviously charges the main bank but it also has a port to trickle charge the starts.

 

[LeoKa]

Maybe look at your inverter charger.
Ours obviously charges the main bank but it also has a port to trickle charge the starts.

I am not sure what do you mean?
My inverter is a 2700W MagnumSine and I can separate the 2 cranking batteries from the banks.
I want to charge the batteries directly from the controllers.

 

[Simi 60]

My bank is 1284 Ah. It is a fairly good match to my solar capacity. I do use a lot of power compared to many: overnight consumption is invariably more than 400 Ah. Reefer and freezer are big users, but I have a lot of other small loads. Many of these could be avoided eg turn the KVH sat dome, TV/set-top box off. But I usually don't bother.

Is that right or am I wrong?

We have 12v 220 x 8 batts linked as 880ah @ 24v and use about 150ah 5pm to 6am.
Pretty sure we run more refrigeration than you with 800 litres (28 cf) across three 240v fridge/freezers.

Perhaps its to do with the 12v 24v thing as I am sure we don't get anything like 160a smashing in from our 2250w of panels but we do see 80a

.

My system is 2070W, 12V house bank and 2 xOutback FlexMax 80 solar controllers (with a Mate 3). I have had the panels putting a total of 160A into the house bank. It works well.

 

[Simi 60]

I am not sure what do you mean?
My inverter is a 2700W MagnumSine and I can separate the 2 cranking batteries from the banks.
I want to charge the batteries directly from the controllers.

But the cranking batteries are charged by the alternator while engine is running so should only need trickle charging when its not.

Our inverter charger (Victron 5000/100) has a 4 amp outlet for that purpose


Add: I get it now, you don't have a dedicated charger as such?

 

[DavidM]

What a great list, thanks David!

How many controllers do you recommend for 2+2 panels, 350W/panel?
I want 2 panels charging bank1, and another charging bank2.
I have 4 Trojans combined 420 AH/12V on each bank.

Well, it is generally best to have one single large bank rather than two that you alternate useage. But, skipping that for now:


That list was put together to use the great cost per watt of the 325 watt Astroenergy panel with the reasonable cost MidNight 30A controller. The two go together nicely. So you just double the list for one bank and double the list for the second one. Use one controller per panel, which separates shading problems.

That isn't the absolute cheapest way for your situation, but close. You could use two panels hooked up in series or parallel to a 60 A controller. Outback makes a 60A controller for $470, so you save $180 vs two 30A Midnight controllers at $325 each. It has plenty high Voc spec so you could wire your two panels in series and save a bit of wiring, but you lose shade resistance. Wiring them in parallel would also work with that controller and they work independently of shading.


I just checked shipping cost for 4 panels from Wholesalesolar's facility in California to my address in Connecticut- $300. Not cheap because they have to be shipped motor freight. That is why it is often better to use 100 watt panels for small systems because they ship free, at least with Amazon Prime.


David

 

[dhays]

I am not sure what do you mean?
My inverter is a 2700W MagnumSine and I can separate the 2 cranking batteries from the banks.
I want to charge the batteries directly from the controllers.

Am I correct that you are running two separate banks? If so, you may want to consider combining them into one larger bank. It would make the charging simpler and a large bank is more efficient than 2 smaller banks.

 

[LeoKa]

I just checked shipping cost for 4 panels from Wholesalesolar's facility in California to my address in Connecticut- $300.
David

I have this store here locally. They have a nice list what you can buy there:

https://www.platt.com/platt-electri...ionID=16&GroupID=204&CatID=863&SubCatID=11003

 

[dhays]

I have this store here locally. They have a nice list what you can buy there:

https://www.platt.com/platt-electri...ionID=16&GroupID=204&CatID=863&SubCatID=11003

I bought a bunch of the stuff that I used for my Solar project from Platt. Their prices were competitive and I didn't have to pay for shipping. I was able to go to their local store and pick them up.


For charge controllers etc... don't forget to check with Compass Marine.

 

[LeoKa]

OK,
David

Based on your list, here is my collection. Let me know what do you think?



Panels/4x
https://www.wholesalesolar.com/1922...rld-swa-295-plus-black-frame-mono-solar-panel
or
https://www.wholesalesolar.com/1524647/lg/solar-panels/lg-neon2-lg-335n1c-a5-black-mono-solar-panel

Controllers/2x
https://www.wholesalesolar.com/3930...marine-mppt-black-mnkid-m-b-charge-controller

and the rest of your list:

MC4 Cable pigtail. Use to make last connection to controller- https://www.amazon.com/Extension-Con...70_&dpSrc=srch

Solar panel mounting brackets- https://www.amazon.com/XOOL-Solar-Mo...brackets&psc=1

Fuse holder. Mount within seven inches (per ABYC) from battery terminal- https://www.amazon.com/InstallGear-G...nl+fuse+holder

8 gauge tinned wire between controller and fuse- https://www.amazon.com/BNTECHGO-Sili...ge+tinned+wire

8 gauge is ok for a single panel if the fuse is 80A. For four panels/controllers all connected to the fuse then use #4 wire and the 150A fuse shown.

Misc glue, spade crimps, nuts and bolts

Double, triple or quadruple each of the above in parallel (except for fuse) for more capacity.

 

[DavidM]

If you have four 300+ watt panels, you will need four of the Midnight controllers as their DC output spec is 30 A.


That second panel is pretty expensive per watt. The first one is ok at a little less than $1 per watt, but much more expensive than the one I recommended in my original post at 70 cents per watt. Why didn't you pick that one?



David

 

[BruceK]

Checked Ebay for panel prices? And ancillaries? I was astounded when checking recently on Australian Ebay. Way less than 8 years ago when I fitted my little system. True, panels come from China, and true, they may cost you a lot more with your new tariffs on Chinese goods, but worth a look. Quality seems a non issue. I think the vast majority of panels on the myriad of house roofs here are from China.

 

[LeoKa]

If you have four 300+ watt panels, you will need four of the Midnight controllers as their DC output spec is 30 A.


That second panel is pretty expensive per watt. The first one is ok at a little less than $1 per watt, but much more expensive than the one I recommended in my original post at 70 cents per watt. Why didn't you pick that one?



David

I looked at the higher Amp output and long warranty.
I did not want Chinese made either.

I will get 4 controllers. Thanks.

 

[C lectric]

I'm going to toss this into the fray.

https://www.zampsolar.com/


They build really for the RV market of which we are/were part. Found them at Quartzsite last winter and bought one of the portable kits for use on the boat.

Worked well for us this summer. Now that I have it I am looking to expand it.

It is a nice little kit but I'll let you folk scout the site.

 

[kokopelliTim]

I am following this and the other threads on solar power so diligently.

I am looking to soon install solar so I can be more independent.

I feel so ignorant and almost stupid as I look into this. But I am determined as I seek to know the systems of my vessel and install as much as possible.

So I have a couple of questions:

1. Would I need special or different batteries? What batteries are needed for the best results? How many batteries are needed?

2. Realistically, how much does such a system from the above lists cost? Cost for materials and cost for someone to install?

3. So I need an invertor to convert the solar to DC and convert from DC to AC?

I apologize if my questions are simplistic; but that is where I am right now as I begin the process.

Thanks.

Tim

 

[DavidM]

Tim:

I would first read the articles in the Library on this forum, some of which I wrote, on solar panel systems. They will help you with sizing your battery bank and the panel wattage required to do what you want to do. Specific answers to your questions:

1. Flooded cell GC batteries or AGMs are best for house use. GCs cost about $1 per AH and AGMs 2-3 times more.

2. Basic materials for a several hundred watt system cost about $2.50 per watt. I can only guess at professional installation costs, maybe $1.00 per watt or more.

3. I think you are conflating solar charge controllers with inverters. The former are needed to convert and control the power from the solar panels. An inverter is used to take battery DC power and convert it to 120V AC.


You only need an inverter if you plan to power AC loads such as a microwave from your house bank. Medium power modified square wave ones start at about $400 and go up to $1,000 and above for a high power, sine wave inverter/chargers.

David

 

[kokopelliTim]

Thank you David.

Your articles are truly full of information and specifics.
Tim

 

[dhays]

I feel so ignorant and almost stupid as I look into this. But I am determined as I seek to know the systems of my vessel and install as much as possible.

Tim, I know yow you feel. Normally, when faced with a topic that I know nothing about, I can usually get a basic understanding of it relatively quickly with just a little investigation. That was NOT my experience with solar. For some reason, it was really hard for me to wrap my head around it.

Fortunately, the TF community and the resources here were eventually able make the basics a little clearer. David’s article is really helpful in that regard.

It will take you a lot less time to understand the issues around solar than it did me.

 

[mdstrum]

WE have had our system two large panels, total 470 watt, that connection to a BlueSKy charge controller (it also has an AUX output so when house bank is full it switch over and puts the solar to our starting bank and trickle charges...they have great remote as well so you always know what your system is doing.

Blue Sky Energy Inc. | Solar Boost 3024(D)iL

we also put in 2 shunts so we can see what solar into putting into houseware bank and the our magnum inverter/charger tracks what solar is adding and what comes in from the charger (via shore or gen set) so great monitor for overal battery bank status/health.

One the one thing no has mentioned about was to put in some disconnects. Remember when ever you have sun those panel are making power, so we put in two one up close to the panels and at before charge controller, these are simple breaker from blue seas to break the circuit manual and to protect it. This allows for servicing system and batteries with all inputs disabled....learn this one the hard way