# Question about the "Sizing factor"

## Recommended Posts

Hello to all.

I am new and learning about all the process on PV SOL.

I am planing a photovoltaic system and the "Sizing Factor" is showing me a factor of 154,9 but I don't understand how PV SOL calculates this value. The Interverter can receive up to 7,5 kWp in the south direction of the roof and 8,5 kWp in the west and east direction of the roof. The actually photovoltaic system reach 7,13 kWp on the interverter and the direction of roof is east.

My Question is:

Why is showing me the "Sizing Factor" a factor of 154,9 although the inverter has not yet reached its actual limit?

Greets

Here is a Picture:

##### Share on other sites

Hi apaec,

the sizing factor is defined as the installed DC power of the PV modules in relation to the AC power of the inverter. So, if you have 100 kWp of PV modules, and an inverter of 100 kW AC output, you'll get a sizing factor of 100%. If you have 150 kWp PV module power connected to a 100 kW inverter, that would be a sizing factor of 150%.

The sizing factor is a design choice. The higher the sizing factor, the smaller the inverter. Smaller inverters usually are cheaper than bigger ones, so you can save cost there. But then you'll have more down-regulation situations where the PV produces more than the inverter can handle. So the inverter will limit the output and "throw away" the excess energy, so you'll lose some portion of your PV energy. That effect will decrease the profitabitility of your project. So the planner of the PV system has to make a choice which inverter to connect to the PV array. With PV*SOL, you can easily see the impact on the energy yield a smaller inverter (higher sizing factor) would have.

The limits of the sizing factor can be modified in the Options -> Configuration Limits:

Hope that helps, kind regards,

Martin

## Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

×   Pasted as rich text.   Paste as plain text instead

Only 75 emoji are allowed.

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

×
×