Solar Panels 32' Sloop

[rgleason]

Drcat had the right idea for panel supplier for us as AltE is in Massachusetts and this panel pretty much completely matches the one barnakiel suggested for $189.

https://www.altestore.com/store/sola...#ALTS-165W-12M
58.3" x 26.4" x 1.38" (1480 x 670 x 35 mm)
25.3 lbs (11.5kg)


Two of those are 50 lbs. Moving the anchor to cabin top takes care of 27+ lbs. but I really should move the 28 lb outboard to the center of the boat too, or use more costly flex panels with an aluminum or wood + fiberglass frame to reduce the panel weight by 1/2. That is more cost and also more of my time.

[rgleason]

Elzaar

Thank you for your excellent and informative post accompanied by an explanatory photo of the boat and panels. I do notice how you have turned your radar 180. My radar would be an issue with fixed panels I think, working sometime and sometimes not.

Hopefully if I manage to build the swing and rotate system, the main shadows can be avoided, but there will be several other concerns. High winds and keeping the panels from being hit by the boom or sheet. I'll address high winds by having furling panels that lock or lash into place one over the top of the other in a kind of cover over the top of the outboard. The boom interference issue will be addressed during design and configuration.

As you have done, separate controllers for all panels is best, however wiring identical panels (same voltage and amps) in parallel to a single controller is ok with respect to shading, because each panel will stand alone, and if it is shaded the other one will work fine. It is when you try to wire in series that the panels become co-dependent and both fail badly with shading.

I would love to have some photos of the 8mm double wall polycarbonate backing and how that was done and how it turned out. I assume it is over your canvas and helps to support the panels and provide some cooling air on the backside. It would really help to know how effective that is, perhaps by holding some paper in front of the openings and seeing how hot the air is coming out.

Also some detail shots of the installation would be great.

Thank you Elzaar

First Mate Marine has a great website. The photo below of an adjustible panel on a stick is from that website. He has some good photos of installations and equipment along with a complete list of panels available. Thank you.

https://www.firstmatemarine.com/
marine-solar-panels.html
charge-controllers-and-wire.html
Featured_Products.html


There are many expensive examples of adjustable solar panels on poles.
Google images
Custom Marine Products
Custom Marine Products Top of the Pole kits
Solar Panel Store - Pole kits
Emarine Solar Mounting kits

However the less expensive route is to use ingenuity and appropriate found hardware, such as Gemini fittings and aluminum pole manufacter hardware, etc. combined with fabrications and installation work.

I would very much like to combine two adjustable (even tracking) poles with two bifacing panels if they were not too expensive. 2 x 100w might be adequate.

[gonesail]

2 kyocera 85 watt panels with blue sky controller .. 40" x 26" each .. on a 30 foot sloop. they keep up with the small refrigerator along with inside fans and LED lights. mounted behind boom and above bimini.

[rgleason]

Thanks Gone Sail.
We have one Ozifridge Danfoss, B&G Chartplotter & 4G Radar, all LED lights interior and nav lights, no windlass, no HF Radio, no watermaker. We estimate our use as follows:

Cruising -Sail & Anchor : 100 amps/day
Voyage: 140 amps/day

Regarding small tracking solar equipment

DIY Miniature Solar Tracker
Single axis and Dual Axis Tracker
MTM Tracker $61 - ready to install
Alibaba search

If you are looking for reasons not to do it, here they are:
Why we don't sell solar trackers
Advantages and Disadvantages of a solar tracking system

It is inevitable that as the efficiency improves and we get bifacing panels, that tracking will become more prevalent because of the 25% efficiency gain.

Maybe we should not be quite so aggressive about the size of the panels, it would help get this so it works better. (2) 100w panels $140 each? Figure we'll be motoring at least 1 hr per day anyway. The 40" is almost exactly the width of our stern. Total weight of 2x16=32lb is better.

------------------------------ALTS-100w-24P
Peak Power 100 Watts
24 V Voltage at Max Power (Vmp) 36.23
Current at Max Power (Imp) 2.76 A

Open Circuit Voltage (Voc) 44.8 V
Short Circuit Current (Isc) 3.04 A

Max System Voltage 600 Vdc
Module Efficiency 14.63%
Dimensions 40.2" x 26.4" x 1.4"
(1020 x 670x 35mm)
Weight 16.5 lbs (7.5kg)

Connectors/Cables MC4 Compatible

Connector Cables (+ on right; - on left) Number of Cells 72 Polycrystalline cells Operating Temperature Range -40°C to + 85°C

[rgleason]

As long as we don't use or computers so intensely, 80ah/day will be fine while cruising. Our batteries are FLA (2)Trojan T105 215ah, but I would like to get Lifepo.

Here is a pretty good account of panel performance in the great lakes.
https://www.custommarineproducts.com...0solar%20panel This account is for one panel of various sizes on succeeding years (130w, 140w, 160w) and we are considering (2) 100w right now.

[barnakiel]

aaaahhhh .....


6V batteries? but you mean the bank is 12V yes?


You Americaines always puzzle me with your deep cycle love for 6V ;-))))


One of the pair dies ... and you have nothing to put all those solar Amps into! No, not critical, only AMAZED.


I do not think you need to worry at all about computers though, unless maybe you mine BTCoins on passages or something (render CG videos in 4K ?).


Us, anchored, use one and at times two laptops most of the day (when not out and about trekking the islands). I use one very extensively to process images, upload them, etc.


How we solved our computer thing is by getting fine 11 and 14 inch laptops of pretty recent build. These use 1A each. If I truly push the bigger one it will touch 2A for a moment then quickly settle back at 1.4 A or thereabouts.


2A x 10 hrs = 20Ah only!!! And since we tend to start our laptop games not before our coffee time (to me 11:00 solar time) then the laptops do nothing to our daily solar cycle as at 11:00 the panels are already providing way more than our batteries can accept. So our laptops, tablets and router only accept the otherwise lost extra capacity.


You can do even better, if you can afford HQ laptops with prime components. Ours are rather economy class. Actually the smaller one still has a spinning drive.



Do NOT worry about computers: start your computing when the batts are no longer bulking the Amps and that's that. Otherwise start making ice cubes. If you do not, that part of the capacity (once your batts reach X % ) will be lost. And your Campari will be way too warm.



Cheers,
b.

[rgleason]

Barnakiel,

Good points, timing and use of loads and reducing loads by turning down display lights and having SSD on newer low powered computers are key strategies. Using computers from 11am on when there is excess power makes good sense.

We had anemic batteries (2) FLA 72ah 12vdc in parallel. Because the box is big enough, I can fit (2) golf cart Trojan T105 6vdc batteries ($160 each) in series which is 215ah 12vdc. I don't like running the engine & 65amp alternator many hours (4-5) to get trailing amps down to 2%. Solar will help a lot.

Eventually I would like to have lifepo batteries but will need to rewire entire system. The problem is finding a better place for electrical components in the cabin rather than under the port cockpit locker seat which is where the batteries, Genasun 10a controller and one small 6 circuit panel for direct battery connects (2 pumps, solar, etc) are now located.

I have picked (2) ALT100-24P 100w 24vdc Poly ($148) solar panels with Vmp=36.23 amp Imp=2.76 and I am considering wiring them in parallel due to the issue of shading, even though the stern arms will permit swinging and rotating.

Now I am trying to decide about the ultimate configuration when I move the batteries and change to lifepo, I could reconfigure the controller to output 24vdc rather than 12vdc. What would the advantages be? I would also need another device (Sterling DC to DC converter for powering my 12vdc distribution panel). Also I would probably want a 24vdc alternator at the same time (I have another thread about that). There are advantages to having a 24vdc alternator, less heat, smaller cables, better output and charging. I would have to check if small case 24vdc is available. I haven't really considered this in depth...but 24vdc also saves on size of cabling from the solar controller to the batteries. To do this must I have the solar panels in series to get the new Victron Smartsolar MPPT 100/30 controller ($190) to kick in early in the morning? Couldn't I drop down to 100/20 and still leave room for a 3rd identical panel? Any other suggestions?


I found these two videos very helpful in considering configuration of the solar installation.

Comparing + Sizing MPPT vs PWM Solar Charge Controller

Battery Bank Options + Wiring Solar Batteries from 6v to 12v vs 24v

[rgleason]

For the Sterling DC to DC I think 24vdc to 12vdc 70amp is more than I need, at $430, but the only other one is 30a. I have to keep in mind that this is saving cable costs for a new alternator and solar controller to the new relocated batteries (longer run) and one of the disadvantages is I have to find a place for this equipment in the cabin too.

Thinking about this further. 200ah of LiFePo x .3C (max charge rate for the alternator) = 60a. However the alternator should be generously oversized for longevity and continuous use and it must be cooled properly and driven properly, so 60a x 1.5= 90a.
So it appears a 100a alternator which really should be a serpentine belt, would probably work fine provided there was adequate cooling. Should it be 12v or 24v?

[newhaul]

Originally Posted by rgleason

For the Sterling DC to DC I think 24vdc to 12vdc 70amp is more than I need, at $430, but the only other one is 30a. I have to keep in mind that this is saving cable costs for a new alternator and solar controller to the new relocated batteries (longer run) and one of the disadvantages is I have to find a place for this equipment in the cabin too.

Thinking about this further. 200ah of LiFePo x .3C (max charge rate for the alternator) = 60a. However the alternator should be generously oversized for longevity and continuous use and it must be cooled properly and driven properly, so 60a x 1.5= 90a.
So it appears a 100a alternator which really should be a serpentine belt, would probably work fine provided there was adequate cooling. Should it be 12v or 24v?

renogy also makes a good b2b charger at less than half the price of most other 40 amp units .
https://www.renogy.com/renogy-12v-dc...ttery-charger/

And they are considering a 60 amp unit soon .

[rgleason]

I made an error.

LiFePo 200ah @ 12vdc is 100ah @24vdc. So 100ah@24vdc x .3 = 30amp for the alternator.

Alternator 30a@24vdc x 1.5 for heat and durability= 45ah @24vdc. So an alternator 50a or 60a @ 24vdc would work.

Delco makes 10si and 12si in 24vdc and I am sure there are more recent ones. I don't believe these will fit in a small case slot however (YM-3YM-30)


Newhaul, I won't need much more than 20amp will I? It's going into a 12vdc FLA battery and the worst loads are
1. Navigation- chartplotter, radar, autopilot - varies
2. Computer 5a -varies
3. Refrigerator 5-7a varies because it is eutectic and we run it with the engine when possible.
Maybe I should get the 30a.



Thanks for the Renogy link. Very helfpul

[newhaul]

Originally Posted by rgleason

I made an error.

LiFePo 200ah @ 12vdc is 100ah @24vdc. So 100ah@24vdc x .3 = 30amp for the alternator.

Alternator 30a@24vdc x 1.5 for heat and durability= 45ah @24vdc. So an alternator 50a or 60a @ 24vdc would work.

Delco makes 10si and 12si in 24vdc and I am sure there are more recent ones. I don't believe these will fit in a small case slot however (YM-3YM-30)


Newhaul, I won't need much more than 20amp will I? It's going into a 12vdc FLA battery and the worst loads are
1. Navigation- chartplotter, radar, autopilot - varies
2. Computer 5a -varies
3. Refrigerator 5-7a varies because it is eutectic and we run it with the engine when possible.
Maybe I should get the 30a.



Thanks for the Renogy link. Very helfpul

for the extra $50 I would just get the 40 amp unit . If you don't need it fine but if you do it can put that out.
Also leaves wiggle room for future upgrades .

[barnakiel]

Originally Posted by rgleason

Barnakiel,


I have picked (2) ALT100-24P 100w 24vdc Poly ($148) solar panels with Vmp=36.23 amp Imp=2.76 and I am considering wiring them in parallel due to the issue of shading, even though the stern arms will permit swinging and rotating.

To do this must I have the solar panels in series to get the new Victron Smartsolar MPPT 100/30 controller ($190) to kick in early in the morning? Couldn't I drop down to 100/20 and still leave room for a 3rd identical panel? Any other suggestions?

Parallel is fine because the panels are 24V already, so you do not need to stack them up (and build up Voltage). 24V panels will wake up the regulator as soon as there is any sun up. Only 12V panels, single, or in parallel 'suffer' from this unfortunate morning lag (and only on some regulators, our older PWM regulator had zero lag).


So you do not need to bump up voltage now that your panels are 24 and you batteries are 12.


Whether you need the bigger or the smaller regulator depends again on how you wire things.


In series, 3 panels will yield 36.23V x 3 = 108 V. This looks above a 100/X regulator. I would not go this way.


In parallel, 3 panels will yield 2.76A x 3 = 8.28 A. This is OK on the input (solar) side but on the output (battery) side, with the 100/20 model, you may be limited in max output. Because 300W / 12.5 (batteries early in the morning) = 24A. Hence the smaller of the regulators will be somewhat under par. I do not think it would burn or something but it would deliver only 20 A to the batteries. And the point with mppt regulators is to suck up every Amp available from the panels. So, imho, the 100/20 model is fine with 2 panels, but under par with 3.



To sum up, I would personally use the bigger model (100/30) - if you think you want to expand the system any time soon (within next 10 years or so).



I suggest having the 'Smart' version of the Victron toy (I say this again - becauase the older non-smart versions did not have BT built in). The older ones were labelled BlueSolar, the newer ones are labelled SmartSolar. And they have a BT logo on the faceplate.



You may want to download the 100/30 and 100/20 manuals and double check if my assumptions are on the right track. The way I remember it the first number is max Voltage of the solar array (100V) while the second number gives max A rating (at each end) - so e.g. '20' means that the regulator will accept max 20A current from the panels and also deliver max 20 A to the batteries.


Check the above carefully as old men tend to be wrong at all times ! ;-)


PS in our boat the reg is 75/15 with only 150W/12V solar and 100Ah battery. I can see 8+Amps charged at times when in the West Indies. Thus I think with your 300 W panels at 24V you are taking the 100/30 regulator (up to 3 panels, in parallel). 2 panels would be fine on 100/20 BUT this is not a future-proof solution.



Cheers,
b.

[rgleason]

It looks like Balmar's Series 6 would work at 24v and would not require serpentine belt because it appears to be well within the specs!! - Big savings. It says a "Max Charge Regulator Kit is required for 24 volt", and I have an ARS-5 , but the MC-614 is needed to regulate to 24vdc, however I haven't yet figured out regulation. I do have Al Thompson's Gen3 VSR board, so that is very flexible and will do 24vdc regulation too.

6-Series Alternators | Balmar ($600) Anyway Balmar 60-70-SV is about $600 without a serpentine belt, however there may be some 24vdc alternators that fit.

[barnakiel]

I have just had a quick look at LiFePo4 batts at our car supply and they look 11 USD / Ah. This is about 11 times ratio over my present lead batteries. Even at 2x the usable capacity, it still looks 4 times more expensive per Ah, even after the extra life time chucked in.


And I was looking at plain China made stuff. Did not look all that trustworthy to me.



Where do you get your Lithium batteries so that they make $-wise sense? I am clearly looking in the wrong place.



b.

[newhaul]

Originally Posted by barnakiel

I have just had a quick look at LiFePo4 batts at our car supply and they look 11 USD / Ah. This is about 11 times ratio over my present lead batteries. Even at 2x the usable capacity, it still looks 4 times more expensive per Ah, even after the extra life time chucked in.


And I was looking at plain China made stuff. Did not look all that trustworthy to me.



Where do you get your Lithium batteries so that they make $-wise sense? I am clearly looking in the wrong place.



b.

I get mine from China that is where at least 90% of the Lfp brands are actually made.