Solar Panels 32' Sloop

[rgleason]

Newhaul has just advised:

Ok first off, flex panels are not actually flexible long term they are best mounted to some surface that is basically rigid. The panels will flex to match the contours of the surface they are mounted on. The main thing is they are lighter than rigid ones.


First go with the 18v panels they will be able to charge the battery in an emergency situation by direct wiring.
...That being said you are using mppt controllers correct ?
Wire both stbd panels in series to a single mppt controller
Do the same with port panels, through their own mppt controller.
That will give you optimum charging capacity.


---Thank you Newhaul! That confirms that this is the correct approach.
It would be the "Second Best" version in the post below.

[barnakiel]

Bloody Mary and the Saints! The Internet has swallowed my long and ah so elaborate a reply.


OK, I will briefly sum up then:


Your stern shows space for 3x12V 165W panels. 495W, pretty cool vs. 350W you mentioned. 1.5USD/W, reg,cables,fuses included.



These are 1500 mm long, 670 mm wide and 30mm deep, weight 11 kg each.



These take 100 / 30 regulator. (in series)



This places you at 500W @ USD 800 or thereabouts, reg, cables, fuses inclusive.


Read 5 to 30 A into 12V batts any time the sun is shining.



Start by hanging them one each side of the quarter and one behind the boat. Prop horizontal, plug and play. Measure Amps with your smartphone and smile (you want a 'Smart' version of the regulator, BT included in it).


Enough juice? Fit them more permanently. Hinged on poly rings. Cost 0 USD if you are handy.



Not enough amps / shade problems ? Lift some of them to the aft location on the radar pole you drafted.


Start simple, with few identical panels overreaching your wildest Wattage dreams, one regulator (100 / 30 in this case).


Skip small and odd panels, go for fewer big units. Identical ones, as this helps you mix, match and adjust.


Small odd panels are expensive and hassle to wire. Big identical units are cheap and easy to mix and match.


Your dodger is too small for sizeable panels. And the area on cabin ahead of the dodger needs be free for basking, walking, etc (e.g. when you work on the main).


STERN RAIL. Hinged. By best bet. ;-)



barnakiel

[Reefmagnet]

Here's something I'm experimenting with. A self supported panel hanging off a rail. The rail is there to support the panel and the panel is mounted with some rectangle section extrusions (salvaged from retired shopping centre display cabinets in this case). They hold in place using a U-bolt and a hardwood block that acts as a brake pad. An eye nut is used as an oversized wing nut to tighten or release the brake pressure for repositioning or folding. I'm considering replacing the u-bolt with back to back wooden blocks to increase brake force, but so far the idea seems to work.

[Pegu Club]

For electricity generation we have two Renogy 100 watt flexible panels on the Bimini with a MPPT controller for each panel, a 70 amp alternator on the Beta 16, all supplying amps to two firefly batteries that are monitored by a BALMAR smart gauge. We are about to start on our second year as full time cruisers, Xmas in George Town Bahamas this year. The big amp draws we have are the B&G Zeus 2, 7”, an Engle fridge, and a pelagic tiller pilot that will be hooked to our Monitor steering vane, a S/H vhf with AIS a receiver. The rest is charging phones, tablet, laptop, hand held vhf radios, etc etc. this set up has served us very well, no lack of amps thus far. Oh, and all LEDs through out the boat.

Fair winds,

[rgleason]

Wow, Barnakiel, sorry you lost that email, but your replacement is pretty clear,
I agree with your suggestion statement, forget the little panels and get 3 big ones.

I've taken some panels from Fly Solartech a small 50w with split cells so it is 17.6v (for the dodger) and another 140W at 22v (bimini), and tried to calculate the result of joining them in series, refering to "Mixing Solar Panels - Dos and Don'ts" - Example follows:

Port Side - Wired in Series

Panel 1
25.52 volts
5.97 amps
152.35 watts

Panel 2
17.60 volts
2.84 amps
49.98 watts

Sum Volts ------ 43.12 volts
Use lowest amps 2.84 amps
Output -----------122.46 watts

Just using bigger Panel 1 152.35 watts
Difference in watts ---------29.89 watts less
Reduction ------------------- 0.20
Joining the two panels which have different voltage and substantially different amperage results in a 20% reduction in output from the bigger panel.

Panels in Series should definitely have the amperage, and preferably the same voltage. Panels in series are more sensitive to output reductions with shadowing.

So the best way to wire these panels
#1-50w and #3 -160w
#2-50w and #4 -160w
is to wire them separately to Mppt or perhaps to wire #3 & #4 together in parallel series to a single controller.

So, in summary, Barnakiel's suggestion is probably the best approach.. Thanks!!


Pegu Club - I guess there is hope for a simple system.
Reefmagnet - I like that idea replacing the lifeline to have more area and makeing a nice simple panel connection. Thanks for posting.

[toddster8]

Ah, lost my mind (or at least my budget) and ordered up to 2x 100 Ah LiFePO4 batteries and a more efficient refrigeration unit. And an inverter. And already bought a more efficient radar. Wow, doubling the value of the boat again!

Previously had a collection of small odd panels.
2X 25 watt on the sea hood, 2x 50 watt on the dodger.

Just found new HQST 100 watt panels that are only 35.6 inches long. These are short enough to hinge off the existing sides of the pushpit, without building any new "structure." And only $90 each. Affordable enough to experiment with.

Could even add a couple more at that size, but if all works as per spec, this should cover my projected power budget. Unless I go buy some other damn fool gadget.

[rgleason]

From Barnakiel:

Victron SmartSolar MPPT 100/30 Charge Controller 226 Solar Panels - 3x12v 165w =495w 1.5 $/W, reg,cables,fuses included.

1500mm x 670 mm x 30mm, 11 kg each.
59 x 26.4 x 1.1 inches, 24.3 lbs
100 / 30 regulator (in series)
This places you at 500W @ USD 800 or thereabouts, reg, cables, fuses inclusive. Read 5 to 30 A into 12V batts any time the sun is shining.

What is the panel you are referring to?

[barnakiel]

Originally Posted by rgleason

From Barnakiel:


What is the panel you are referring to?

It is a generic panel. They all (virtually) seem to come from the same source somewhere in China. Same specs.



ebay, amazon, alibaba, etc.



Then the names label them and sell at margin.


b.

[barnakiel]

e.g.


these are all the same thing you can see from the specs that differ by less than 2% depending on what sticker applied.


Hope the image opens. Attached.


barnakiel

[drcat]

I'd look to the stern bimini as best location- limited shading by sail or boom, panel will provide shading if you want, largest area and out of way, won't need to walk on, should not catch the wind being horizontal, pretty close to battery bank I assume. You could put one 315-390 watt panel there with 2 alum square bars added to get you to 39" width. These panels would also extend past the length of bimini frame.
Panel - look at Altestore a 315w 20v mono panel for $187 65" x 39" or 390w 24v mono panel for $243 79" x 39"
MPPT solar charge controller- look at EPever Triron with remote and bat temp accessories, 40 amp battery charging output for $196 at amazon. This model could handle two 315 watt panels if you ever increased # panels. It would not be capable of using all the charging output power/amps of two 390 watt panels. EPever has been reviewed on youtube.
MC4 cables Pair (red and black) 20' or 30' $28 - $37 Amazon
50 amp switch/circuit breaker - to be insert in large cable between charge controller positive output and battery bank positive terminal $13 amazon
So for around $450 you can get 315 watts or $489 for 390 watts.

[rgleason]

barnakiel

Yes I found a bunch of those, mostly Spanish, similar to this one.
Thanks. Haven't found that available in the US, but this Canadian Solar one turned up and it got my imagination going, it is a Canadian Solar 305w monocrystalline for $198

Nominal Maximum Power (Pmax): 305 Watts
Optimum Operating Voltage (Vmp): 32.70 Volts
Optimum Operating Current (Imp): 9.33 Amps
Open Circuit Voltage (Voc): 39.90 Volts
Short Circuit Current (Isc): 9.91 Amps
Module Efficiency: 18.63%
Maximum System Voltage: 1000V (IEC) or 1000V (UL)
Module Fire Performance: Type1 (UL 1703) or Class C (IEC 61730)
Max Series Fuse Rating: 15 Amps
Application Classification: Class A
Power Tolerance: 0 / +5 W

That weighs 40 lbs

If my stern would support two of these on swing posts turned in one over the other and lashed together over the top of the outboard when moored or necessary, and then deployed when conditions are good, I'd have 610 watts in two panels! They could be deployed at any swing or rotation and might provide some shade at the helm at times.

Unfortunately, I need smaller and lighter panels, but using the same general idea. I notice your panel says it has 3 busbars, are there particular things in a solar panel that I should be looking for?

Would the Radar shadow be too much? It is at 9'-3" above the deck. Panels would be at about 4'-6" above the deck. Radar is 20" dia.

Thanks drcat - I'll check those out, just saw your post.

[barnakiel]

Originally Posted by Reefmagnet

Here's something I'm experimenting with. A self supported panel hanging off a rail. The rail is there to support the panel and the panel is mounted with some rectangle section extrusions (salvaged from retired shopping centre display cabinets in this case). They hold in place using a U-bolt and a hardwood block that acts as a brake pad. An eye nut is used as an oversized wing nut to tighten or release the brake pressure for repositioning or folding. I'm considering replacing the u-bolt with back to back wooden blocks to increase brake force, but so far the idea seems to work.

Yep. This is one quick and simple mount method.


Warning - at times it makes sense to add a provisional batten (if only a wooden latch) to run from one corner to the deck, at angle.


The point is the there is a lot of twisting power on the joint when the wind busts or when the boat suddenly moves on the wave and they sometimes let the panel drop and hit the stanchion or else flip upwards and hit whoever stands there.


So if you see any tendency to twist, either turn the screw tighter (on time)! or add such a simple plastic or wooden batten to 'lock' any unwanted movement.


Cheers,
b.

[rgleason]

I suppose one or two of these SunPower would break the bank.
Solar Panels | SunPower

[barnakiel]

Originally Posted by rgleason

barnakiel

Yes I found a bunch of those, mostly Spanish, similar to this one.
Thanks. Haven't found that available in the US, but this Canadian Solar one turned up and it got my imagination going, it is a Canadian Solar 305w monocrystalline for $198
That weighs 40 lbs

If my stern would support two of these on swing posts turned in one over the other and lashed together over the top of the outboard when moored or necessary, and then deployed when conditions are good, I'd have 610 watts in two panels! They could be deployed at any swing or rotation and might provide some shade at the helm at times.

Unfortunately, I need smaller and lighter panels, but using the same general idea. I notice your panel says it has 3 busbars, are there particular things in a solar panel that I should be looking for?

Would the Radar shadow be too much? It is at 9'-3" above the deck. Panels would be at about 4'-6" above the deck. Radar is 20" dia.

Thanks drcat - I'll check those out, just saw your post.

R,


This brings you up to 610 eh? ;-) Yes, more solar ooomps is better. Keeps you covered on those days that the sun is way less than perfect.


Just mind the physical size - not to go into the area where you are fighting big heavy items and the deck is dancing under your feet!



If you take 2 as you say, this will ask for a beefier regulator too! $$



Here, the 100/50 model is nearly 2x the price of a 100/30 model. About USD 400 tax incl.


With cables and fuses you are edging now on USD 1000. And yes you are likely to get up to 8 A even on an otherwise mediocre day. Pretty impressive plant.


On a sunny day you will fill your banks in no time. How big is your house bank?



The 'three busbar' thing I am not recalling, do dig into this what they mean. The panel shows plain 2 cables much as the connector is different from the ones I use here.


The radar yes it WILL be trouble. Design the swinging arms so that you can swing one panel far outboard with the other swinged in or out of the radar shadow. Looks 100% achievable given your stern config.


Make sure the physical size of the panels matches your vision of what it is like to handle these. You can cut a mock in plain cardboard to get the feeling of the area (packing boxes of big LED TV screens at every city skip - big, flat, hard cardboard, prime free and recyclable mock material.). The weight ... you must just imagine it. ;-)



b.

[Elzaar]

I feel late to the party, but if it helps ...

I installed two Solbian 134'sh watt panels to my bimini and two 70 watt panels to my semi-hard dodge (king starboard top) two years ago. Where I live on the west coast is about the same latitude as Boston, but having lived both places I can say Boston gets more sunlight - especially in Winter.

I will try to add more later and some pics, but quick observations:

I went with four semi-flexible panels. All rated at or about 24 volts, all at least 20 percent efficiency, all with their own mppt controller. I have a meter that tracks performance in real time, so I have spent some time checking it in various situations.

Any close shading on a panel greatly reduces performance. I turned my radar 180 degrees to try to keep one of my 130 panels clear, but when any of it or even the backstay is catching the panel, performance drops by at least 50 percent. Unless you isolate the panel somehow from others with diodes, it would reduce every other panel on the same mppt. Spend the $100 for individual mppt's.

My larger, more expensive, bimini panels are frequently outperformed by my Dodger mounted panels. Some of this may be because I lash my boom off to the side to keep them in direct sun, some may be because they have a slight angle to them where the bimini mounted ones are close to flat, and some of it may be the slight radar shading, I dont know. They are all made with Sunpower cells. The Dodger mounted panels came from Firstmate Marine in Anacortes, Washington so you may want to check out their website (I cant get the link to paste). I'm not affiliated, but the owner is another New England guy and very helpful.

One thing I did with all the panels was mount them on top of polycarbonate channeled sheets like greenhouses use. This thread is a good reminder I wanted to check them to see if they actually reduce heat build up. What I can say is after two years in the northwest with winds regularly over 70 mph, the solar panels and polycarbonate Is all still in place and functioning.

I cant say from personal experience, but from what I've read, the ability to adjust the panel angle throughout the day is very beneficial. The same place I mentioned above sells a pole kit you might find useful that puts a rigid panel on top and allows unlimited adjustment. It can also mount a outboard davit. Your boat has plenty of room for one if you decide not to go the bimini route.

My boat runs a frig, small freezer, and the usual stuff, all LED lights. No a.c. or anything crazy. My calculated amp needs are about 105 amps per day on the hook. My set up produces at least that much probably 90 percent of the time. On really good days my batteries are topped off by noon. Having said that, I just added a projector so I'm debating ways of adding one more panel .. okay, one crazy thing.

Feel free to PM me. I am at the boat just about every day.