Solar Panels - Series or Parallel ?

[TeddyDiver]

Originally Posted by socaldmax

Then why even post those results if they were not representative and without mentioning the time of day?

What is your normal max. output?

It was Eder's panel test you quoted, not mine..

[socaldmax]

Originally Posted by TeddyDiver

It was Eder's panel test you quoted, not mine..

I see that now, just wondering why you replied to my post to him.

It's 12pm here, Pacific time.

I don't see anything in his post or his profile that indicates that it's 7 or 8 am where he is. How did you determine that's what time he did the test?

[TeddyDiver]

Originally Posted by socaldmax

I see that now, just wondering why you replied to my post to him.

It's 12pm here, Pacific time.

I don't see anything in his post or his profile that indicates that it's 7 or 8 am where he is. How did you determine that's what time he did the test?

He said four hours to wait for noon..

[sparrowhawk1]

Originally Posted by SailFastTri

Same here. I have long wiring runs and have seen a 25% (or more) improvement in overall charge performance by changing from parallel to series. In longer wire runs, higher voltage is less affected by voltage drop for equal wire diameter.

The panels are 12v and I have 4 on each side of my boat. They are wired as series-pairs, and the two pairs are connected in parallel back to the controller. Both sides are in parallel. The MPPT controller sees ~37v open voltage.

Well I think that's what it comes down to, if you have a multi hull or a cabin in the woods with minimal shading, series makes more sense. But if throughout the day several of your panels are going to be shaded parallel makes more sense. PS what got this thread rolling again was a video showing two panels hooked up in series and parallel and how both of them were knocked out in series but only one of them was knocked out in parallel

[socaldmax]

Originally Posted by TeddyDiver

He said four hours to wait for noon..

Thank you for pointing that out! I completely missed the last sentence of his post!

[robert sailor]

Lots of talk about shading and while no matter the setup you will get some shading from time to time BUT it boggles my mind to look at some cruisers setups. Solar panels with a wind generator mounted on one side or often both sides a guarantee of constant shading. Its pretty clear that in many of these installations the owner used zero common sense and it seems as if ascetics was the main motivation.

[Mike OReilly]

Originally Posted by robert sailor

Lots of talk about shading and while no matter the setup you will get some shading from time to time BUT it boggles my mind to look at some cruisers setups. Solar panels with a wind generator mounted on one side or often both sides a guarantee of constant shading. Its pretty clear that in many of these installations the owner used zero common sense and it seems as if ascetics was the main motivation.

I guess I resemble this comment Robert .

On our double-ender, with our long boom, wide mast and heavy shrouds, I have few options for panel mounting that won't be shaded sometime. I suppose I could set up wings off the cockpit, but that feels unwise from a seaworthy perspective. Otherwise I'm stuck with mid-line panels, and a windmill that does solid duty much of the time.

It's not ascetics. It's physical reality.

[Eder]

Originally Posted by socaldmax

Did you notice how they were getting 15 A out of 240w of panels and 16A out of 280w of panels?

With 400w, you should be getting north of 20 A, at least. Either all of your panels are producing less than they should, or possibly the one panel you were shading wasn't producing anything to begin with. The 2nd scenario would more likely explain your results.

Think about it. A fully shade panel should produce nothing. If shading it didn't drop your output, then logically, it wasn't producing anything to begin with.

I am getting 20 amps right now...the panels are affected by angle of sun,cloud, etc. When I posted earlier the sun was fairly low still so output was low as well.

[sparrowhawk1]

Originally Posted by Mike OReilly

I guess I resemble this comment Robert .

On our double-ender, with our long boom, wide mast and heavy shrouds, I have few options for panel mounting that won't be shaded sometime. I suppose I could set up wings off the cockpit, but that feels unwise from a seaworthy perspective. Otherwise I'm stuck with mid-line panels, and a windmill that does solid duty much of the time.

It's not ascetics. It's physical reality.

Yes physical reality ,the panels may be shaded by the wind generator, but the bottom line is not just how much but when the electricity is produced. The wind generator may cut out one quarter of your solar production if the shade is wrong but during cloudy days and at night it makes up for it. And not point out the obvious: during a windy day!

[socaldmax]

Originally Posted by Eder

I am getting 20 amps right now...the panels are affected by angle of sun,cloud, etc. When I posted earlier the sun was fairly low still so output was low as well.

Yes, my mistake, I missed the last sentence of your post.

[Kokanee]

I wouldn't read too much into that video. The amperage figures they were reading may not be representative of long term output. The Outback MPPT controller they were using takes time to perform a "sweep" and adjust itself to compensate for shadows. The sweep interval is adjustable between 1 & 15 minutes. It appeared that they were taking current readings immediately after making changes.

[svtrio]

Mainesail, Curious to know what controllers you are using, and any others that you would recommend as being fast and suitable for the marine environment.


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[Maine Sail]

Originally Posted by svtrio

Mainesail, Curious to know what controllers you are using, and any others that you would recommend as being fast and suitable for the marine environment.


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It depends upon what the installation is. I use some Genasun controllers for small arrays and they are very fast tracking but lack temp sensing, other than ambient (need to be very close to the batteries), and they lack the ability to be programed in the field. I also use some of the Victron controllers where I need programming capability on smaller systems and then for larger systems I often use Morningstar TriStar MPPT controllers. I have also used Midnite (the KID is nice but is a very awkward form factor) and a few others and tested & decided against a number of off-shore controllers none of which are as fast as the Genasun or Morningstar for moving targets like boats.

I have a couple of customers with newer Outback FM series and have been impressed by the speed at which they track but they need to be set up carefully and auto start needs to be set to 0 for continuous tracking. My main frustration with them is that they really need an array voltage of at least 12V above absorption to operate as efficiently as they should. On boats with parallel strings this can become problematic..

Option wise the Outbacks are loaded, (so is the Morningstar) it will do everything but wash the dishes. I suspect perhaps Outback has changed the way in which it tracks, speed wise, in newer models. I do know on one customers boat I made it track faster by programming auto start (I think it was called auto start, I could be wrong on that too) to off or 0. They are very impressive units, feature wise, but I am not a huge fan of having fans etc. inside an MPPT controller or the fact that it needs a PV of 12V beyond battery volts to operate at peak efficiency. Course if you are in the class to have enough PV for a 60A controller the load of the fan etc. is minuscule.

[MikeFergie]

I put a frame out the back of my binimi on my leopard cat. I put 2 x sun power 345w panels off the back and pull my boom on anchor to the side so I get max sun.

The panels are wired each to their own Victron blue solar 100/30 Mppt controller and both wired to the buzz bars for the batteries. I have 3 x 210amphour gel batteries which I put in new 2 months ago. I have a Victron bmv700 with shunt to manage my system and I have usb cables coming from everything to a pc to read what I want from the system.

I go out every weekend and my boat sits on a three point anchorage during the week but the fridge freezer stays on 24/7.

So far what is interesting is that I average 243k/w amphours per month per panel. This means the panels are pushing in over 500k/w amp hours per month. Considering that when I am out I use on average 120amphours per night that's still a lot coming in.
During the week my bulk charging is usually 2-3 hours and then to the rest but usually the cycle is always full every day

I expect once I live full time on the boat and start using my washing machine and water maker I might need to get another panel.

I have a Victron 1200/12 inverter which runs everything I need so far. This includes my espresso machine which by far draws the most amphours I have seen on my boat 185 amphours when it's making expresso coffee.

Rgards
MikeF


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[tanglewood]

Originally Posted by MikeFergie

I put a frame out the back of my binimi on my leopard cat. I put 2 x sun power 345w panels off the back and pull my boom on anchor to the side so I get max sun.

The panels are wired each to their own Victron blue solar 100/30 Mppt controller and both wired to the buzz bars for the batteries. I have 3 x 210amphour gel batteries which I put in new 2 months ago. I have a Victron bmv700 with shunt to manage my system and I have usb cables coming from everything to a pc to read what I want from the system.

I go out every weekend and my boat sits on a three point anchorage during the week but the fridge freezer stays on 24/7.

So far what is interesting is that I average 243k/w amphours per month per panel. This means the panels are pushing in over 500k/w amp hours per month. Considering that when I am out I use on average 120amphours per night that's still a lot coming in.
During the week my bulk charging is usually 2-3 hours and then to the rest but usually the cycle is always full every day

I expect once I live full time on the boat and start using my washing machine and water maker I might need to get another panel.

I have a Victron 1200/12 inverter which runs everything I need so far. This includes my espresso machine which by far draws the most amphours I have seen on my boat 185 amphours when it's making expresso coffee.

Rgards
MikeF


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I think you've got your units mixed up. Energy put into or taken out of your batteries would be measured in either killo watt hours (kwh), or amp hours (ah). You can convert between the two if you know your battery voltage. 100 ah taken from a 12V battery would be 1200 watt-hours, or 1.2 kwh.

And your esspresso machine is probably drawing 185 amp from your batteries when running. Sounds like a 12V system at that amperage.