How to connect 18-150watt panel and six 75 watt panel?

JAYMIN

I have total 24 BIPV panel out of that 18 panel has power 150 watt and 6 panel has power 75 WATT can i make two string in each string have 9-150watt panel and 6- 75 watt panel.? voltage will reduce in each string due to 75 watt panel?

vtmaps

We need to know the specs on each of the panels.   --vtMaps

JAYMIN

vtmaps said:

We need to know the specs on each of the panels.   --vtMaps

150 watt panel : size : 1125*982 mm , cell : 48 , Voc : 28.7v , Vmp : 23.5v , Isc : 7.02A , Imp: 6.38A 

75 watt panel : Size : 1125*982 mm , cell : 24 , Voc : 14.5v , Vmp : 11.75v , Isc : 3.5A , Imp: 2.19A 

vtmaps

The number for the 75 watt panel are not correct.  Vmp X Imp = watts.  11.75 volts X 2.19 amps = 25.7 watts.

--vtMaps

JAYMIN

vtmaps said:

The number for the 75 watt panel are not correct.  Vmp X Imp = watts.  11.75 volts X 2.19 amps = 25.7 watts.

--vtMaps

sorry dear 75 watt panel has Imp : 6.38A

BB.

What battery bank voltage are you trying to run? (12/24/48 volt or something else)?

What solar charge controller are you (trying) to run? Is it an MPPT (maximum power point tracking) or PWM (Plus width modulation)?

Those panels do not map well to 12 or 24 volt battery banks (typically Vmp~18 volts for 12 volt bank and Vmp~36 volts for a 24 volt battery bank). With MPPT type charge controller, you can go >>Vmp nominal for your battery banks (MPPT controllers will take "high voltage/low current" and efficiently down convert to "low voltage/high current" needed to charge the battery bank (within capabilities of the MPPT controller's ratings).

-Bill

JAYMIN

BB. said:

What battery bank voltage are you trying to run? (12/24/48 volt or something else)?

What solar charge controller are you (trying) to run? Is it an MPPT (maximum power point tracking) or PWM (Plus width modulation)?

Those panels do not map well to 12 or 24 volt battery banks (typically Vmp~18 volts for 12 volt bank and Vmp~36 volts for a 24 volt battery bank). With MPPT type charge controller, you can go >>Vmp nominal for your battery banks (MPPT controllers will take "high voltage/low current" and efficiently down convert to "low voltage/high current" needed to charge the battery bank (within capabilities of the MPPT controller's ratings).

-Bill

NOP DEAR IT IS ON GRID PROJECT.

BB.

Jaymin,

What are the input requirements of your GT Inverter (voltage range, maximum current, watts, etc.)?

-Bill

JAYMIN

min. start voltage : 110V , ax. input voltage : 600V , num of MPPT : 1 , MPPT VOLTAGE RANGE : 100-520V , MAX. INPUT CURRENT : 11A

BB.

It looks like you would put 9x 150 Watt panels in series, 2x parallel strings.

150 watt panel : size : 1125*982 mm , cell : 48 , Voc : 28.7v , Vmp : 23.5v , Isc : 7.02A , Imp: 6.38A
75 watt panel : Size : 1125*982 mm , cell : 24 , Voc : 14.5v , Vmp : 11.75v , Isc : xxxA Imp: 6.38A 

The ratings for the panels still do not look correct (the 75 watt panels especially). Anyway, your array would have:

• Vmp-array = 23.5 volts * 9 panels in series = 211.5 volts nominal (standard temperature)
  
• Voc-array = 28.7 volts * 9 panels in series = 258.3 volts (standard temperature)
• Imp-array = 6.38 Amps * 2 parallel strings = 12.76 amps nominal

So--You already exceed the 11 amp max input current--It would then appear that this array will give you a maximum array wattage of:

• 211.5 volts * 11 amps max input current = 2,321 Watt DC array (standard test conditions)
• 2,321 Watts * 0.77 panel and controller deratings = 1,787 Watt AC output (typical peak in warm/sunny weather)
  

If your GT inverter is capable of higher wattage (and it manages the 11 amp "clipping" of array current), you could can put 3x 75 Watt panels in series with the 9x 150 Watt panels (~317.25 Vmp-array with 9+3 panels in series). That would give more solar power to the GT inverter (if it is capable of the larger/higher Wattage array).

• 211.5 volts + (3 * 11.75 volts Vmp) = 246.75 volts Vmp-array (9+3 panels)
  
• 246.75 volts Vmp-array * 11 Amps * 0.77 panel+controller derating = 2,090 Watt typical peak output
  

-Bill

Note: fixed calculator errors above.

JAYMIN

BB. said:

It looks like you would put 9x 150 Watt panels in series, 2x parallel strings.

150 watt panel : size : 1125*982 mm , cell : 48 , Voc : 28.7v , Vmp : 23.5v , Isc : 7.02A , Imp: 6.38A
75 watt panel : Size : 1125*982 mm , cell : 24 , Voc : 14.5v , Vmp : 11.75v , Isc : xxxA Imp: 6.38A 

The ratings for the panels still do not look correct (the 75 watt panels especially). Anyway, your array would have:

• Vmp-array = 23.5 volts * 9 panels in series = 211.5 volts nominal (standard temperature)
  
• Voc-array = 28.7 volts * 9 panels in series = 258.3 volts (standard temperature)
• Imp-array = 6.38 Amps * 2 parallel strings = 12.76 amps nominal

So--You already exceed the 11 amp max input current--It would then appear that this array will give you a maximum array wattage of:

• 211.5 volts * 11 amps max input current = 2,321 Watt DC array (standard test conditions)
• 2,321 Watts * 0.77 panel and controller deratings = 1,787 Watt AC output (typical peak in warm/sunny weather)
  

If your GT inverter is capable of higher wattage (and it manages the 11 amp "clipping" of array current), you could can put 3x 75 Watt panels in series with the 9x 150 Watt panels (~317.25 Vmp-array with 9+3 panels in series). That would give more solar power to the GT inverter (if it is capable of the larger/higher Wattage array).

• 317.25 volts Vmp-array * 11 Amps * 0.77 panel+controller derating = 2,687 typical peak output
  

-Bill

thanks dear but i did not understand how how we can put 9 , 150watt panel in series with 3 , 75watt panel , beacause 150watt panel has Vmp 23.5 and 75 watt panel has Vmp : 11.75V so if we can connect then total Vmp = 9*23.5+11.75*3 = 246.75V and you said (~317.25 Vmp-array with 9+3 panels in series).

BB.

Jaymin,

Oops... Made a calculator error (did the 3x on the added panels twice)--Fixed original post in bold.

-Bill

JAYMIN

BB. said:

Jaymin,

Oops... Made a calculator error (did the 3x on the added panels twice)--Fixed original post in bold.

-Bill

thanks dear bill and i am confuse about the total power output as we will connect two string in parallel ( each string has 9 150watt panel + 3 75watt panel) one string (with 12 panel) will give out put of 2090 watt then two string must give 2090*2 = 4180 watt 

BUT TOTAL POWER SHOULD BE 150watt*18panel + 75*6 = 3150WATT 

AND ONCE AGAIN THANKS BILL

BB.

Jaymin,

First, your GT inverter has an 11 Amp maximum input current (vs the ~2x 7.02 amps of each strings Imp). so you lost ~3 amps there.

And next Vmp is temperature dependent. Solar panels are typically rated under mfg. test conditions (flash testing--"full sun" for a few seconds "sun" lamp, cell temperature ~25C). In real life, solar panels get hot in full sun and Vmp fall--Roughly to ~81% of "std" Vmp on a nice spring day (very hot weather, Vmp can fall more. In very cold climates, below freezing, Vmp can be higher than STD test condition rating).

lastly, roughly 95% efficiency of the GT inverter...

• Total "derating" 0.81 panel temp * 0.95 GT inverter efficiency = 0.77 = 77% "typical power output" of "panel STD Rating (typical maximum on average spring day at noon time).

Does this make sense (It is midnight here--I may not be making much sense right now).

-Bill

JAYMIN

BB. said:

Jaymin,

First, your GT inverter has an 11 Amp maximum input current (vs the ~2x 7.02 amps of each strings Imp). so you lost ~3 amps there.

And next Vmp is temperature dependent. Solar panels are typically rated under mfg. test conditions (flash testing--"full sun" for a few seconds "sun" lamp, cell temperature ~25C). In real life, solar panels get hot in full sun and Vmp fall--Roughly to ~81% of "std" Vmp on a nice spring day (very hot weather, Vmp can fall more. In very cold climates, below freezing, Vmp can be higher than STD test condition rating).

lastly, roughly 95% efficiency of the GT inverter...

• Total "derating" 0.81 panel temp * 0.95 GT inverter efficiency = 0.77 = 77% "typical power output" of "panel STD Rating (typical maximum on average spring day at noon time).

Does this make sense (It is midnight here--I may not be making much sense right now).

-Bill

thank you very much bill and sry if i disturb you.

BB.

My pleasure Jaymin. If I was not awake, I would not be reading the forum.

-Bill