RichardS
N/A
Errrr .... as I said, with non-shaded panels in series you will get more of the power produced at the panels actually through to the batteries because of the lower transmission losses.
Richard
Solar panels. In series or parallel?
- Thread starter Denek
- Start date
Richard
cherod
N/A
is that all , i thot that with given that both systems are working properly there might be some advantages or otherwise in the systems ,, no ??Errrr .... as I said, with non-shaded panels in series you will get more of the power produced at the panels actually through to the batteries because of the lower transmission losses.
Richard
RichardS
N/A
As I said at the start, without details about the panels and the controller it's impossible to be very specific but, as a general statement, with matched panels and no shading and a suitable MPPT controller then it will always be better to put the panels in series.
Richard
coopec
N/A
I'd be interested to read that article. Is this the article you are referring to?
Fitting solar panels - Practical Boat Owner
https://keyassets.timeincuk.net/ins...s/19/2014/12/berry-solar-panels-for-web-2.pdf
RobbieW
Well-Known Member
That's the how I installed my panels, 4x50 rather than 2x100. Connected as diagonal pairs into an MPPT controller. The higher voltage compensates for a longish cable run from stern to centre on a centre cockpit boat with the battery bank under a saloon seat
Denek
Well-Known Member
But I would think on a boat this is virtually impossible to achieve. I don’t currently have an MPPT controller, I have the other type. The panel is fitted to my hatch garage so gets varying amounts of shade. As a temporary fix I will probably just have an additional panel to leave out when moored or at anchor until the end of the season and then fit a couple permanently over the winter ready for next year when we plan extended cruising. Should have been this year but due to COVID we pushed it back. I will read and watch the presentation suggested when I get a moment but sounds like it could be worth buying an MPPT controller
MarkCX
Well-Known Member
A decent MPPT controller makes a significant difference. Be wary of cheap, unbranded controllers claiming to be MPPT, some people report that they aren’t MPPT.
Graham_Wright
Well-Known Member
Benefitting from a declared lack of knowledge, I installed a rotary switch to allow me to select the port or starboard panels individually, and also to allow them to be connected in series and parallel. The only difference noted while playing with the switch is that, in series, the combined output reduces when one panel is shaded. In parallel the output is still reduced but by a lesser amount (as you would expect).
Both panels are 50 watts and I have so far been disappointed to see no more than 4 amps at output even yesterday during the intense insolation although this is slightly increased after the Victron controller.
The body however, browned nicely.?
Both panels are 50 watts and I have so far been disappointed to see no more than 4 amps at output even yesterday during the intense insolation although this is slightly increased after the Victron controller.
The body however, browned nicely.?
noelex
Well-Known Member
The wiring configuration that generally produces the highest amount of total energy on a yacht is, from best to worse:
One controller per panel
Parallel connection
Series connection
Unfortunately if ranked for ease of installation, or cost, the order is generally the opposite of the above:
Series connection
Parallel connection
One controller per panel
Parallel connection is the most common and is a reasonable compromise between the above conflicting requirements. For this type of connection the panels do not have to be identical. They can have a very different wattage, but if using a MPPT controller the Vmp needs to close, preferably the same, but within 0.5v is generally deemed acceptable.
The panel requirements for series connection are quite different.
The controller also needs to be large enough to be able to handle the current. Add together the wattage of the panels and divide this by the battery voltage. If this is less than the current capacity of the controller everything is fine. In some cases you can settle for slightly less, but there are added precautions if this is the case.
One controller per panel
Parallel connection
Series connection
Unfortunately if ranked for ease of installation, or cost, the order is generally the opposite of the above:
Series connection
Parallel connection
One controller per panel
Parallel connection is the most common and is a reasonable compromise between the above conflicting requirements. For this type of connection the panels do not have to be identical. They can have a very different wattage, but if using a MPPT controller the Vmp needs to close, preferably the same, but within 0.5v is generally deemed acceptable.
The panel requirements for series connection are quite different.
The controller also needs to be large enough to be able to handle the current. Add together the wattage of the panels and divide this by the battery voltage. If this is less than the current capacity of the controller everything is fine. In some cases you can settle for slightly less, but there are added precautions if this is the case.
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MarkCX
Well-Known Member
What was the state of charge of your batteries? It might be possible they could not take more than 4 amps.
noelex
Well-Known Member
A good test of a solar system is that at least occasionally under very good conditions, when the loads are high, or the batteries reasonably discharged, the peak output should be very close to rated output of the panels. This indicates everything is working correctly.
If this is not the case you should try and trace the problem.
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Graham376
Well-Known Member
I have 2 x 160w panels on gantry and Victron MPPT. Found mast shadow virtually killed output when series connected but only reduces performance when parallel. In theory, series will give better output but my 320w panels occasionally peak at over 300w in parallel.
Interesting video here -
Interesting video here -
Graham376
Well-Known Member
One problem I've had with the panels is a bad contact on one of the MC4 connectors, done it again today so the panels were only outputting 50%. Will cut the MC4s out and hard wire, just need to find a couple of 15a Shottky diodes (hopefully locally) with wires not pcb connectors.
noelex
Well-Known Member
If installing individual controllers, or solar panels with a solar controller and parallel connection, additional diodes are generally counterproductive. You can estimate the net loss/gain, but this is reasonably complex.
The exceptions are if you want to connect the solar panel directly without a controller, the very small number of controllers that do not shut down the solar panel at night, or in areas where snow cover, or indoor storage can cause some anomaly’s. These are rare exceptions.
With series connection of panels additional bypass diodes are worth considering.
The exceptions are if you want to connect the solar panel directly without a controller, the very small number of controllers that do not shut down the solar panel at night, or in areas where snow cover, or indoor storage can cause some anomaly’s. These are rare exceptions.
With series connection of panels additional bypass diodes are worth considering.
sailaboutvic
Well-Known Member
We played about with two 100w panels connected to a Victron MPPT to see how much different there was in parallel and series if part of one panel was shaded .
We was surprised to find there was little if any different .
Can anyone explain this ?
We was surprised to find there was little if any different .
Can anyone explain this ?
TernVI
Well-Known Member
How much power were you getting?
What were the voltages?
Either the inefficiencies of parallel and series were about the same, or that was all the power the Victron wanted.
Possibly your panels have a lot of internal series strings in parallel, so the shaded panel was not badly affected?
noelex
Well-Known Member
There are not large differences beteen the power extracted from series and parallel connection. In some situations one can do significantly better, but on average the differences are not huge.
On a yacht, on average, parallel connection does better. This method of connection requires larger guage cables which is more expensive and more difficult, but for many (not all) installations the trouble and cost is worthwhile.
sailaboutvic
Well-Known Member
Time and time again we read if there any shading best to have them in parallel but the test we did on my mate boat just out of curiosity more then any thing else show that not the case .
Maybe because we using a MPPT ?
On my boat I have 4x 100w panels connected to a Victron 100/20 in parallel , in theory the MPPT isn't quite big enough but I can't see my panels only on the odd day pushing out more then 20A , some. Will say I am wasting power , I don't quite see It that way ,
Having that extra panel means early part of the day and later in the day I getting the benefit from that panel it's only on the odd day and only for maybe a very few hours if that I losting out .
Maybe because we using a MPPT ?
On my boat I have 4x 100w panels connected to a Victron 100/20 in parallel , in theory the MPPT isn't quite big enough but I can't see my panels only on the odd day pushing out more then 20A , some. Will say I am wasting power , I don't quite see It that way ,
Having that extra panel means early part of the day and later in the day I getting the benefit from that panel it's only on the odd day and only for maybe a very few hours if that I losting out .
noelex
Well-Known Member
In some circumstances series connection can produce more, or at least as much power as parallel connection, but on average parallel connecction will be superior especially on a yacht where shadows are common.
You cannot use series connection (except in the rare case where the Vmp is below the battery voltage) without a MPPT controller.
Certainly you are wasting some power having an undersized controller. You are also relying on the controllers self protection mechanism to prevent damage.
These factors may or may not be significant. If starting from scratch a larger controller that is not limiting the solar panel output is generally sensible especially on a boat where space and windage concerns mean a larger solar array (to compensate for the loss created by the smaller controller) is not practical.
sailaboutvic
Well-Known Member
In normally circumstances I would agree with what you said and if the different in Amps was large enough to warrant a bigger control I would had invested in one .
But yes there always a but , my panels as listed as max power 5.18A
I take that to be in 100% best possible factor test no shading .
So thats just under a amp for my control .
although when the sun is above all panels I do see 20A for some time here in the Med
Which surprise me .
.72 of a amp even if it's reach isn't going to do any different to the MPPT or I wouldn't think so .
When fitting out this boat at the time we only had room for 2x100w why I brought the 100/20 MPPT since then I had some SS off the back when I fitted and extra two panel .
When weighing up if I should invest in a second MPPT to take the min of Amps the extra panels would put out if any I decide after talking to Victron that a small amount of extra current wouldn't do any damage to the control but it would restrict me to the max Amps the MPPT would allow.
it was spend another €200 on another MPPT or stick with what I have and possibly lost .72 Of a amp on a few days in the summer .
