Yield reduction due to shading with Export Control

[BorisG]

Hi PVSol Team,

I'm having troubles understanding the Yield reduction due to shading. I've read that it's the percentage difference between shaded and unshaded simulations. 

When export control is activated the reduction is lower (for identical systems). Where does the difference come from/how exactly is it calculated when export control is turned on?

I would have guessed the shading losses to increase with export control because the clipping is usually during the midday when shading is low, so we remove production with "low shading". I think the presentation of the data in this way may be misleading.

Attached are two screenshots for the identical system with only export control (0%) activated.

Thanks in advance!

Boris

 

[developer_mh]

Hi Boris,

the 'Yield reduction due to shading' is calculated as the ratio of the PV Generator Energy (AC) minus the Clipping at the Feed-in Point without shadows and the same number with shadows. So, as example you have the following (the numbers are from one of our example projects).

System 1, without feed-in clipping/export control:

without shadows:

• PV Generator Energy (AC) =145,377 kWh
• Feed-in Clipping = 0 kWh

with shadows:

• PV Generator Energy (AC) =132,972 kWh
• Feed-in Clipping = 0 kWh

Yield reduction =1 - (132,972 - 0) / (145,377 - 0) = 8.6 %

 

 

System 2, with feed-in clipping/export control:

without shadows:

• PV Generator Energy (AC) =145,377 kWh
• Feed-in Clipping = 59470 kWh

with shadows:

• PV Generator Energy (AC) =132,972 kWh
• Feed-in Clipping = 52,822 kWh

Yield reduction =1 - (132,972 - 52,822) / (145,377 - 59470) = 6.8 %

 

Hope that helps, kind regards,

Martin

Edited September 26 by developer_mh
Added the note that the numbers come from one of our example projects