Sailboat application

tidetim

New guy to panels. Here is my situation...just purchased 3 Kyocera 135 watt panels with Blue Sky 3024iL controller for my 40' sailboat. Panels will be mounted on a new arch I'm having installed on my boat. Electricity, even DC, is not my strong point. My basic questions follow:
1. Panels/controller will be charging a dual bank of 12v AGM batteries (approx. 380 amps total). Plan to monitor charging with already installed Link 40. Need some help with wiring; size, controller set-up, etc.
2. No installation instructions provided with panels. How do I connect all three in series and then to the charge controller?
Any assistance would be most appreciated.

Tim
S/V Magic
S. Chesapeake Bay

Cariboocoot

Re: Sailboat application

Welcome to the forum.

Let's get right to the problems, shall we?
First problem: the Blue Sky 3025il has a maximum input Voltage of 57. The Kyocera's Voc is 22.1. You can't put three in series on that controller, as the Voc of the array would be 66.3 - well over the Blue Sky's maximum.

The panels themselves will either be the ones with the junction box http://www.solar-electric.com/kykc130wasop.html or the ones with the MC4 connectors http://www.solar-electric.com/kyso130wa12v.html. The junction box wiring is straight forward: (+) to (+) and (-) to (-) for parallel connections (adds Amps, Voltage remains the same) or (+) to (-) for series connections (adds Voltage, Amps remains the same). The MC4 connectors are polarized, so series connections are "plug-n-play". Parallel connections will require some type of junction box. Usually you buy MC4 extension cables, cut them in half, and splice the appropriate wire ends together.

But you can't run three panels in parallel without fuse protection on each one. This would be the way to go with the equipment you've listed. You probably do not need the MPPT controller under the circumstances (405 Watts of "12 Volt" panel, "12 Volt" system). But you've already bought it.

I mention this because how you wire it makes a difference to what you wire it with. Basic rule: Watts = Volts * Amps. More Amps, bigger wire size. Longer wire runs want more Voltage to reduce loss.

The very useful Voltage drop calculator: www.solar-guppy.com/forum/download/voltage_drop_calculator.zip

tidetim

Re: Sailboat application

OK, now I'm even more confused. The 3024iL is what Az Wind and Sun recommended for my 3 panels. Did some checking and you are right about the PV input voltage of 57Vdc max on the 3024iL. But what I got from Kocera was 17.7Vmpp and max current of 7.63amps. If I set them in series (here's where I get to demonstrate my ignorance!), doesn't the voltage remain the same but output amps multiplies by the number of panels? In my example, 7.63 amps x 3 panels gives me a bit over 22 amps maximum output. if, as you say the 3024 is the wrong controller for me, then I have an issue with the Az Wind and Sun and will have to deal with them.
Got a zillion other questions, but I'd like to resolve this first.

Tim

Cariboocoot

Re: Sailboat application

tidetim wrote: »

If I set them in series (here's where I get to demonstrate my ignorance!), doesn't the voltage remain the same but output amps multiplies by the number of panels?

You've got that backwards. Lots of people do.

Series connection: (-) PANEL (+) ---- (-) PANEL (+) ---- (-) PANEL (+)
Voltage goes up, current (Amperage) remains the same.

Parallel connection:
(-) PANEL (+)
(-) PANEL (+)
(-) PANEL (+)
{All (-) connected, all (+) connected}
Voltage remains the same, current (Amperage) goes up.

The really confusing part is that panels have three Voltages:
Nominal Voltage (as in the Kyocera 135 is a "12 Volt" panel).
Voltage at Maximum Power (Vmp) where the peak output is (usually 17.5 Volts on a "12 Volt" panel).
Voltage Open Circuit (Voc) which is the maximum output Voltage without a load on (22.1 Volts on these panels). That's the one that causes trouble for low max V input controllers. Voc appears without the need of full sun, and goes up when the panels are cold (down when hot). Thus it is an important consideration. It may not blow out the charge controller at first, but it will shorten the life having more than the max V put in every day on wake-up. And if the temps go cold enough ... FWOOP! (Or other cartoon noise of your choice).

The three panels will work in parallel on that controller. That must be what NAWS was saying. If you get parallel and series confused you get the wrong answer or possibly ask the wrong question. It's so easy to do!

Elmer T

Re: Sailboat application

Maybe I do need some expert advice,

I will be installing 3 Kyocera 135 watt panels ( KD-135GX 135 watt 12 volt) then using a Solar Array Combiner (Midnite Solar MNPV-3 3 -circuit array combiner), then on to a Blue Sky Solar Boost 3024iL controller, then to the batteries, 3 each Lifeline 4-D 12-volt batteries.

By the way all of this will be installed on my 45 foot sailboat. I guess my questions are,

1) are these components the right ones, and are they compatable?,

2) do I run the MC-4 cable from each panel to the combiner box, by the way in the box I will be using three (3) AB-15 breakers. From there I will run # 8 AWG wire (+ & -) to the controller, then #8 AWG (+ & -) to the batteries.

3) Should I place the combiner box close to the panels or close to the controller?

Any help and advice will be appreciated.

Thanks,

mike95490

Re: Sailboat application

3, 12V panels in series, may be too much for the Blue Sky input limit - better check that. And if they are all in parallel, you may not see any MPPT benefit unless it's an iceboat.

Cariboocoot wrote: »

Let's get right to the problems, shall we?
First problem: the Blue Sky 3025il has a maximum input Voltage of 57. The Kyocera's Voc is 22.1. You can't put three in series on that controller, as the Voc of the array would be 66.3 - well over the Blue Sky's maximum.

Cariboocoot

Re: Sailboat application

Welcome to the forum.

Elmer T wrote: »

Maybe I do need some expert advice,

I will be installing 3 Kyocera 135 watt panels ( KD-135GX 135 watt 12 volt) then using a Solar Array Combiner (Midnite Solar MNPV-3 3 -circuit array combiner), then on to a Blue Sky Solar Boost 3024iL controller, then to the batteries, 3 each Lifeline 4-D 12-volt batteries.

By the way all of this will be installed on my 45 foot sailboat. I guess my questions are,

1) are these components the right ones, and are they compatable?,

Most of it looks good to me. On a 12V system the Bluesky can handle 40 Amps max. Your likely output from three K135's in parallel is likely no more than 22 Amps.

There's a problem: the 4D batteries are 210 Amps hours each, so that would be 630 Amp hours total. This could be too much battery for the panel. Two would probably work better.

2) do I run the MC-4 cable from each panel to the combiner box, by the way in the box I will be using three (3) AB-15 breakers. From there I will run # 8 AWG wire (+ & -) to the controller, then #8 AWG (+ & -) to the batteries.

The breakers are overkill on those panels. You really only need 10 Amp automotive fuses. That's not saying the combiner is a bad idea. Your wire size is pretty large too: the panels put out less than 8 Amps, typically. Unless you have long wire runs you only need about 12 AWG for the panels. It's easier to handle than 8 AWG!

3) Should I place the combiner box close to the panels or close to the controller?

Whichever way works out easiest/cheapest for you. I can't imagine you'll have very long runs on a sailboat, and if you do then I am so envious!

Now just be patient and wait for someone else to come along and contradict me.

dwh

Re: Sailboat application

Cariboocoot wrote: »

Now just be patient and wait for someone else to come along and contradict me.

No, that won't happen.

Elmer T

Re: Sailboat application

Cariboocoot,

First of all this forum is GREAT, and very helpfull. Thank you for your advice, however in my case of very limited electrical expertise, sometimes the more advice I get, the more questions I have, hope you do not mind.

I am somewhat confused, should my 3 Kyocera 135 watt panels be wired in series, or parallel?

Will the need to use a combiner box with fuses, or breakers depend on which way I wire them, (series, or parallel)?

Is there an advantage to going series or parallel? I understand the difference between the two, but not as to how it relates to charging batteries.

Based on how I wire the panels, will that affect which controller I will need to purchase? The 3024iL was recomended by NAWS, but they may not have understood what I was doing, since I didn't.

In your reply to my first post you mentioned that there was a problem with my batteries, that the 3 of them at 210 amp hours each would be "too much battery for the panel" By panel did you mean the controller (Blue Sky 3024iL)? If so which controller would you recomend?

I have not yet purchased any of the components, however when I do it will be from NAWS, I want to get it right before I do so.

Again, Thanks for the help,
Jeff

Cariboocoot

Re: Sailboat application

Panels should be in parallel in this application so that they do not exceed the Vmax in of the Bluesky.
Each panel should be protected by a fuse or breaker, because there are three in parallel.

As far as charging is concerned, there is no difference between parallel or serial arrangement with this size system. As Mike said there will be little MPPT benefit because the system is small. You could switch to a standard PWM charge controller, such as the ProStar 30: http://www.solar-electric.com/ps-30.html

The benefits of series stringing panels are higher Voltage array to overcome loss in long wiring and possible elimination of fuses if there are only two parallel connections. Example: my four 175 Watt panels are two in series for "48 Volts" and then paralleled. No fuses, because there's only two parallel connections. But I have an MPPT controller to "downconvert" the Voltage to proper charging levels for the 24 Volt system. With a 700 Watt array, I do see some benefit from the MPPT function.

The battery issue is that you don't really have quite enough panel to recharge that much battery. You could expect 21 Amps peak, possibly less if operated in really hot, sunny, tropical paradise areas . As a rule, the recommended peak current should be 5% to 13% of the total battery Amp hour rating. In this case 630 Amp hours for the three batteries would mean a minimum of 32 Amps for 5%. For two of the batteries (420 Amp hours) you're spot-on 5%. But that does not include system losses, heat variations, and loads drawing while charging.

Cariboocoot

Re: Sailboat application

dwh wrote: »

No, that won't happen.

It must: I'm not ready for the world to come to an end!

mike95490

Re: Sailboat application

I suggest on a sailboat, that panels not be in series, as any shadow, can cut off power to the whole string. Bypass diodes are a way around that , and maybe a high voltage string , bypass diodes and luck would work as well too.

Shadows from stays and masts can be a problem

Elmer T

Re: Sailboat application

Cariboocoot,

It's me again...

OK my 3 Kyocera 135-watt panels will be in parallel, If I do go ahead and use the Midnite Combiner MNPV-3, would I take both the + and - from each of the 3-panels into the box, then use a fuse or breaker for each, then combine all of the +'s and -'s and have only one +, and one - coming out of the box going to the controller. (see I told you electrical was not my strong suite). If all of the preceeding is correct, what size breakers would I use? By the way I plan on using the panels that come standard with the MC-4 cables, does that change any of the above logic?

As far as my house battery bank being too big (630 AH's) 3 each 210 amp hour batteries, would I still be able to charge all 3, but it would just take longer, or am I missing somethiong here?

AS always thank you for your help.
Jeff

Cariboocoot

Re: Sailboat application

You've got it!
The Kyocera 135 has a short circuit surrent rating of 8.37 Amps. NEC rules say it should be protected for 1.25 time that, or 10.4625. In my opinion 10 Amps is close enough. That will probably start an argument even though it's a "just in case but probably never will happen" scenario. :roll:

Battery FAQ's: http://www.windsun.com/Batteries/Battery_FAQ.htm
Always a good read.

You've got two factor to consider in recharging batteries. One is "replacing the used Amp hours". For your three 135 Watt panels the basic math looks like this:
405 Watts @ 77% efficiency = 311 / 14.2 Volts charging = 21.9 Amps potential peak current over four hours (typical) "equivalent good sun" = daily harvest of 87.6 Amp hours. If you want a more accurate prediction use the PV Watts calculator: http://www.nrel.gov/rredc/pvwatts/

The 87.6 Amp hours represents less than 14% of your proposed 630 Amp hour bank. Draw the bank below that and you will have trouble "putting back" the power in one day. Typically batteries are discharged 25%-50%(max) daily. The same 'harvest' would be approximately 20% of a 420 Amp hour bank. Much more likely to be achieved with minimal battery discharge. Keep in mind that 87 Amp hours * 12 Volts = 1044 Watt hours (not including losses converting to AC).

The other problem is lower charge currents do not work as well for recharging. There's a rule-of-thumb about having a peak current on 5%-13% in order to minimize sulphation and maximize remixing electrolyte. Some people here have argued this isn't necessarily so, but most have found that if you plan to operate within the guidelines the system is more likely to both work and last.

There's no sense having more battery capacity than you can easily recharge. Possibly the #1 complaint we hear is how the batteries have gone completely dead over a short period of time. Almost inevitably it's due to too much battery/too little panel.

At 420 Amp hours you could, if needs be, use 50% capacity (roughly 2.5 kW hours) in a day and still manage to recover from panels alone, if you allowed them to charge without further load.

Elmer T

Re: Sailboat application

Coot aka Marc,

One last question, then I am placing my order with NAWS.

Is it better to wire my 3 Kyocera 135 watt panels in parallel, and use the Blue Sky 3024iL controller, (which by the way I have NOT yet purchased),

OR wire the 3 panels in series, and purchase another model / size of controller that will work with the increased voltage from wiring the panels in series?

Will either way affect how my batteries are charged?

Thanks,
Jeff

Cariboocoot

Re: Sailboat application

If you wire the panels in series the array Voltage will triple. Then you would have to use one of the more expensive MPPT controllers, like this one: http://www.solar-electric.com/motr45ampmps.html
A bit extreme for a relatively small application with little to no chance of future expansion, yes? That's $100 more for 15 Amps capacity you don't and probably won't have (the three Kyocera's being capable of less than 30 Amps). You'd save three fuses. Not worth it in my opinion.

It's the output side of the charge controller that matters as far as the batteries are concerned. From that POV they don't care how they get their 21 Amps @ 14.2 Volts, so to speak. And the BlueSky does have MPPT function. Plus, as Mike pointed out there can be shading issues with series connected panels on a boat.

I'd stay with the three in parallel and the SB2512 (not the 3024 which is 24 Volt - this isn't a 24 Volt system, is it?) or go with the Morningstar 30 Amp PWM unit if you want to save some $.

BB.

Re: Sailboat application

morning star makes 15, 45, & 60 amp mppt controllers.

Rogue makes a 30 amp mppt controller.

All good, just depends on your needs and preferences.

And other mfg too may make a 30amp mppt... Not at a computer right now to look up.

-Bill

mike95490

Re: Sailboat application

BB. wrote: »

Not at a computer right now to look up.

So, now I gotta ask, how do you post ?

BB.

Re: Sailboat application

Droid smart phone.

4 inch screen with only a soft keyboard and a pretty full function browser.

It is really nice and I can do most anything... But multitasking with soft keys and coping urls, typing numbers, and stuff is a bit of a grind.

-Bill

Elmer T

Re: Sailboat application

Coot aka Marc,

Finally after all of your help and advice I placed my order with NAWS, I purchased 3 of the Kyocera 135 watt 12-volt panels, along with a combiner box, controller, MC4 Cables, etc. OK, when I took the Kyocera panels out of the box, two of them had modules that instead of being black like all of the other modules, they were a "blue color", and had he aperance of "cracked glass:, however the surface was smooth. One panel had 3 of these "blue" looking modules, and the other had one. The third panel did not have any, with all 36 modules the same "black" color. They were all in the standard shipping boxes, with on signs of damage from shipping. Is this normal, or are the panels defective?

As always your help and advice is greatly appreciated.
Thanks,

"getting better at solar" aka Jeff

BB.

Re: Sailboat application

The "fractured blue" panel look is poly crystalline... Typically, the "one dark color" cells (round or squarish cut faces) are mono-crystalline.

Mono-Crystalline cells are usually more expensive and tend to be a little more efficient at generating power--but is not a big difference.

I am not in the solar biz--So I do not know if Kyocera is mixing mono and poly cells on their panels or not... Assuming the cover glass is solid (no cracks/big scratches) and everything else looks fine--and the panels work--you are good to go.

There are "thin film" panels that appear solid black/dark in color--but no individual cells are visible. These are the new low cost panels that many companies are working on the $1.00 per watt cost barrier.

Thin film panels are typically 1/2 as efficient and need ~2x the square footage to collect the same amount of power as mono/poly crystalline panels.

-Bill

mike95490

Re: Sailboat application

The PV glass is tempered, if there is a crack anywhere, it shatters the whole sheet, and the panel will fail in a year or so. The cells under the glass may have a crystallized appearance, but if the glass is clear between the cells, it's OK. Odd, all the panels should be the same. Can you post some photos ??

Elmer T

Re: Sailboat application

Mike 90045,
Yes, I took some pictures, but havn't been able to figure out how to post them. I'll keep at it, if anyone knows how please let me know.

Jeff

Cariboocoot

Re: Sailboat application

Elmer T wrote: »

Mike 90045,
Yes, I took some pictures, but havn't been able to figure out how to post them. I'll keep at it, if anyone knows how please let me know.

Jeff

Jeff;

When you post there is a box below the main one that is headed "Additional Options".
Within that there is a selection of "Manage Attachments" which will allow you to attach pics to your posts.

BB.

Re: Sailboat application

You may need to setup your user options:

User CP
Edit Options:

Visible Post Elements You have the option to show or hide various elements of messages, which may be of use to users on slow internet connections, or who want to remove extraneous clutter from posts. Show Signatures
Show Avatars
Show Images (including attached images and images in

Message Editor Interface When posting messages to the forums or other members, there are three interface types available to you. The simplest of these is a simple text box, while the last is a fully-fledged WYSIWYG editor, which allows you to format your text as you want it and see the results immediately.

Depending upon the capabilities of your web browser, you may not be able to use all of these options. If you experience problems when posting messages, try switching to a different interface type. Message Editor Interface:

Elmer T

Re: Sailboat application

Here is one picture, 2 out of the 3panels I purchased have a number of these "blue color fractured glass" moduals.

Jeff

BB.

Re: Sailboat application

That is normal...

You might be seeing some differences due to polarized light... The light in shade from blue sky is quite polarized--And I would guess that the "fracture" aka multi-crystalline pattern is quite sensitive to polarized light (will look different under direct sunlight or artificial light).

It looks like there is some randomness in how the cells are "rotated" when cut from a silicon ingot and processed onto the panel (again, guessing).

Set your Amp Meter to 10 amps full scale, place the panels all in full sun, and measure the Isc (short circuit current) for each (equal angles facing sun)... You would get within 5% of each other. There should not be much difference in Isc at all under identical conditions.

-Bill