I noticed there was a lot of interest in this forum regarding solar tracking. Most of the threads discussing this subject have proposed some sort of photocell control of motors to position a solar array perpendicular to the sun's rays.
Here is a method of predicting where the sun is located for any co-ordinate, date, and time. Photocells are not required. The program outputs the Azimuth Angle (degrees from North) and Elevation Angle (degrees from horizontal) which can be used to move the array to the right spot.
For now, this is strictly a mathematical exercise. I am hoping to build a complete tracker for a small solar array to work out the drive electronics and find a suitable 2-axis positioning mechanism and motors.
I was looking for any articles on the Internet regarding this subject matter and came across this article from Rockwell Automation:
https://www.electro-tech-online.com/custompdfs/2011/11/oem-wp009_-en-p.pdf
I noticed that their software included an algorithm provided by NREL (National Renewable Energy Laboratory) located near Golden, Colorado. This led me to the NREL web site where I was able to download the NREL/TP-560-34302 Revised January 2008 manual.
**broken link removed**
By registering, I was able to download the spa.c, spa.h, and spa_tester.c source code modules.
I used the same microcontroller board I described in my Grid Tie Inverter Prototype post and loaded the attached project code. It worked very well. I am sure that you PIC users can find a processor with floating point support and port the code to your favorite compiler.
I noticed in the example code that NREL used co-ordinates 39.742476,-105.1786 and if you plug this into Google Earth search box, it will take you to the NREL facility. They have a large solar farm and if you look carefully, there is a moveable array enclosed by a fence casting a large shadow on the ground.
Here is a method of predicting where the sun is located for any co-ordinate, date, and time. Photocells are not required. The program outputs the Azimuth Angle (degrees from North) and Elevation Angle (degrees from horizontal) which can be used to move the array to the right spot.
For now, this is strictly a mathematical exercise. I am hoping to build a complete tracker for a small solar array to work out the drive electronics and find a suitable 2-axis positioning mechanism and motors.
I was looking for any articles on the Internet regarding this subject matter and came across this article from Rockwell Automation:
https://www.electro-tech-online.com/custompdfs/2011/11/oem-wp009_-en-p.pdf
I noticed that their software included an algorithm provided by NREL (National Renewable Energy Laboratory) located near Golden, Colorado. This led me to the NREL web site where I was able to download the NREL/TP-560-34302 Revised January 2008 manual.
**broken link removed**
By registering, I was able to download the spa.c, spa.h, and spa_tester.c source code modules.
I used the same microcontroller board I described in my Grid Tie Inverter Prototype post and loaded the attached project code. It worked very well. I am sure that you PIC users can find a processor with floating point support and port the code to your favorite compiler.
I noticed in the example code that NREL used co-ordinates 39.742476,-105.1786 and if you plug this into Google Earth search box, it will take you to the NREL facility. They have a large solar farm and if you look carefully, there is a moveable array enclosed by a fence casting a large shadow on the ground.