Inverter undersized because outside temperature

[Barbadori]

Hi there,

When I run a simulation in the UK/Ireland area, PVsyst always uses the Nom. AC Power. The average temperature in this area is around 15 degrees Celsius so I don't understand why uses Nom. AC Power instead Max. AC Power. Am I undersizing the projects I'm designing because of this?

 

 

Many thanks in advance.

[dtarin]

The PV engineer should determine the number of inverters to use in PVsyst and enter that number, taking into account elevation, ambient temperature, etc. PVsyst will display Pnom on the report, however if you check the 8760, it will reach 215 max output (assuming you have the irradiance and enough DC), not 200. Inverters are not sized by the average temperature of a location, though. Usually a higher temperature is selected so that nameplate is guaranteed for most operating conditions (http://ashrae-meteo.info/v2.0/).

Note that the inverter manufacturer has defined Pnom here, not PVsyst. Nevertheless, your output is not being limited to Pnom.

[Barbadori]

Thanks very much for the reply.

I'm not sure what you mean with checking the 8760. Do you mean the output file from the advance simulation? There are so many different options to select there.,, do you know if there is one that shows the maximum output per inverter?

[dtarin]

Yes, the hourly output file. The variable to select is inverter output (EOutInv). It will be the sum of all inverters. Check the maximum hourly output against the (number of inverters * inverter rating).