Soiling and IAM values problem for POA input

Good afternoon.

I was simulating a scenario on SAM just it is described on my other question ( sam.nrel.gov/forum/forum-general/3856-time-step-of-weather-data.html?start=6 ). I repeated all ten days of data all over the year (this data contains GHI and POA as irradiation input) to have a complete year of data, but I found some problems.

First, when I check the checkbox "POA from pyranometer" in "Location and Resource"-->"Irradiance Data(Advanced) ", the simulation results on a scenario which consumes energy, not generating energy. But if I check the checkbox "POA from reference cell" the simulations results on a scenario which generates energy (with the Soiling and IAM problems I describe below).

Second, when I simulate I get  values of Soiling and IAM that are unreal (image below). Theses values doesn't change even when I consider zero values for both.



For last, if I give the software any values of shading my results are also a scenario which consumes energy. I know my POA data already contains shading and soiling losses (it is from the pyranometer on field), but still it shouldn't results on scenarios that consumes energy. It's so extreme.

I wish you, SAM team, to clarify theses points, please.

Best regards, Gabriel.

Hi Gabriel,

Thank you for this information.

We will address this in response to this thread on the same topic:

sam.nrel.gov/forum/forum-general/2123

Best regards,
Paul.