The SAM 3D Shade Calculator uses a sun position algorithm and a three-dimensional drawing of a photovoltaic array and nearby shading objects to generate hour-by-month tables of beam irradiance shade loss percentages, and a sky diffuse loss percentage. It has the following features:
•Uses Bing Maps geocoding to automatically find latitude, longitude, and time zone for any street address.
•A three dimensional drawing, or shade scene, represents the photovoltaic array and nearby shading objects.
•The scene consists of active surfaces (photovoltaic subarrays) and shading objects.
•Four three-dimensional shapes are designed to represent most shading objects: Box, cylinder, tree, and roof.
•View and edit the shade scene in three-dimensional, bird's eye, and elevation views.
•Add an optional aerial photograph from Bing Maps or your own image as an underlay for the bird's eye view to help position objects on the scene.
•Drag the three-dimensional view to see shadows on active surfaces and the shade loss at different sun positions.
•Calculate diurnal and hourly beam irradiance shade loss for a single year based on the scene location and relative positions of each active surface and shading objects in the scene.
To use the SAM shade analysis calculator:
1.On the Shading and Layout page (detailed photovoltaic model) or System Design page (PVWatts), click Open 3D shade calculator.
2.Define the scene location (latitude, longitude, time zone).
3.Add shading objects to the scene -- these are trees, buildings, and other structures near the array that may block direct solar irradiance from reaching the array.
4.Add active surface objects to the scene to represent the photovoltaic array or subarrays.
5.Save and close the calculator to apply shading factor values to the SAM shading inputs.
7.Export shade data to use in SAM or other simulation software.
For more step-by-step instructions, see How-To.
For a description of the 3D shade calculator's features, see Reference.
