Tree Canopy Transparency values for energy simulation

I’m relatively new to Grasshopper and I am trying to use trees as the context in my energy simulation.
I would like to know if there is any database for "tree canopy transparency " values for various kinds of trees or is it just an assumption?
Would be great if anyone could share videos on modelling trees for energy simulaiton

Hi @Visakha,

Check out this thread, I think it has what you are looking for