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JA Solar 540W Production / efficiency


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Posted (edited)

Hi,

Just wondering what should production be on 8 x JA Solar 540W panels (1 series string), facing north on a normal pitch tile roof. Twenty (20) meters of 6mm solar cable used between panel & inverter.

The time now is 12:10 (27 April 2022 Eastern Cape, SA, Coastal). It is sunny day, no clouds. herewith my results:

292.5 Volts

11.2 Amps

3.27 KW Exporting to grid

Does the above results look right?

Inverter 8KW SunSynk

Edited by abeetude
Added a bit more detail

8 answers to this question

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  • 1
Posted
4 hours ago, abeetude said:

Just wondering what should production be on 8 x 540W panels (1 series string), facing north on a normal pitch tile roof.

The time now is 12:10. It is sunny day day, no clouds. herewith my results:

292.5 Volts

11.2 Amps

3.27 KW

Does the above results look right?

8 x 540 = 4320 W nominal. Generally, you'd expect about 75-80% of nominal power under real-world, panels hot conditions. So that's 3.24 - 3.46 kW. So you're at the low end, not too bad for this time of year.

So yes, the above looks about right.

  • 0
Posted
36 minutes ago, abeetude said:

Hi,

Just wondering what should production be on 8 x 540W panels (1 series string), facing north on a normal pitch tile roof.

The time now is 12:10. It is sunny day day, no clouds. herewith my results:

292.5 Volts

11.2 Amps

3.27 KW

Does the above results look right?

Inverter 8KW SunSynk

It will depend on you house load, try increase the load and you should see your PV production should increase accordingly.

 

  • 0
Posted

What make panels are they?

How long are the cables to your panels

Are those the maximum numbers that you have on record? 

 8 x 540W = 4320W 

Assuming that they are JA Solar 540W specs are 12.97A & VMP 41.64V

If those specs are correct for your panels, you should max out at about 333v at the panels with no cables. 

That would mean that you are loosing about 12.5% from the cables from the panels assuming that the 292.5V is the max you are getting. 

I have two strings, one with quite a long cable run to get to them +- 15mtr, I loose about 10%, for comparison, I have another string that runs about 8mtr of cable and I loose about 8% from that string. 

Voltages vary slightly during the day but not nearly as much as the amperage that comes from the panels. 

Really depends on the make/specs of the panels you have.

 

 

 

 

 

 

  • 0
Posted
2 minutes ago, Antonio de Sa said:

It will depend on you house load, try increase the load and you should see your PV production should increase accordingly.

 

100% correct @Antonio de Sa but only when the battery is fully charged/you are hitting the max amount of power you can put into the battery and you are not feeding back into the grid, the inverter has nothing to do with the extra power so the MPPT's will increase resistance to the panels which will reduce the amperage coming from the panels. This however does not affect the panel voltage which will remain constant. 

The formulae for the power the panels are generating is Power = Volts X Amps so if you are loosing volts due to cable loss it will reduce the amount of power you get from the panels. 

  • 0
Posted
1 hour ago, abeetude said:

Hi,

Just wondering what should production be on 8 x 540W panels (1 series string), facing north on a normal pitch tile roof.

The time now is 12:10. It is sunny day day, no clouds. herewith my results:

292.5 Volts

11.2 Amps

3.27 KW

Does the above results look right?

Inverter 8KW SunSynk

I have 2 strings of the JA 535W panels. 6 Panels each. The 540W and 535W are very close in specs. See attached spec sheet.
My two strings are paralleled around 6 meters from the inverter and the cables from the panels to where they are joined is around 8 meters.
For a test I then strung 9 Panels in series as a single string. VOC  should be around 440-450.
I measured it with a Fluke at about 420V at the joint.
Once the additional 6 meters were connected it dropped  to around 400V.
Then I put a nice load on it and that dropped it to around 310V.
The amps are as per the panel specs i.e. at around 13,8A. So the result was around 4200W.
image.png.dab8bc138330ecd02ea42fbb9b9a906b.png

JAM72S30 525-550 MR Global_EN_20200904A.pdf

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Posted
28 minutes ago, Sc00bs said:

100% correct @Antonio de Sa but only when the battery is fully charged/you are hitting the max amount of power you can put into the battery and you are not feeding back into the grid, the inverter has nothing to do with the extra power so the MPPT's will increase resistance to the panels which will reduce the amperage coming from the panels. This however does not affect the panel voltage which will remain constant. 

The formulae for the power the panels are generating is Power = Volts X Amps so if you are loosing volts due to cable loss it will reduce the amount of power you get from the panels. 

@Sc00bs Yes indeed, but the system should still be able to produce the necessary power by increasing the current to supply the necessary wattage. at least mine does that see dashboard.

 

image.thumb.png.9ce7698f48a14deee888de500fe92bda.png 

  • 0
Posted
45 minutes ago, Antonio de Sa said:

It will depend on you house load, try increase the load and you should see your PV production should increase accordingly.

@Antonio de Sa no need to as I am exporting to the grid

 

43 minutes ago, Sc00bs said:

What make panels are they?

@Sc00bs JA Solar as per heading

 

44 minutes ago, Sc00bs said:

How long are the cables to your panels

@Sc00bs +-20 meters

 

44 minutes ago, Sc00bs said:

Are those the maximum numbers that you have on record? 

@Sc00bsFor this time of year yes

 

Thank you for the replies

 

 

 

 

540.png

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