solar..parallel Vs series parallel

[Sea Dog]

6 hours ago, TheBiscuits said:

Both.  The waterproof changeover switch is in a box in the cabin.

Since its waterproof, you could keep it down your weed hatch to save a bit of space.

[jenevers]

On 22/01/2019 at 18:28, Jen-in-Wellies said:

Series-Parallel wiring. How I'd do it.

The isolation switch between the panels and the controller is important on some models to prevent damage to the controller that can be caused if the batteries are disconnected and they are still getting solar in. Not essential, but easier than pulling the correct plugs out of the panels. Fuse between the controller and the batteries to safeguard the wiring if the controller develops a fault. Wire direct to batteries, bypassing main isolator switch.

 

Jenny

 

 

As a matter of interest, am I right in thinking that the voltage and amperage going to the MPPT will be doubled by going series/parallel?

[rusty69]

 

I originally connected our 4 panels series-parallel,but later connected 3 in series through one controller and a separate one through another controller. 

Edited February 3, 2019 by rusty69
Still can't spell parrallell after all these years

[jenevers]

13 minutes ago, rusty69 said:

 

I originally connected our 4 panels series-parallel,but later connected 3 in series through one controller and a separate one through another controller. 

But why?

 

[Tony Brooks]

23 minutes ago, jenevers said:

As a matter of interest, am I right in thinking that the voltage and amperage going to the MPPT will be doubled by going series/parallel?

Series connection will give the same current (Amps) as a single panel but the voltage will be the sum of all the panel voltage (assuming all the same size).

 

Parallel connection will give the voltage of a single panel but the current will be the sum of all the panels current.

 

Take four panels in series parallel as the diagram above. Each series string will provide the current of one of its panels but sum of the voltages. When the strings are paralleled the current will be the sum of the currents from each string and the voltage will be the voltage of a single string.

 

 

[rusty69]

1 minute ago, jenevers said:

But why?

 

One of the panels was being shaded, so pulling the other one down, so i split it off. 

[jenevers]

3 minutes ago, Tony Brooks said:

Series connection will give the same current (Amps) as a single panel but the voltage will be the sum of all the panel voltage (assuming all the same size).

 

Parallel connection will give the voltage of a single panel but the current will be the sum of all the panels current.

 

Take four panels in series parallel as the diagram above. Each series string will provide the current of one of its panels but sum of the voltages. When the strings are paralleled the current will be the sum of the currents from each string and the voltage will be the voltage of a single string.

 

 

Thanks Tony, excellent as usual.? So the answer to my question is "Yes"... No? ??

[Tony Brooks]

1 minute ago, jenevers said:

Thanks Tony, excellent as usual.? So the answer to my question is "Yes"... No? ??

The question needs better defining to get a  yes - no answer. Working from the diagram of four panels. When compared with a SINGLE panel the voltage of the array will be double that of a single panel and so will the current. So given the qualification about the digram and also all panels being the same size the answer is yes.

[jenevers]

9 minutes ago, rusty69 said:

One of the panels was being shaded, so pulling the other one down, so i split it off. 

I see. So you are moored up in the same place for long periods I suppose.

1 minute ago, Tony Brooks said:

The question needs better defining to get a  yes - no answer. Working from the diagram of four panels. When compared with a SINGLE panel the voltage of the array will be double that of a single panel and so will the current. So given the qualification about the digram and also all panels being the same size the answer is yes.

?

[rusty69]

5 minutes ago, jenevers said:

see. So you are moored up in the same place for long periods I suppose.

When on my home mooring, yes. I need to invest in a chainsaw. 

[Scholar Gypsy]

On the Yes/no point, to a first approximation the power output from the panels is the same whether in series or in parallel - volts x amps. So either (say) 18V and 10A in parallel (180W) or 36V and 5A in series (180W). The controller then converts that to something that suits the batteries....

 

Of course the whole point of this thread is that in practice the power is different in the two configurations, due to the vagaries of how the controller works and whether the level of sun/shade is the same everywhere.

[jenevers]

7 minutes ago, Scholar Gypsy said:

On the Yes/no point, to a first approximation the power output from the panels is the same whether in series or in parallel - volts x amps. So either (say) 18V and 10A in parallel (180W) or 36V and 5A in series (180W). The controller then converts that to something that suits the batteries....

 

Of course the whole point of this thread is that in practice the power is different in the two configurations, due to the vagaries of how the controller works and whether the level of sun/shade is the same everywhere.

It wasn't actually a Yes/no point?.

 

I was saying "So the answer to my Question is Yes..................no?(as in "Is it not?")

Can't put inflections into a text type message?

[Scholar Gypsy]

28 minutes ago, jenevers said:

It wasn't actually a Yes/no point?.

 

I was saying "So the answer to my Question is Yes..................no?(as in "Is it not?")

Can't put inflections into a text type message?

Indeed!  With apologies for pedantry, it's still not a very well posed question. "As a matter of interest, am I right in thinking that the voltage and amperage going to the MPPT will be doubled by going series/parallel?"

 

I think you mean "As a matter of interest, am I right in thinking that the voltage and amperage going to the MPPT will be doubled and halved respectively, by going  to series from parallel?" [and vice versa].  My answer to that question is "Yes".

[Johny London]

Rather than trying to have a waterproof switch, or a permanent wiring one way or the other, why not bring all the solar panel wiring back to the controller (ie a pair in series, two wires, another pair in series, two wires), then a suitable switch just before the controller.

The only downside is you'll need as much cable as doing it 2 x parallel in series, and as much voltage rating in your controller etc as if doing it all series. But then that's it - and you can easily experiment on borderline days, and see what's happening on the controller display.

 

On a slightly different track, I have decided that it is definitely worth having a simple tilt mechanism on the panels. I'v seen the results of a panel being tilted to the sun on a winters day and it is worthwhile. My next pair I will be mounting flat, but with pins in the four brackets, so any two pins can be removed and the panel lifting from one side and hinging on the other sides pins. It still gives a really low profile in flat mode (unlike those centre mounted pivots), just needs a prop up brace for the panel.

[jenevers]

On 03/02/2019 at 12:23, Scholar Gypsy said:

Indeed!  With apologies for pedantry, it's still not a very well posed question. "As a matter of interest, am I right in thinking that the voltage and amperage going to the MPPT will be doubled by going series/parallel?"

 

I think you mean "As a matter of interest, am I right in thinking that the voltage and amperage going to the MPPT will be doubled and halved respectively, by going  to series from parallel?" [and vice versa].  My answer to that question is "Yes".

Now I’m confused because I thought series/parallel meant both voltage AND amperage are doubled as per the diagram.?

[Scholar Gypsy]

1 minute ago, jenevers said:

Now I’m confused because I thought series/parallel meant both voltage AND amperage are doubled as per the diagram.?

Ah yes. So compared with one single panel, the arrangement of 4 in your original diagram will deliver double the current, and double the voltage. So 4 times the power (2x2 not 2+2).

[Tony Brooks]

14 hours ago, jenevers said:

Now I’m confused because I thought series/parallel meant both voltage AND amperage are doubled as per the diagram.?

But you are still leaving important pieces of the question out. You seem to assume every on who reads it knows what you mean and they know the question relates to the four panel set-up as illustrated. The vital part is when four panels connected in series parallel are compared with a single panel.

 

As long as you mean four panels connected in series parallel when compared with a single panel then your answer is YES.

[jenevers]

1 hour ago, Tony Brooks said:

But you are still leaving important pieces of the question out. You seem to assume every on who reads it knows what you mean and they know the question relates to the four panel set-up as illustrated. The vital part is when four panels connected in series parallel are compared with a single panel.

 

As long as you mean four panels connected in series parallel when compared with a single panel then your answer is YES.

I did?. It's difficult being absolutely precise on a forum. I was referring specifically to the illustration kindly supplied by Jen-in-Wellies, for my particular setup.

Edited February 5, 2019 by jenevers