Problem with incident radiation results from LB

grasshopper ladybug
1

I’m trying to estimate the PV production on a complex BiPV facade, but seems to get very different incident energy measurements from LB compared to PV-GIS…
What am i doing wrong (as a new user I can’t upload the file but have attached screenshots)?

LB gives me incident light of 705kwh/sqm in Berlin while PV-GIS gives me 922kWh/sqm

I’ve just installed the most recent LB 1.1 version on Rhino 7-mac.

Screenshot 2020-12-21 at 13.11.23
Screenshot 2020-12-21 at 13.11.233702×1742 682 KB

Thanks
anders

2

To improve accuracy (as suggested in the help popup) I’ve tried replacing LB SkyMatrix with HB skymatrix, but can’t get it to run. LB incidentRadiation throws up an error…about object not having ‘data’ attribute.

Screenshot 2020-12-22 at 15.59.24
Screenshot 2020-12-22 at 15.59.243112×1402 590 KB

What am I doing wrong?

thanks
anders

3

Don’t plug a Legacy object into an LBT component unless it’s some standard data type like a float or text.

As the LBT Ladybug component says, it computes INICIDENT radiation (without any reflections). It sounds like PV-GIS is making an assumption about ground reflectance to give you incident + reflected radiation.