Screen Shots - SunPlot3D

PV-DesignPro | SolarPro | Worldwide Hourly Climate Generator | IVTracer | ModuLab| SunPlot3D

Purpose: The SunPlot3D program was designed to be an effective tool to determine the Sun's position using an interactive three-dimensional display. It is also a valuable learning and experimentation laboratory enabling a user to become familiar with solar energy geometry in general.

After starting the program, a series of simple steps can be followed that will explain most of the necessary specifics of using the program:

1. Enter the site's latitude (N+, S-, range: +90 to -90) in the Latitude text box. Decimal values are accepted. Also, you can use the vertical slider bar to the left of the world map to adjust the latitude, however, the range will not include any decimal values and may be difficult to adjust exactly.

2. Enter the site's longitude (West of Zero Longitude, range: 0 to +360) in the Longitude text box. Decimal values are accepted. Also, you can use the horizontal slider bar on the bottom of the world map to adjust the longitude, however, the range will not include any decimal values and may be difficult to adjust exactly.

3. Enter the site's standard meridian (West of Zero Longitude, range: 0 to +360, with 7.5 degree increments which correspond to 30 minute changes in standard time zones) in the Standard Meridian text box. Decimal values are accepted. Also, you can use the horizontal slider bar on the bottom of the longitude slider bar to adjust the standard meridian. You can also click on the world map to adjust the latitude, longitude, and standard meridian, however, the coordinates will not be exact and the standard meridian may need further adjustment to correspond to an actual standard meridian.

4. Adjust the desired date and time for the determination of the Sun's position using the UpDown controls for Month, Day, Hour, and Minute. Seconds can be entered directly if desired. Note that the program will update automatically (chart and data output text boxes) when the mouse button is released from an UpDown control. Also, be careful the Day corresponds to an actual day. The day will adjust from 1 to 31 and February only has 28 days. If the day is set to 31 and the month 2, you will be actually seeing the results for March 3rd.

5. The Declination and Equation of Time charts show the hourly values of these data series for the year, and also the current value with a red dot. You can expand these charts to full screen by right-clicking the chart and then selecting "Maximize" from the pop-up menu.

6. Select the tracking method for the solar module. The program will update after a new method is selected with the option buttons.

7. If available, enter the slope and azimuth for the selected tracking method. For certain types of tracking, one or both of these options may not be available. The program will update upon release of one of the UpDown controls, however if you enter these values directly into a text box, you will have to press the "Calc" button for the program to update.

8. You now should be seeing a chart and data output text boxes updated for the values entered. If for some reason you want to update to make sure the program is displaying data for current values, you can press the "Calc" button at any time.

9. The chart can be rotated using the bottom and right slider bars. The chart can be expanded to full screen by right-clicking on it and selecting "maximize". Also, printing and other options are available from this pop-up menu.

10. To the bottom of the chart are values for various data outputs explained in the definitions section. The radiation on the surface of the solar module surface is calculated using the Perez model.

The program was designed for visual, interactive, and rapid experimentation. Feel free to click on the world map to set a location, adjust the date values liberally, and observe the solar and module positions on the chart. Then, rotate the chart as needed to get a good view of what’s happening with the relative positions of the Sun, Earth, and solar module. Then repeat the process. After some time with this type of experimentation, you will have a better understanding of Sun positions, solar module tracking, and influences on incident solar irradiation.