Annual yield calculation

[Maggie]

Hi,

Can you please tell me what power rating is used when calculating the annual yield of an inverter - is it the nominal (rated power) or the VA rated (apparent) power? 

Many thanks.

[hotline_oh]

Dear Maggie,

Thank you for your inquiry.

If you specify a displacement power factor (cos φ < 1) in the options, the inverter's active power will be used instead of its apparent power.

[Maggie]

Thanks.  If I change the pf to < 1, I can see that the active power reduces appropriately -  e.g. 40kW inverter pf 0.9 --> active power = 39.6 kW.  If I leave the pf at unity, the active power is 40kW, not 44kW.  Which value does PVSol use to determine the yield - 40kW or 44kW - thanks.

[Maggie]

Hey, I'd really appreciate some help on this - thanks.

[hotline_oh]

Dear Maggie,

Thank you for your inquiry.

Both values are provided by the manufacturer Ginlong (Solis) in our database. 40 kW is the AC Power Rating in kW (active power). This value indicates the power at which the inverter generates the optimal yield. 44 kW is the max. AC Power in kVA (apparent power). This value is a limit.

In the diagram editor, you can see that the output is curtailed to 40 kW on sunny days. However, since you are planning an east-west facing system, a power output of 40 kW will probably not be achieved even on sunny days.

[Maggie]

@hotline_oh So when calculating the predicted yield, PV Sol only considers the power rating of the inverter (in this case 40kW) as the maximum o/p.  Appreciate your help - thank you.