EME 810
Solar Resource Assessment and Economics

2.16 Applying Shading Factors in SAM


System Advisor Model

I hope you were successul installing SAM software and getting it ready to use in the last lesson. Now you will be applying your interpretation of the shading diagram to determine shading factors and input them into SAM for system energy performance simulations where shading interferes with the solar resource.

We have come a long way in interpreting sun path diagrams and plotting shaded areas as overlays onto the sun path charts. How can we input those shade/no-shade conditions to the PV performance model in SAM? The video below provides a demo of how shading conditions can be applied in SAM simulations. 


This video is made using the 2020 version of SAM. In newer versions some tab specifications may be differ.

Video: SAM Shading Intro (6:26)

SAM Shading Intro
Credit: M. Fedkin © Penn State University is licensed under CC BY-NC-SA 4.0

So, the important take-aways are that we can use SunCharts or other geometric shading data to get us to a shade-based performance adjustment of PV performance simulations, and that shading matters in solar energy. How significant can it be? Quite significant, but you will get a more accurate answer after performing your homework assignment in this lesson! We use these SAM simulations in solar project design, and this will be the way to assess the shading losses for any specific scenario (and in your final course project eventually). 

When working with SAM shading table, we can input partial values for hours that are on the shade/no-shade boderline (e.g. 50% etc.). SAM conveniently grades the color scheme from white (full sun) to red (full shade) in the process. Also, note that the locale matters! Do not forget to set your location in the Location and Resource tab first: the default for SAM is often in the Southwest USA, and you will need a correct solar resource file before running your simulations.