Solar Afloat

Highland_Fling

I may be in the wrong place but this web site looks good so here i am.

I have a number of questions.

First i have a 46 foot sailboat in the Caribbean and want to live without too much use of the engine and or a generator we run twin Danfoss compressors for the Fridge and Freezer a PC and an Inverter. We have about 600AH of house batteries and a 90A alternator. When sailing i am assuming the engine use leaving and arriving at an anchorage will handle all the sailing 12V loads though obviously lots of solar will have a positive impact on the need for the batteries to be charged by burning diesel.

As the boat sits on the hard during the hurricane season i put on two RadioShack 15W Sunforce panels to keep the batteries alive - they were on sale with a crazy discount - so cheap it was hard not to choose them.

I then put on a Morningstar Sunsaver MMPT 15L controller. I spent some serious $'s on this one as i was intending to upgrade the solar and thought that this would be a good starting point however it will only handle 200W and i think i need more solar.

As an upgrade i was looking at initially two then four Kyocera KD-185-GX-LPU panels as the final solution however this means i need to upgrade the controller to a Morningstar Tristar MMPT 45 or 60. Seeing as i put a too small controller on the last time i think i would purchase the bigger 60 amp controller.

I wanted to maximise the output from my two small solar panels so i went down the MMPT route BUT looking at the difference in cost between a Morningstar PWM 60 and a MMPT 60 i am wondering/questioning if i should buy the MMPT version- will i really get a better bang for my buck? Is this a cost effective move will it pass a cost benefit analysis examination seeing as there is a significant cost difference?

Now i have another question as an interim first move i was thinking of two 100W panels which the MS MMPT 15L could control i saw the SunWize SW100C on the NAW&S web site BUT did not understand these words "
Because this module has 48 cells connected in series, it is not considered a true 12 volt nominal module." KUNFOOSED is ME

Next question assuming i am going to put on four 185W or 205 or 210W bigger panels in series they generate a scary voltage 1 string with 4 panels 116V 2 strings of 2 panels each obviously half that. So should i put four panels in two strings on a boat or leave them all in one string to maximise the output early in the day and as the sun goes down since four panels in series will obviously get into a charging output mode before two separate strings would or have i got that wrong or is this marginal or what?

Next question i thought Kyocera KD panels had a waterproof connector box on the back of the panel and not these MC style connectors and the Kyocera KC had they MC connectors have i got that the wrong way round also are the KC connectors suitable for a marine environment wrapped in self amalgamating tape of course.

enough for a first post methinks

all thoughts suggestions welcome

kindest regards

David

Cariboocoot

Re: Solar Afloat

That's a lot of info to digest. No wonder you're confused. I think I'll join you!

First off, your two 15 W panels are doing diddly for a 600 Amp/hr bank. You might get 2 Amps out of them, which isn't even enough to stay ahead of the self-discharge rate if these are FLA's. While the boat sits idle you need some better form of battery maintenance. More panels would be nice, but here's always a problem with finding space to fit panels on a boat, even a 46 footer! If you can work out where you can put what panels your halfway home.

That 15 Amp charge controller is also not up to the task of fully solar-charging that bank. Although it could handle a maintenance charge. (It's a waste of time to have MPPT with 30 Watts, btw. You won't see the benefit with such a small array.) 600 Amp/hrs of battery would like to have 60 Amps of current for complete charging, and that would mean the bigger charge controller and roughly 1000 Watts of panels. At that you probably won't see full current; tricky on sail boats to keep the panels aimed at the sun and keep the rigging shadows off the panels.

As for the "not truly 12 Volt panels", this is because nominal Voltage is not the same as Vmp; where the panels actually operate at maximum power. There are some panels out there which have a Vmp too low to be "truly" 12V or 24V panels: they won't operate at levels capable of providing the full charge or equalization Voltages. 12 Volt systems actually charge at 14.2-14.4 Volts and EQ at 15.

But here's the good news: with an MPPT controller it doesn't matter. You can wire two of these "off" panels in series and get double the array Voltage. The charge controller will down convert this to proper levels for the system. So they can be used, providing the output doesn't exceed the controller's maximum input.

Are you more confused now or less so?

Highland_Fling

Re: Solar Afloat

Yes i did ask too many questions in the first post that was confusing i should have simply asked one question. in one post to keep things both simple and sensible.

One thing i really dont like is the way this forum has the last post at the top - that is a strange way to present things - in my world - and it is at odds with all the other forums i am on that use this identical forum software where the first post stays at the top with subsequent answers appearing below it. Can you change the topic view so it becomes initial post first? YOU CAN and i DID

Well there is theory and there is the practical - the two small panels do keep the batteries happy We leave the boat for up to six months at a time and the batteries are always good to go when we arrive at the boat.

STILL KNUFOOSED on this solar panel how can that not be a 12V panel

Model - SW100C
Rated Power - 100W (Watts)
Rated Voltage - 23.0V (Vmp)
Rated Current - 4.35A (Imp)
Open Circuit Short Circuit - 28.5V (Voc)
Short Circuit Current - 5.00A (Isc)


The first step will to try two 100W panels with the MS MMPT 15L controller as that is as much as it can handle i was thinking of these SunWize SW100C modules

From the W&S web site.

SunWize SW90C/SW100C modules deliver top-quality performance for all photovoltaic applications including rural electrification, water pumping, telemetry, communications, and general battery charging. SunWize modules can be used in single-module and multiple-module installations and are ideal for high voltage grid-tied inverters. Each module consists of 48 solar cells connected in series providing maximum charging power.

The monocrystalline cells are encapsulated and bonded to the glass in multiple layers of ethylene vinyl acetate (EVA) and laminated with white Tedlar backing insuring long life in severe environmental conditions. The glass surface allows maximum light transmission and is impact resistant to hailstone forces up to 5 ft-lbs. A weather resistant junction box accommodates all wiring methods including moisture tight strain relief connectors and electrical conduit.

Because this module has 48 cells connected in series, it is not considered a true 12 volt nominal module. When three of these modules are connected in series, they are ideal for a standard 48 volt PWM charge controller. If used for charging a 12 or 24 volt battery system, we recommend using the Morningstar SunSaver 15 amp MPPT charge controller. You can wire two modules in series to the controller for a 12 volt system and four modules in series for a 24 volt system. If a higher wattage array is necessary for a 12 or 24 volt system, any of our higher amperage MPPT charge controllers will work. If you need any help sizing a larger MPPT controller for your system, feel free to call our office and our sales staff will be happy to help you with that.

So if this panel has 48 cells in series what does a 'normal' 12V panel have ?

Two of these will give me 15Amps all day long 12 hours of sunlight will generate if needed 128 A/H OK to be more realistic lets say an average of 10 amps for 10 hours a day that is still 100A/H - when i start my engine i get an instant 20 Amp charge which in 45 mins is down to around 2 or 3 amps so i think this is a good first step without replacing the controller anything more powerful means i have to change the controller.

thanks

David

BB.

Re: Solar Afloat

Regarding how the forum displays threads... Click Here (User CP/Edit Options).

You should be able to set the forum for your needs (within reason). I use Linear, oldest first....

Yes, you asked a lot of questions, and it takes a bit of free time to get a fully documented post together... Give us a bit of free time--we are all volunteering our time here.

-Bill

Highland_Fling

Re: Solar Afloat

BB. wrote: »

Regarding how the forum displays threads... Click Here (User CP/Edit Options).

You should be able to set the forum for your needs (within reason). I use Linear, oldest first....

Yes, you asked a lot of questions, and it takes a bit of free time to get a fully documented post together... Give us a bit of free time--we are all volunteering our time here.

-Bill

thanks i dont see a thanks button i did look at the user CP options and changed my view to L/O/F

Cariboocoot

Re: Solar Afloat

Normally the Vmp on a "12 Volt" panel is around 17 Volts. At 23 Vmp, these panels are a tad high for 12 V and too low for 24. But as they suggest, used with an MPPT controller this "problem" isn't a problem anymore. With a PWM type controller the panels will try to raise the Voltage too much and the batteries could be cooked (over-charged) as a result.

Two of these 100 Watt panels should yield around 10 Amps (peak) of charging current. Could be a bit better (derating for sail boat install is a wild guess). Not much against a 600 Amp/hr bank, but certainly better than the 30 Watts you've got now!

Remember that the Wattage rating on a panel is a "peak" rating done under a controlled laboratory test. It does not reflect what you'll actually get out of them in your particular installation. As a rule-of-thumb you could count on an average of 80% of the rated output over the "equivalent good sun" hours for a site. What that would be on a sail boat ... again, it's "wild guess" territory because of all the variables.

What type of batteries are you charging? I still suspect you may have a chronic under-charging condition, which will not manifest itself right away but rather shows up in the form of shortened battery life due to excessive/rapid sulphation.

Highland_Fling

Re: Solar Afloat

Cariboocoot wrote: »

Normally the Vmp on a "12 Volt" panel is around 17 Volts. At 23 Vmp, these panels are a tad high for 12 V and too low for 24. But as they suggest, used with an MPPT controller this "problem" isn't a problem anymore. With a PWM type controller the panels will try to raise the Voltage too much and the batteries could be cooked (over-charged) as a result.

Two of these 100 Watt panels should yield around 10 Amps (peak) of charging current. Could be a bit better (derating for sail boat install is a wild guess). Not much against a 600 Amp/hr bank, but certainly better than the 30 Watts you've got now!

Remember that the Wattage rating on a panel is a "peak" rating done under a controlled laboratory test. It does not reflect what you'll actually get out of them in your particular installation. As a rule-of-thumb you could count on an average of 80% of the rated output over the "equivalent good sun" hours for a site. What that would be on a sail boat ... again, it's "wild guess" territory because of all the variables.

What type of batteries are you charging? I still suspect you may have a chronic under-charging condition, which will not manifest itself right away but rather shows up in the form of shortened battery life due to excessive/rapid sulphation.

I think either GEL or AGM cant remember and the boat is 4000 miles away so cant have a quick look :grr:cry

Surely 25 A/H per day is more than enough to trickle charge five batteries and keep them happy one engine start 4D and four 8D house batteries seems to be fine so far and been running for more than a year now.

Presently the panels are angled at 70 or so degrees into the sun and as the are on the back of the boat pointing aft and as the trade winds blow from E to W the boat is generally pointing at the sun most of the day except when running downwind .

BUT lookie here two of these solar panels and a FREE MS MPPT 15L controller

http://www.solarblvd.com/p2396/Two-Sunwize-100-Watt-12-Volt-Plus-Morningstar-SS-MPPT-15L-Free!/product_info.html

regards

David

marinebattery

Re: Solar Afloat

Hello BB! You were so helpful to Highland Fling, I thought I would ask a question here. If I am wrong in asking this here I know you will tell me where to go. lol

I am trying to learn about solar panels & solar batteries. It will be important in my business soon, I hope. So much great info here. This question however, is to help me out now & to share with others at my marina. What are the best well-made solar panels for boats? How do you choose the size?
I would so appreciate your help. No one at the marina uses solar power. I think that should change. I am very involved in spreading the word about new safe & clean energy. I push recycling & belong to organizations trying to educate people about Climate Change. Solar energy just follows the way I live.
Thanks so much for your help.

Marine Batteries

mike95490

Re: Solar Afloat

marinebattery wrote: »

No one at the marina uses solar power.

That's because shore power is cheap. Real Cheap. like .20 KWH. Solar is like $2 KWH

marinebattery

Re: Solar Afloat

-Bill[/QUOTE]

mike90045 wrote: »

That's because shore power is cheap. Real Cheap. like .20 KWH. Solar is like $2 KWH

Thanks Bill. Almost all those who are members of this marina don't care about that. They just need to be informed.

I need info in order to do that. Is this the wrong place to ask who the best manufacturers are? Just an opinion, of course. I need some quidance. If I knew the names of the manufacturers of solar panels, well made ones, I could Google them.

Can anyone give me some info.

Marine Batteries

mike95490

Re: Solar Afloat

I can't recall if unisolar still makes flexible panels for sail boat decks. Most panels are NOT rated for marine use, and may not last their full lifetime in salt spray - the mounting frames will rot out.
The big problem on boats is shadows from masts and stays. On speedboats, it's the pounding thru waves. And if a panel catches a wave in bad weather, it's likely going to be missing when the water clears.

But, a couple of well placed panels can extend time at anchor before starting a generator. It's just that using panels needs to be a major change in folks mindset about using power - have to flip it to conserving power.

Kamala

Re: Solar Afloat

You could browse the store of the business that hosts this forum:

Northern Arizona Wind & Sun

BB.

Re: Solar Afloat

As Mike said, off-grid solar power is horrendously expensive (~10x the cost) compared to shore power in most (at least domestic) ports.

As for what is the best battery for boats--More or less it is probably AGM. They are "sealed" and spill proof. Can be mounted on their sides or standing up, and are much cleaner flooded cell batteries. All this comes at 2x the cost of standard flooded cell batteries and probably a shorter life (the catalyst used to recombine the H2 and O2 corrodes over time).

Add the requirement that solar panels face the sun with no shade (typically between 9am and 3pm at least)--and that boats may not have a choice of direction to point the solar panels, free of shaded from lines, masts, sails, etc... It makes it a difficult sale.

Not to say that people have not mounted solar arrays to various types of boats--forexampleopen ocean sailing races (no motor power allowed) or for boats that anchor at remote locations for weeks on end (noise, smoke, cost of fuel from aux genset) can make good use of solar panels.

But, to use solar on such a boat requires a lot of work for conservation... Changing running lights and cabin lights to low power LED, navigation equipment and radios to low power devices, etc. all helps. Even then, a few days of bad weather and you have drained your battery bank--and need shore power or aux genset to recharge the battery bank.

Things like on-board refrigerator, fresh water purification systems, etc. all take a lot of power and many smaller boats may not have enough clear area to mount solar panels.

Plus the panels are (typically) 1/8" tempered glass... Fairly strong--but any hard object dropped on the surface is going to render that expensive panel useless... And the flexible plastic panels tend not to last very long in a salt water environment (maybe a year or so at best??).

Given the limitations, do you see applications that you can help people with?

-Bill

marinebattery

Re: Solar Afloat

Well, thank you Bill, Mike, Kamala & BB. What a great forum. Your information has helped me immensely. I was under the impression it was a much simpler transition. I think I will have to rethink this.

What about solar batteries. My business, as I said, involves marine batteries. Hence, the profile name. I've had that for a long time! I am not here to sell anything. Please believe me. No reason for me to tell you about my business other than being honest with you. I do not carry any solar batteries. I quess I really should if I really want to help in any way I can, no matter how small.

Getting back to going solar, what about solar batteries? Is there conversion involved there too?

I am grateful for your help. So glad I found you. I hope to be a member of this forum for a long time to come.

Thanks again. I hope I can help someone out one of these days.;)

mike95490

Re: Solar Afloat

Solar batteries, are nothing more than a good deep cycle battery. Marine batteries are often a cross between a starting battery, and pure deep cycle. Deep cycle batteries aren't designed for the huge surge neeeded by the starter motor.

Again, this forum's host site has info and sales of the batteries.
http://store.solar-electric.com/batteries.html

BB.

Re: Solar Afloat

Solar Batteries... The first difference is usually the warranty. Some (many?) companies will only cover solar/off-grid installation warranties for their "solar batteries".

The next difference for boats is how far they can operate tilted (boat rolling/sailing) without dumping electrolyte out the caps. Are "marine batteries" designed better for off vertical operation--You may know better than I.

Then, you have the physical advantages of AGM type sealed batteries. In normal operation, they don't vent during charging so they are cleaner. They are also less likely to spew poisonous gasses if covered by salt water (you don't want to be around a large bank of flooded cell batteries with a partially flooded boat). And you don't have any need to check water levels or refill with distilled water.

A couple of down sides--AGM's are expensive. Do not tolerate overcharging (high charging voltage) at all (they will vent and die an early death). And because you cannot monitor their specific gravity with a normal hydrometer, you are left with guessing state of charge by measuring resting voltage and/or adding a Battery Monitor (or this other brand) to watch the cumulative current into/out of the battery bank (I like battery monitors, but they are not perfect either).

And there is always lots heated discussion about desulfators (has resulted in at least one deleted thread here) and if thickness of battery plates makes for a better deep cycle battery (thin plates are typically used for automotive batteries and thick plates tend to be offered on higher priced deep cycle batteries). There are people on both sides of the arguments here.

In the end, taking good care of the battery bank goes a long way towards providing a long life. A couple of good Battery FAQ's to read:

Deep Cycle Battery FAQ
www.batteryfaq.org

Other issues about how deep you cycle your batteries or how much to pay for a set of batteries many times results in ambigious answers...

I.e., if you double the size of your battery bank it may last a bit more than 2x as long. If you spend twice as much for a "high end" deep cycle battery, it may last 2x as long too. Or if you get an industrial traction battery--It may last 15-20 years, but you need more solar panels (higher self discharge rates) and more distilled water (typically off-gas more hydrogen during charging)--which drive up your costs and maintenance time.

If this is your first trip into off-grid, you might want to get a "training set" of "golf cart" style batteries. OK quality and not too expensive (although, everything is going up in costs these days). You may get a 3-5 years of life from them and you can see what mistakes you will make without bankrupting yourself (too little solar power, too much load, somebody forgets to turn off a light and kills the bank, no generator backup for bad weather/heavy loads, etc.).

-Bill

marinebattery

Re: Solar Afloat

Well, once again I thank you all. I now have so much to digest. To be honest, I didn't expect so much knowledge. You guys are something. I checked out the links, BB. I bookmarked them! Really a great find for me.

I sell AGM's so at least I know that much. BB, the tilted question is one I will check into also. Interesting observation. Also Mike suggested Solar batteries are deep cycle only. Another important factor.

I appreciate all of your help. I'm happy to be in this group. I'll report back and let you know how it all worked out. I'll be following what else is going on here until then.

Excuse me if I am profuse in my appreciation. I just enjoy people who are nice enough to go out of their way to help. Isn't always the way these days.

I'll be back!

Marine Batteries

Kamala

Re: Solar Afloat

marinebattery wrote: »

... What about solar batteries.

bryanl should weigh in on this. He has displayed a, well reasoned, penchant for "debunking" battery types/constructions based on marketing/intended use.

K

marinebattery

Re: Solar Afloat

Well, hello again. What a sudden turn of events. The weather turned ugly right before Labor Day and has stayed that way. First the hurricane was a threat. Many folks took their boats out of the water. The smaller ones at least. We received a few drops of water. Very glad. Didn't want all that comes with a close to the coast storm. However, since the holiday, the weather has been grey and cold. It might go down into the high 30's one night this week! What is this? Any of my goals of solar power will have to wait. Hopefully the season will start up early next spring.

I am looking at adding solar power to my business. Solar batteries. I'm thinking about it. The marine battery business is not what it used to be. Need to expand. I'll be in touch. Thanks everyone. Any advice? I would be happy to hear it. As usual, it is a pleasure to be here.

Marine Batteries

marinebattery

Re: Solar Afloat

Well, it's been almost 2 months since I last visited this forum. I was so thrilled to have so many members offer help. I have started adding Rolls Surrette solar batteries to my site. They are expensive but have a life expectancy of 7-15 years. I am interested in knowing if anyone has any suggestions for other solar batteries. Any personal experiences with a particular type? How about Deka Solar? I have been very upfront about my website. I want to offer solar products. I'm just not very knowledgeable YET. I'm learning as I go. I'm hoping for suggestions. Although my site started carrying only marine batteries, I really need to expand. Thanks for any assistance.

BB.

Re: Solar Afloat

Deka has some pretty good comments here...

An easier way to search here is to use Google and the "site:wind-sun.com" keyword (limits your search results to just one website):

• Deka site:wind-sun.com

I got ~269 hits here on "Deka" (probably multiple posts in one thread, etc.)...

-Bill

Kamala

Re: Solar Afloat

I am extremely pleased with the performance of my East Penn 8AGC2 batteries. Deka is one of East Penn's many imprints which include ProMaster (golf cart) and SunExtender (renewable energy) among a few others.

I purchased them from a local distributor and they carry a Northern Battery label. The C/20 rate of these batteries is given as 187AH. An uncommon AH value. While shopping locally, by telephone, my distributor assured me that these batteries were 220AH (which, I seem to recall, is true at a C/100 rate.) As it turned out, it didn't matter. I've never reached 50%.

I offer these statements to make the point that East Penn did not overstate the capacity of these batteries. My distributor should have had a better understanding of C rates, but as I said, it doesn't matter. The bank has performed beyond my expectations.

Trojans seem to be a standard. Surrettes (isn't that Rolls?) are for the elite or very large systems. And there is the ubiquitous Chinese. My distributor tried to steer me toward FullRiver. They carried them and the price was lower but I did not like their website.

My distributor could not provide any spec sheets on the 8AGC2's but happily loaded the batteries into my vehicle. I brought them home and sent an email to East Penn requesting the charging specifications. I received exactly what I needed within 48 hours.

I can enthusiastically recommend East Penn as a U.S. manufacturer of quality lead acid batteries.

K

marinebattery

Re: Solar Afloat

Well, once again I have to thank BB & Kamala for being so generous. I am so happy I found this forum last August. Every time I ask for help I get great responses. It is always relevent and very helpful.
I find this so amazing at a time when so many don't want to help others. So, thanks so much. This info will really help me.
I suppose I will be back soon. I have so much to figure out. It is always a great experience. Bye for now.
p.s. BB. I push Deka all the time. Love the company, love the batteries.

Marine Batteries

BB.

Re: Solar Afloat

Marine battery,

I was reviewing the thread and saw that we still may not have answered all of your panel voltage/solar charger questions.

If you still need some clarifications, please feel free to ask/reword them again.

-Bill

marinebattery

Re: Solar Afloat

Thanks BB. I think I have what I need now. This time around I just wanted to know what solar batteries you thought where better than others. I am going to start adding Deka's now. I have Deka, just not the solar. Thanks again. I'm quite sure I will need more info at some point. When I do, I'll definately be back here. Where else would I go!
Have a great week.


Best Regards,
Robin