Biggest Solar Panels...

[s/v Jedi]

Also, I am getting the idea that what you guys are doing is not partial shading but rather filtering, like using a Phifertex shade to cast a filtered light to the panel.

Partial shading is a hard 100% shadow on part of the panel, like the shade of the radar scanner or Starlink dish that is mounted over the panel.

Solar cells simply need sun exposure to output their rated voltage. This isn’t a matter of counting opinions, but scientific fact.

[skipgundlach]

Sideways to the discussion:

My Flying Pig new owner kept/will keep my 720W of Sunpower 2x360W, parallelled.

However, he ditched my 4x435AH Trojan 6vs for 3x 250-ish (dunno/recall exact but less AH than the FLAs) LiFePO4s.

I used to have to charge my batts all day long to assure they were full - and that was with the aid of a KISS windgen.

He's full before noon any day there's sun, with no change in amps used.

Cuz he can pump bulk-rate until full - no more of the slowdown with absorption and float.

Game changer. Wish I'd had that when I was cruising. He's NEVER run the Honda to charge in his 18 months of ownership.

YMMV and my apologies if this is a duplication.

[sailingharry]

So this is sort of a new topic, but so close to the meat of this thread, that I'm going to toss it in here.


I currently have on my arch 3 panels. 2 180W 25Voc panels, each going to a 75/15 Victron MPPT. Both were destroyed in an accident, and will be replaced by insurance (MUCH larger claim...). The third is a 100W panel that was constrained by space, but in the repair will be upgraded. The 100W feeds a Genasun 10A MPPT. End result would be 3 200W (technology advances), all at 25Voc, all going to 75/15 MPPT. I would be responsible for a 200W panel ($200) and a 75/15 MPPT ($125), or 600W for a cost to me of $325.


The alternative would be to replace all 3 panels with 2 365W panels. These are $184 each, so even though they are larger than the damaged panels, I think the insurance company would buy off on it. They are 40Voc, so an improvement. They are 10" longer, so I would have to go toe to toe with the aesthetic review committee (she hates helo pad solar arrays). I would get an additional 130w of solar, which would be nice. Since the voltage is higher, the current is actually lower, so all wires work. Unfortunately, I would need either a single 100/50 (yes, I know I really would need a 60A MPPT, but the 50 would work fine most of the time and only clip power at peak sunlight) for under $300, or two new controllers -- either 100/20 for $150 (significant limitations) or 100/30 for $215 (a bit less limiting), or 100/50 for questionable return on investment. So after insurance cost of $250 to $500 -- putting 2 panels in series with a marginal 100/50 for $250 is cheaper and very appealing. But I have to argue with the admiral.


So, the conundrum. 3 panels is 600W, vs 2 panels for 730W. I am reworking my arch to greatly reduce shading. The radar is moving to the mast. The wind generator will be going up for sale. The GPS/Irridium/AIS GPS are being move further out, and slightly lowered to eliminate shading. But, the AIS VHF antenna is still there, and my split backstay is just a couple inches forward of the array. Ignoring the increased power (it's only 130W, so not a lot) and ignoring the cost difference (its under $100), am I better served by 3 panels with dedicated MPPT controllers, 2 panels in series or parallel on a single MPPT, or (for a fairly significant cost increase) 2 panels with dedicated controllers?


2 panels on a single MPPT (either series or parallel) is really appealing, with significantly higher Voc and a bit more power, while saving money. I think I can win the size debate. But the 3 panels with dedicated MPPT seems to be better with the inevitable shading.


And with regard to shading. The AIS VHF antenna is too low for ideal function. I'm not going to put 2 VHF antennas on my masthead. So, is it worth running the AIS through a splitter to my masthead (recognizing that the VHF radio is used about 0.00001% of my normal operating time), mounting it on a spreader (is that really an OK solution?) or am I best keeping it on the arch and dealing with the shadow?


Oh so many decisions!

[RedneckRedcoat]

No way you could keep the wind generator , we have solar but the ability to make electric at night would be awesome !

[sailingharry]

Originally Posted by RedneckRedcoat

No way you could keep the wind generator , we have solar but the ability to make electric at night would be awesome !

I have dedicated amp meters on all of my renewable sources, so I can see the power they make. The D400 that I had performed very close to the published output curves -- meaning it very rarely made even 5A. Normally 1-2A (well, normally zero, but when it was turning it was 1-2), so typical daily output is well under 50Ah (rated output in 10kts of wind is under 2A, and I try and anchor in protected coves so rarely see 10kts at deck level -- at this moment I see 2-3kts at the masthead). It shaded my starboard 200W solar panel, mostly obliterating a potential 50Ah of solar. When a wind storm made it throw a blade and then bend the tail fin, I elected to remove it instead of repair it.


Note, I did see 50A once -- in the edge of a hurricane

[Pete7]

Originally Posted by sailingharry

The alternative would be to replace all 3 panels with 2 365W panels. These are $184 each, so even though they are larger than the damaged panels, I think the insurance company would buy off on it. They are 40Voc, so an improvement. They are 10" longer, so I would have to go toe to toe with the aesthetic review committee (she hates helo pad solar arrays). I would get an additional 130w of solar, which would be nice. Since the voltage is higher, the current is actually lower, so all wires work. Unfortunately, I would need either a single 100/50 (yes, I know I really would need a 60A MPPT, but the 50 would work fine most of the time and only clip power at peak sunlight) for under $300, or two new controllers -- either 100/20 for $150 (significant limitations) or 100/30 for $215 (a bit less limiting), or 100/50 for questionable return on investment. So after insurance cost of $250 to $500 -- putting 2 panels in series with a marginal 100/50 for $250 is cheaper and very appealing. But I have to argue with the admiral.


Oh so many decisions!

Very similar to our set up with 2 x 295 into a 100/50. Tell her it will power her hair dryer and run an induction hob for free, clean cooking without heating the interior of the yacht.

Pete

[RedneckRedcoat]

Originally Posted by sailingharry

I have dedicated amp meters on all of my renewable sources, so I can see the power they make. The D400 that I had performed very close to the published output curves -- meaning it very rarely made even 5A. Normally 1-2A (well, normally zero, but when it was turning it was 1-2), so typical daily output is well under 50Ah (rated output in 10kts of wind is under 2A, and I try and anchor in protected coves so rarely see 10kts at deck level -- at this moment I see 2-3kts at the masthead). It shaded my starboard 200W solar panel, mostly obliterating a potential 50Ah of solar. When a wind storm made it throw a blade and then bend the tail fin, I elected to remove it instead of repair it.


Note, I did see 50A once -- in the edge of a hurricane

Good to know

[CaptainRivet]

Originally Posted by Pete7

Very similar to our set up with 2 x 295 into a 100/50. Tell her it will power her hair dryer and run an induction hob for free, clean cooking without heating the interior of the yacht.

Pete

Pete knows the deal, hairdryer :-)

[noelex 77]

2 panels for 730w wired to two Victron 100/30 controllers would be the sweet spot, in my view. This will give you the highest output plus redundancy.

[CaptainRivet]

Originally Posted by sailingharry

So this is sort of a new topic, but so close to the meat of this thread, that I'm going to toss it in here.


I currently have on my arch 3 panels. 2 180W 25Voc panels, each going to a 75/15 Victron MPPT. Both were destroyed in an accident, and will be replaced by insurance (MUCH larger claim...). The third is a 100W panel that was constrained by space, but in the repair will be upgraded. The 100W feeds a Genasun 10A MPPT. End result would be 3 200W (technology advances), all at 25Voc, all going to 75/15 MPPT. I would be responsible for a 200W panel ($200) and a 75/15 MPPT ($125), or 600W for a cost to me of $325.


The alternative would be to replace all 3 panels with 2 365W panels. These are $184 each, so even though they are larger than the damaged panels, I think the insurance company would buy off on it. They are 40Voc, so an improvement. They are 10" longer, so I would have to go toe to toe with the aesthetic review committee (she hates helo pad solar arrays). I would get an additional 130w of solar, which would be nice. Since the voltage is higher, the current is actually lower, so all wires work. Unfortunately, I would need either a single 100/50 (yes, I know I really would need a 60A MPPT, but the 50 would work fine most of the time and only clip power at peak sunlight) for under $300, or two new controllers -- either 100/20 for $150 (significant limitations) or 100/30 for $215 (a bit less limiting), or 100/50 for questionable return on investment. So after insurance cost of $250 to $500 -- putting 2 panels in series with a marginal 100/50 for $250 is cheaper and very appealing. But I have to argue with the admiral.


So, the conundrum. 3 panels is 600W, vs 2 panels for 730W. I am reworking my arch to greatly reduce shading. The radar is moving to the mast. The wind generator will be going up for sale. The GPS/Irridium/AIS GPS are being move further out, and slightly lowered to eliminate shading. But, the AIS VHF antenna is still there, and my split backstay is just a couple inches forward of the array. Ignoring the increased power (it's only 130W, so not a lot) and ignoring the cost difference (its under $100), am I better served by 3 panels with dedicated MPPT controllers, 2 panels in series or parallel on a single MPPT, or (for a fairly significant cost increase) 2 panels with dedicated controllers?


2 panels on a single MPPT (either series or parallel) is really appealing, with significantly higher Voc and a bit more power, while saving money. I think I can win the size debate. But the 3 panels with dedicated MPPT seems to be better with the inevitable shading.


And with regard to shading. The AIS VHF antenna is too low for ideal function. I'm not going to put 2 VHF antennas on my masthead. So, is it worth running the AIS through a splitter to my masthead (recognizing that the VHF radio is used about 0.00001% of my normal operating time), mounting it on a spreader (is that really an OK solution?) or am I best keeping it on the arch and dealing with the shadow?


Oh so many decisions!

What size of 2 panel can you fit? 365W is normally 170cmx100cm.
I highly recommend bifacials with half cut cells on arch as
A) bifacial backside delivers up to +25% which I regularly see on mine. The panel is tated only front so 365W but i get regularly 440W from one.
B) half cut cells have a lower VOC but are less prone to shading.
C) bifacials work with diffusion light which water or eg white sails also reflect light. Also much less prone to shading.
I also highly recommend ro use 2x 50/100 MPPT, one per panel in your setup so you can harvest max from your solar. Saving here would be on the wrong spot and hardware constanly running in the limits die earlier. Saving 300-400$ will significantly reduce your harvest and if you take into account all the hassle you do to reduce shade and cost of the arch you wanna get max from it.
I have 3x365W Longli bifacials and they are a gamechanger. Other top1 tier manufacturer like sharp/LG, Maxteon,Sunpower... should have good and comparable bifacials in that size/wattage too if you cannot get Longli.
Only disadvantage of them they weight 1/3 more then convential panels as backside is out of glass too which is on the other side an advantage as they are more rigide what you want on an arch....
You can never have enough

[Statistical]

Originally Posted by sailingharry

And with regard to shading. The AIS VHF antenna is too low for ideal function. I'm not going to put 2 VHF antennas on my masthead. So, is it worth running the AIS through a splitter to my masthead (recognizing that the VHF radio is used about 0.00001% of my normal operating time), mounting it on a spreader (is that really an OK solution?) or am I best keeping it on the arch and dealing with the shadow?

Splitter works fine. The splitters are also passive on the VHF side meaning if the splitter fails or loses power you lose AIS but you still have VHF.

In fact for SOTDMA Class B (sometimes called class B+ or B "SO") using a normal VHF antenna not one optimized for "AIS" is better because long range transmission (message 27) is only done on AIS channels 3 & 4 (156.775 & 156.825 MHz) which are on the other end of the VHF spectrum.

[CaptainRivet]

Originally Posted by noelex 77

2 panels for 730w wired to two Victron 100/30 controllers would be the sweet spot, in my view. This will give you the highest output plus redundancy.

Don't cheap out here and bite the bullet getting 2x50/100MPPT smart, join them via VE direct network so they take care of each other.
If you use bifacials you see 880W and not 730W and would cap away sone significant harvest with 2x 30/100 plus they run in the limits often which reduces their lifespan.
That gives you highest output and real redudancy, if one breaks you cab wire 2 in series and get full output or 2 in parallel with small losses.
Spare going out for dinner twice and you have the upgrade cost covered.

[noelex 77]

Originally Posted by CaptainRivet

Don't cheap out here and bite the bullet getting 2x50/100MPPT smart, join them via VE direct network so they take care of each other.

Two of the 100/50 controllers would work fine, but I think it is overkill given the desire for cost constraints that are obvious from the post.

A 365w panel would only exceed the rating of the 100/30 controller if the panels were putting in their full rated wattage and the battery voltage was below 12.2v. This is unlikely. With around 60A output from the two panels the likelihood of the battery voltage dropping below 12.2v is low. It would take a very depleted battery bank and/or a high load and perfect solar conditions.

[CaptainRivet]

Originally Posted by noelex 77

Two of the 100/50 controllers would work fine, but I think it is overkill given the desire for cost constraints that are obvious from the post.

A 365w panel would only exceed the rating of the 100/30 controller if the panels were putting in their full rated wattage and the battery voltage was below 12.2v. This is unlikely. With around 60A output from the two panels the likelihood of the battery voltage dropping below 12.2v is low. It would take a very depleted battery bank and/or a high load and perfect solar conditions.

If there are serious cost constrains and we are talking about FLA battery bank then you are right, get 2x30/100...if you have lithium or plan to upgrade to it get the 2× 50/100.
I have 3x365W longli bifacial and i regularly see 440W per panel with LFP bank except winter times.

[s/v Jedi]

I always recommend redundancy but you also get that with a new but tested controller in a box in the parts bin aboard.

In this case I think I agree with others to get the two identical big panels with two controllers. If budget allows then go for the larger controller, which is also better when one controller fails, but take the smaller model otherwise.