Starting a new system in the deep Jungle of South America

[sdold]

If my calculations are wrong, please let me know. 4x100w panels will do 400w / 12v = 33.33amps. How can I use 1 x20amp controller?

I bought 30 amps controllers now, but I am not sure if I can use 4 panels with it. Whats the suggestion?

A 100W panel will only produce about 5A if connected to a 12V battery. So 5A x 4 panels is about 20A.

If you check the nameplate of the panel, it'll tell you that the voltage and current at maximum power (100W) is roughly 18V and 5A. It'll also tell you that the short circuit current (Isc) will be around 5.5A, which gives you a rough idea of the maximum current the panel can possibly produce.

If the panel is connected to a battery directly or through a PWM controller, the panel voltage will be "pulled down" to about 12V and the current will be about 5A, or roughly 60W. What this means is that, with a PWM controller that really just operates as an on/off switch to the battery, the panel is really a 60W panel, not 100W. To get 100W out of it you'd need to use an MPPT controller and wire them in series. An MPPT controller allows the panels to "sit" at whatever voltage creates the most power, in this case about 18V/panel.

[josuemolina2000]

A 100W panel will only produce about 5A if connected to a 12V battery. So 5A x 4 panels is about 20A.

If you check the nameplate of the panel, it'll tell you that the voltage and current at maximum power (100W) is roughly 18V and 5A. It'll also tell you that the short circuit current (Isc) will be around 5.5A, which gives you a rough idea of the maximum current the panel can possibly produce.

If the panel is connected to a battery directly or through a PWM controller, the panel voltage will be "pulled down" to about 12V and the current will be about 5A, or roughly 60W. What this means is that, with a PWM controller that really just operates as an on/off switch to the battery, the panel is really a 60W panel, not 100W. To get 100W out of it you'd need to use an MPPT controller and wire them in series. An MPPT controller allows the panels to "sit" at whatever voltage creates the most power, in this case about 18V/panel.

My panels tags says:

Isofoton I-100/12

Max power: 100 +- 10% Wp
Short Circuit Current: 6.54a
Open Circuit Voltage: 21.6v
Max Power Current: 5.74a
Max power Voltage: 17.4v

Max System Voltage 760v Safety Class II

So, how many can I connect with a 30a PWM charge controller? Thanks in advance

[sdold]

My panels tags says:

Isofoton I-100/12

Max power: 100 +- 10% Wp
Short Circuit Current: 6.54a
Open Circuit Voltage: 21.6v
Max Power Current: 5.74a
Max power Voltage: 17.4v

Max System Voltage 760v Safety Class II

So, how many can I connect with a 30a PWM charge controller? Thanks in advance

Four panels might be a good maximum for a 30A PWM controller. I'm curious what others think, but here's my logic: Guessing at the current from each panel being around 6A at 12V, 4 panels in parallel would be about 24A and 5 panels would be around 30. I don't feel good about running a PWM controller near its current limit because I recently received a couple of Xantrex/Schneider C12 controllers that had been running for years with a single 12V panel at around 6A or a little over, but then failed shortly after the addition of a second panel was added, doubling the charge current. The folks at Schneider said the likely cause of failure was running at maximum (or slightly above) in the intense heat of the summer we just had. We replaced them with 30A units.

Not sure why someone would suggest a 20A controller for four panels, maybe it is OK and there is something I'm missing.

Steve

[NEOH]

Hello,
I just wanted to double check if what I am doing will work.

10 panels of 100w and 2 30a charge controllers. Working as 2 Sets of separate solar panels arrays 5 panels per charge controller:
connected to the batteries, reaching around 55amps max of charge

2 6volts 215ah batteries

1 pure sine wave sunforce 1000w peak 2000w

8avg cable for batteries and inverter

Will this work?

My needs:
I just need to turn on my fridge (180w) sometimes during daylight, a max of 6 hours a day.
4 LED lights for 3 or 4 hours. MAX.

Extra, but not necessary:
I also have a deep freezer that draws(240w MAX).
Will my inverter run it too? How long?

Thank you guys in advance.

Why have you abandoned the "unlimited (free?) supply" of 20 Amp Charge Controllers?
2 x 100 Watt PV Panels per Array / Charge controller = 16 amps each
Install all five (5) PV Arrays ( all 10 panels ) pointed in multiple directions, in an "overlapping" arc ...
Array #1 pointed with 2 hour Eastern bias = +30 Degrees
Array #2 pointed with 1 hour Eastern bias = +15 Degrees
Array #3 pointed straight up (+/-)
Array #4 pointed with 1 hour Western bias = - 15 Degrees
Array #5 pointed with 2 hour Western bias = - 30 Degrees
producing a broad steady constant power stream for your Fridge during the day and more hours to recharge the battery.
Connect all five charge controllers to the to the 12 Volt battery bank.

Now you suggest (WHY?)
500 Watts = 5 x 100 Watts Panels
41 Amps = 500 Watts / 12 Volts
But you have a 30 Amp Charge Controller?

If you must use a 30 Amp Controller then consider ...
300 Watts = 3 x 100 Watts Panels ( in parallel ? )
25 Amps = 300 Watts / 12 Volts
You have a 30 Amp Charge Controller.

What are the RATINGS of your 100 Watt Panels?
Voc =
Vmp =
Imp =
Isc =

What is the Make & Model of your 20 Amp Charge Controller?
Is it PWM or MPPT ?

What is the Make & Model of your 30 Amp Charge Controller?
Is it PWM or MPPT ?

[josuemolina2000]

Why have you abandoned the "unlimited (free?) supply" of 20 Amp Charge Controllers?
2 x 100 Watt PV Panels per Array / Charge controller = 16 amps each
Install all five (5) PV Arrays ( all 10 panels ) pointed in multiple directions, in an "overlapping" arc ...
Array #1 pointed with 2 hour Eastern bias = +30 Degrees
Array #2 pointed with 1 hour Eastern bias = +15 Degrees
Array #3 pointed straight up (+/-)
Array #4 pointed with 1 hour Western bias = - 15 Degrees
Array #5 pointed with 2 hour Western bias = - 30 Degrees
producing a broad steady constant power stream for your Fridge during the day and more hours to recharge the battery.
Connect all five charge controllers to the to the 12 Volt battery bank.

I really like this idea. The panels are like 8 years old, same with controllers. People dont want them anymore, because they dont want to have to buy batteries. so giving them away for nothing.

Now you suggest (WHY?)
500 Watts = 5 x 100 Watts Panels
41 Amps = 500 Watts / 12 Volts
But you have a 30 Amp Charge Controller?

Because someone commented that 4 panels can be connected with the 20a CC. But I asked because my calculations were the same that you just typed.

If you must use a 30 Amp Controller then consider ...
300 Watts = 3 x 100 Watts Panels ( in parallel ? )
25 Amps = 300 Watts / 12 Volts
You have a 30 Amp Charge Controller.

What are the RATINGS of your 100 Watt Panels?
Voc =
Vmp =
Imp =
Isc =

My panels tags says:

Isofoton I-100/12

Max power: 100 +- 10% Wp
Short Circuit Current: 6.54a
Open Circuit Voltage: 21.6v
Max Power Current: 5.74a
Max power Voltage: 17.4v

Max System Voltage 760v Safety Class II

What is the Make & Model of your 20 Amp Charge Controller?
Is it PWM or MPPT ?

8 years old phocos 20a PWM CC

What is the Make & Model of your 30 Amp Charge Controller?
Is it PWM or MPPT ?

New 30A PWM controllers that are inexpensive like this ones but bought on Ebay.
https://www.amazon.com/ALLPOWERS-Cha...FP691G9GM5V4WJ

[NEOH]

================================================== ==========================
2 x 100 Watt PV Panels per Array / Charge controller
Install all five (5) PV Arrays ( all 10 panels ) pointed in multiple directions, in an "overlapping" arc

Array #1 pointed with 2 hour Eastern bias = +30 Degrees
Array #2 pointed with 1 hour Eastern bias = +15 Degrees
Array #3 pointed straight up (+/-)
Array #4 pointed with 1 hour Western bias = - 15 Degrees
Array #5 pointed with 2 hour Western bias = - 30 Degrees
Producing a broad steady constant power stream for your Fridge during the day and more hours to recharge the battery.
Connect all five charge controllers to the to the 12 Volt battery bank.
================================================== ====

The above design means you buy very little equipment = VERY LOW BUDGET
You really do need a battery !!!
You replied that the Charge Controller is PWM, not MPPT
PWM is not as efficient as MPPT.
This costs you nothing to connect and try

How many Continuous Hours of 100% sunlight will actually shine on your panels?
What time does the sun rise above the trees in the east?
What time does the sun set below the trees in the east?

Max Power Point = 17.4 Volts
So, connect two ( or three ) PV Panels in parallel to each charge controller, not in series.

PWM mode
=========
12.0 Volts x 5.74 Amps x 2 = 140 Watts per charge controller
14.8 Volts x 5.74 Amps x 2 = 169 Watts per charge controller
NOTES:
Watts harvested is lower and varies with battery voltage
Do you really care since the PV Panels and CC's are free?
You could even add a third PV Panel in parallel for more energy = more amps.

MPPT Mode
==========
17.4 Volts x 5.74 Amps x 2 = 199 Watts
Notes:
Watts harvested is higher and is independent of battery voltage, = increased cost.

Estimate at Solar Noon, 5 arrays of 2 PV Panels in parallel per Charge Controller, battery at 13 volts
Array #1 - 9.9 Amps = 5.74 Amps x 2 x 86%
Array #2 - 11.0 Amps = 5.74 Amps x 2 x 96%
Array #3 - 11.5 Amps = 5.74 Amps x 2 x 100%
Array #4 - 11.0 Amps = 5.74 Amps x 2 x 96%
Array #5 - 9.9 Amps = 5.74 Amps x 2 x 86%
===============================
Total = 53 Amps x 80% = ~42 Amps in the real world x 13 Volts = 560 Watts harvested

Big bus bar at the battery connection.

If you need more energy in the morning, then add another PV Array + CC and point those PV Panels directly towards the morning sun = +45 Degrees East?
If you need more energy in the evening, then add another Array + CC and point those PV Panels directly towards the evening sun.= - 45 Degrees West?
The sun is weaker in the morning and the the evening

An alternate design ...
Array #1 = East +45 degrees ( and maybe 3 panels in parallel ? )
Array #2 = East +30 degrees
Array #3 = East +15 degrees
Array #4 = Up
Array #5 = West -15 degrees
Array #6 = West -30 degrees
Array #7 = West -45 degrees ( and maybe 3 panels in parallel ? )

See how they have ROWS OF PANELS = ARRAYS pointing East, Up and West in this photo ...

https://www.solarworld-usa.com/~/media/www/images/photo-gallery/projects/commercial/plantronics-1.jpg

Will your freezer be shut and off all night?

[AzRoute66]

See how they have ROWS OF PANELS = ARRAYS pointing East, Up and West in this photo ...

Great photo. Love the concept for off-grid.

[josuemolina2000]

================================================== ==========================
PWM mode
=========
12.0 Volts x 5.74 Amps x 2 = 140 Watts per charge controller
14.8 Volts x 5.74 Amps x 2 = 169 Watts per charge controller


An alternate design ...
Array #1 = East +45 degrees ( and maybe 3 panels in parallel ? )
Array #2 = East +30 degrees
Array #3 = East +15 degrees
Array #4 = Up
Array #5 = West -15 degrees
Array #6 = West -30 degrees
Array #7 = West -45 degrees ( and maybe 3 panels in parallel ? )

See how they have ROWS OF PANELS = ARRAYS pointing East, Up and West in this photo ...
https://www.solarworld-usa.com/~/med...ntronics-1.jpg

Will your freezer be shut and off all night?

Thanks for your answer.
Everything will be shut down after 10pm. And will not be running everyday, because power comes back. Maybe a week in a row max.

I got 2 6v Batt for cell towers of 215Ah.

I think because of my budget, time and space(Live in a hill, not a lot of space nearby) I will be doing the following:

Array #1 = with a: 30a PWM
East +30 degrees 2 panels
East +15 degrees 2 panels


Array #2 = with a 30A PWM
Up 4 panels

Array #3 = with a: 30A PWM
West -15 degrees 2 panels
West -30 degrees 2 panels


TOTAL of: 12 panels and 3 30A PWM CC and 12V 214ah battery bank. 1200 peak 2400 pure sine wave.


ALL in parallel of course.

4 panels per array should give from:
276W to 340W MAX.

If I add 1 more, 5 panels per array should give from:
345W to 425W MAX. Do you really think they could reach that high, even when they are so old?

Thanks

[NEOH]

Thanks for your answer.
Everything will be shut down after 10pm. And will not be running everyday, because power comes back. Maybe a week in a row max.

I got 2 6v Batt for cell towers of 215Ah.

I think because of my budget, time and space(Live in a hill, not a lot of space nearby) I will be doing the following:

Array #1 = with a: 30a PWM
East +30 degrees 2 panels
East +15 degrees 2 panels


Array #2 = with a 30A PWM
Up 4 panels

Array #3 = with a: 30A PWM
West -15 degrees 2 panels
West -30 degrees 2 panels

TOTAL of: 12 panels and 3 30A PWM CC and 12V 214ah battery bank. 1200 peak 2400 pure sine wave.

ALL in parallel of course.

4 panels per array should give from:
276W to 340W MAX.

If I add 1 more, 5 panels per array should give from:
345W to 425W MAX. Do you really think they could reach that high, even when they are so old?

Thanks

OK, sounds like a plan.

I do not like Cell Tower batteries.
They are typically float type batteries and not rated for many Deep Discharges.
But that 215 AH battery will stabilize your Charge Controllers and the DC-to-AC Inverter which is all you really need, for now.

I have read, about 1/2% to 3% degradation per year on average for PV Panels, some more, some less.

Why not test all of the PV Panels before proceeding?
Under full sun ...
Measure the Voc = Voltage Open Circuit = 21.6 Volts
Measure the Isc = Amps Short Circuit= 6.54 Amps ( Special 10 Amp setting on multimeter )
Let us know what you measure.

Note that I had degraded the Net Amps = 80% x Theoretical Amps, to account for all losses.
You will have to deal with HEAT - which lowers the PV Voltage.
But the PWM Charge Controllers are already doing that, so ... Hmmm???

Do you have plans for a copper bus bar at the +/- battery terminals for all of these AMPS?

[josuemolina2000]

OK, sounds like a plan.

I do not like Cell Tower batteries.
They are typically float type batteries and not rated for many Deep Discharges.
But that 215 AH battery will stabilize your Charge Controllers and the DC-to-AC Inverter which is all you really need, for now.


Do you have plans for a copper bus bar at the +/- battery terminals for all of these AMPS?

Actually, I am not sure if they are for cell phone tower, they say they are for different applications, included solar.
Sorry is in Spanish
http://www.bateriasdacar.com/EnglishDacar/img/espetecnica/IMP-SOLAR-002.pdf

I will do the test some time next week.

And, no, I have no plans for a copper bus bar. I got cable #6 for my 2 6v batteries in series.

Oh, and BTW, I am in Ecuador, South America. So that pretty much tells you the sun inclination here.

[bcroe]

================================================== ==========================
2 x 100 Watt PV Panels per Array / Charge controller
Install all five (5) PV Arrays ( all 10 panels ) pointed in multiple directions, in an "overlapping" arc

Array #1 pointed with 2 hour Eastern bias = +30 Degrees
Array #2 pointed with 1 hour Eastern bias = +15 Degrees
Array #3 pointed straight up (+/-)
Array #4 pointed with 1 hour Western bias = - 15 Degrees
Array #5 pointed with 2 hour Western bias = - 30 Degrees
Producing a broad steady constant power stream for your Fridge during the day and more hours to recharge the battery.
Connect all five charge controllers to the to the 12 Volt battery bank.
================================================== ====

The above design means you buy very little equipment = VERY LOW BUDGET
You really do need a battery !!!
You replied that the Charge Controller is PWM, not MPPT
PWM is not as efficient as MPPT.
This costs you nothing to connect and try

How many Continuous Hours of 100% sunlight will actually shine on your panels?
What time does the sun rise above the trees in the east?
What time does the sun set below the trees in the east?

Max Power Point = 17.4 Volts
So, connect two ( or three ) PV Panels in parallel to each charge controller, not in series.

PWM mode
=========
12.0 Volts x 5.74 Amps x 2 = 140 Watts per charge controller
14.8 Volts x 5.74 Amps x 2 = 169 Watts per charge controller
NOTES:
Watts harvested is lower and varies with battery voltage
Do you really care since the PV Panels and CC's are free?
You could even add a third PV Panel in parallel for more energy = more amps.

MPPT Mode
==========
17.4 Volts x 5.74 Amps x 2 = 199 Watts
Notes:
Watts harvested is higher and is independent of battery voltage, = increased cost.

Estimate at Solar Noon, 5 arrays of 2 PV Panels in parallel per Charge Controller, battery at 13 volts
Array #1 - 9.9 Amps = 5.74 Amps x 2 x 86%
Array #2 - 11.0 Amps = 5.74 Amps x 2 x 96%
Array #3 - 11.5 Amps = 5.74 Amps x 2 x 100%
Array #4 - 11.0 Amps = 5.74 Amps x 2 x 96%
Array #5 - 9.9 Amps = 5.74 Amps x 2 x 86%
===============================
Total = 53 Amps x 80% = ~42 Amps in the real world x 13 Volts = 560 Watts harvested

Big bus bar at the battery connection.

If you need more energy in the morning, then add another PV Array + CC and point those PV Panels directly towards the morning sun = +45 Degrees East?
If you need more energy in the evening, then add another Array + CC and point those PV Panels directly towards the evening sun.= - 45 Degrees West?
The sun is weaker in the morning and the the evening

An alternate design ...
Array #1 = East +45 degrees ( and maybe 3 panels in parallel ? )
Array #2 = East +30 degrees
Array #3 = East +15 degrees
Array #4 = Up
Array #5 = West -15 degrees
Array #6 = West -30 degrees
Array #7 = West -45 degrees ( and maybe 3 panels in parallel ? )

See how they have ROWS OF PANELS = ARRAYS pointing East, Up and West in this photo ...

Thats cool, wonder what the latitude is, and what the hourly power curve looks like? What is their cloud situation? Bruce Roe

[NEOH]

Great photo. Love the concept for off-grid.

Pointing all of the PV Panels due south minimizes the amount time to recharge the battery bank.
Lead Acid Batteries need time, lots of time, too much time ... Bulk => Absorb => Float

This graph ...

http://3.bp.blogspot.com/-viil26ejaR4/Uhc1gFieroI/AAAAAAAAAF0/Meqy2RyiKIw/s1600/East_West_Array_Watts.jpg

made me think about adding East - West pointing:
1) Generate more PV Power earlier in the day - to switch from the Battery Bank to PV power, as soon a possible in the morning.
2) Generate more PV Power later in the day, to delay switching to the battery bank in the evening.

Thus, giving the battery bank more time to recharge.
The challenge is get the "Orange Curve" in the graph, as wide as possible, and as high as possible.
The "Blue Curve" is less desirable for off-grid.

[NEOH]

Actually, I am not sure if they are for cell phone tower, they say they are for different applications, included solar.
Sorry is in Spanish
http://www.bateriasdacar.com/EnglishDacar/img/espetecnica/IMP-SOLAR-002.pdf

I will do the test some time next week.

And, no, I have no plans for a copper bus bar. I got cable #6 for my 2 6v batteries in series.

Oh, and BTW, I am in Ecuador, South America. So that pretty much tells you the sun inclination here.

Your inclination is straight up.

The PDF,

"... Stationary Monoblock Electromagnet Free (EMEL) batteries with Lead - Silver alloy provide a minimum water consumption compared to lead - Antimony. Are the most suitable for the uses of Power Backup (Telecom, UPS) and Photovoltaic due to its long life and to its exceptional operating capacity in slow loading and unloading regimes. The main advantages of our Monoblock accumulator is the ease of handling and / or replacement of the same in in case of failure, as well as a greater reserve capacity of electrolyte, which translates into the need for low maintenance. Monoblocks, for their part, occupy very little space, install quickly and at the same time are very robust and compact. As for the difference between stationary batteries type OPzS and our monoblock is that our can be easily configured in modular benches and can reach the required capacities without have OPzS type cells that are very heavy and difficult to install. ..."

Whenever I see "Telecom" or "UPS", I think Float forever and fewer deep cycles.
Let us know how it works for you, because that is what matters.

[josuemolina2000]

Your inclination is straight up.

Sorry about this question, it might be dumb.. Are you saying I dont need to tilt them at all?

[NEOH]

I am at 42 Degrees North Latitude, so I have a huge fixed tilt pointing south.

Enter you County & City ...
http://solarelectricityhandbook.com/...alculator.html
and it will display your optimum Monthly Tilt

For you ...
The sun is mostly directly overhead ( straight up )
Dec worst case South = 22 Degrees tilt
Jun worst case North = 24 Degrees tilt

So, if you had a Fixed Ground Mount the tilt would be fixed at +/-0 Degrees?

Seasonal Tilt ...

http://www.solarpaneltilt.com/