Dear all,

Hope this message finds you all well

I would like to ask , what factors affects the specific yield for the same location .

as what I did try is to choose different panels and compare the specific yield . and some results were just making no sense

some panels were have better efficiency , better temp. coefficients and still have lower specific yield 

So it will be helpful if one of you guys try to explain what really affects the specific yield calculation

 

Best regards,

Ahmad Elghobashy

Dear Ahmad,

 

Yes, the characteristics you have mentioned play a role but it also depends on the part load characteristics of the module. This represents the efficiency of the module under low irradiation conditions. If you take a look at the efficiency curves of the modules you can see the differences. In the screenshot below the module on the right hand side has a better performance under low irradiation conditions.

 

 

The curves can be found in the database.

 

Best regards

 

Your Support

Ok this so much helpful
but now I have another question , is this curves can be edited in the user created panels , and if possible how can this be achieved ?

Dear Ahmad,

 

The curves are calculated by using the I/V part load characteristics. They are entered in the database. The manufacturers have the possibility to enter specific characteristics for the defined module. If they don't do this then a typical part load behaviour depending on the module type is assumed.

 

 

Please also take a look in the programs help to find out more. In the section "Basis of Calculation" > "Power Output of PV modules" you will find a detailed description on that.

 

Best regards

 

Your support

Thanks for your reply