My solar system

senangsekali · Nov 9, 2017

I now have 4 100W flexible panel on top of my bimini. They are attached with zippers and flaps over the zippers to protect them, so they will not come off. I have the panels wired in series to make 48v and 5.6 amps. Mppt controller. I have a pic of the remote panel attached. Does anyone have any comments or suggestions weather to go all series or parallel or combination of both. I have four 6volt trojan L16's la wired serial/parallel for my house and one 4d for my starter.
Thank ia

john61ct · Nov 9, 2017

Each MPPT is different, just pick a clear sky day and be ready to test different combo's for highest total output, into a battery at 50%, ideally all within an hour around noon.

senangsekali · Nov 9, 2017

Yes i never had the chance to so that yet. I suppose i only have a few options with what i have. I have trace mttp controller.

AusCan · Nov 10, 2017

An MTTP controller goes through a test cycle to determine the most efficient setup. This often takes a few minutes.
When doing comparison tests, give it time to stabilize before measuring output.

Ex Sailor · Nov 10, 2017

senangsekali said:
I now have 4 100W flexible panel on top of my bimini. They are attached with zippers and flaps over the zippers to protect them, so they will not come off. I have the panels wired in series to make 48v and 5.6 amps. Mppt controller. I have a pic of the remote panel attached. Does anyone have any comments or suggestions weather to go all series or parallel or combination of both. I have four 6volt trojan L16's la wired serial/parallel for my house and one 4d for my starter.
Thank ia
View attachment 70196

The way I see it ... In Parallel @ 12 VDC: On an optimum day, you may get 24 - 26 +/- Amps and this will drop off substantially as you lose sunlight. ( I assume that you have the wiring @ at least 30 A / 10 Ga. )
In Series @ 48 VDC +/- : On an optimum day, you may get 5.6 - 6.6 +/- Amps but you will get this longer even if you lose sunlight ( until cut off. )
It's a " you can't get something for nothing " type of thing ......

On my 3 @ 140W rigid panels ( now in series ) I'm seriously considering rewiring to parallel for next year. FB

Bob Cofer · Nov 10, 2017

My 2 x 300w panels are in series. This is a typical day.

Ex Sailor · Nov 10, 2017

Bob Cofer said:
My 2 x 300w panels are in series. This is a typical day.

View attachment 70204 View attachment 70204

Hey Bob, Very impressive Amps ! and @ 36 V and 20 A give / take ea. they may as well be in series. In my case, I chose the 12 V panels just in case I wanted them in parallel. FB

DavidM · Nov 10, 2017

Bob Cofer said:
My 2 x 300w panels are in series. This is a typical day.

Bob:

Just for fun, I converted the input and output of your controller to watts: 314 and 317 respectively. Hmm, a little first law violation?

David

boathealer · Nov 10, 2017

djmarchand said:
Bob:

Just for fun, I converted the input and output of your controller to watts: 314 and 317 respectively. Hmm, a little first law violation?

David

??

Tom.B · Nov 10, 2017

I came for a model of the sun, the planets, and the moons. I am leaving disappointed.

Xsbank · Nov 10, 2017

Series is better if you get shading.

healhustler · Nov 10, 2017

You can get a lot of opinions on this, but YouTube has some nice demo’s on both that might be helpful to check out.

senangsekali · Nov 10, 2017

Thanks i will have to watch somr videos

Paul Swanson · Nov 11, 2017

Xsbank said:
Series is better if you get shading.

Isn't that just backwards? With series panels, if one is shaded and does not produce then the whole string id out. Think old-style X-mas tree bulbs.

senangsekali · Nov 11, 2017

Im not sure if it works like that, but what do i know. Learn something everyday.

Nightsky · Nov 11, 2017

According to solar panel expert, I copied and pasted their response regarding whether to series or parallel 2 panels where some shading is unavoidable...

"So, this kind of shows you, that if you do have some partial shading, and it’s on only one of the panels at a time, so say you’ve got a chimney that you really have no control over, or if it’s on a sailboat, and you’ve got the mast that is kind of important, if you’ve got partial shading that’s going to be changing, it’s better to wire them in parallel to give the parallel path for the non-shaded panel. Ideally, and I know I say this a lot, ideally each panel should have its own charge controller, that way you will get absolute maximum performance, but if it’s not an option, wiring in parallel with partial shading is your better solution."

senangsekali · Nov 25, 2017

my solar panels on the bimini.

john61ct · Nov 25, 2017

Nightsky said:
According to solar panel expert, I copied and pasted their response regarding whether to series or parallel 2 panels where some shading is unavoidable...

"So, this kind of shows you, that if you do have some partial shading, and it’s on only one of the panels at a time, so say you’ve got a chimney that you really have no control over, or if it’s on a sailboat, and you’ve got the mast that is kind of important, if you’ve got partial shading that’s going to be changing, it’s better to wire them in parallel to give the parallel path for the non-shaded panel. Ideally, and I know I say this a lot, ideally each panel should have its own charge controller, that way you will get absolute maximum performance, but if it’s not an option, wiring in parallel with partial shading is your better solution."

Yes.

And if you standardize on Victron 75/15 at under $100 each, match your panels to maximize the SC output, you can get 1:1 ratio at **lower** cost than multiple panels per larger SC.

40-50Voc, maximum 65
200-240W, up to 300 if you get a super deal and not compromising maximum watts over your available square area.

Double those watts for 24V banks

Such overpanelling will increase *average* watts output when conditions are less than optimal.

Spottsville · Dec 15, 2017

senangsekali said:
View attachment 70697my solar panels on the bimini.

What brand flexible panels did you use? Supplier?

senangsekali · Dec 15, 2017

I used a local supplier who sells them. Im not sure of the manufacturer. But seem to good quality and work very well on sunny days

foggysail · Jan 2, 2018

healhustler said:
You can get a lot of opinions on this, but YouTube has some nice demo’s on both that might be helpful to check out.

I am not sure which videos you refer to. I did watch some videos that gave one the understanding that series connections are inferior to parallel. The (it was a girl) tester showed differences in wattages when she shaded one panel with a rag.

DO NOT BELIEVE THAT TEST!!!!!!!!!!

Shadows DO NOT cover the panel like rags can. There is alway illumance present even during shading. And sure there will be some degradation but no where near what the so called knowageable tester proclaimed.

I have 4 each 32 Vmp panels that I operate with two in parallel and those two connected in series with another two in parallel. If your controller can handle the higher open circuit maximum voltages that a series connection can provide, it offers a big advantage of smaller wire sizes along with smaller wire losses.

twistedtree · Jan 2, 2018

foggysail said:
I am not sure which videos you refer to. I did watch some videos that gave one the understanding that series connections are inferior to parallel. The (it was a girl) tester showed differences in wattages when she shaded one panel with a rag.

DO NOT BELIEVE THAT TEST!!!!!!!!!!

Shadows DO NOT cover the panel like rags can. There is alway illumance present even during shading. And sure there will be some degradation but no where near what the so called knowageable tester proclaimed.

I have 4 each 32 Vmp panels that I operate with two in parallel and those two connected in series with another two in parallel. If your controller can handle the higher open circuit maximum voltages that a series connection can provide, it offers a big advantage of smaller wire sizes along with smaller wire losses.

I agree that was a bad test in the YouTube video. Different MPPT chargers respond at different rates to shading. All they really showed was that the Outback MPPT charger responds slowly. It was a big disservice to the subject.

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