POA vs GHI

[cson]

As I understand, the POA value should be greater than the GHI value, but why does it show in our project the result like this? 

[Linda Thoren]

The global irradiance in the plane of the array (GlobInc)depends on the tilt and azimuth of your system. In general, one would choose an orientation of the panels in a way that maximizes this irradiance, which is why the GlobInc is usually higher than the irradiance on a horizontal plane.  

When defining a fix tilted plane, you find a "quick optimization tool", illustrating in an order of magnitude what you could expect to gain (or lose) compared to a horizontal configuration at your site.