# Converting the angle to sunpos

Dear all,

I am trying to achieve sing axis solar tracker. I have attached snapshot of the data being recorded and also the data recorded from nrel . My Tracker has been placed in north south direction.From Table it clearly that azimuth from East will be 90 degree increasing if it move in clock wise direction. But my sensor can measure angle from + or - 90 degree format.Question here is how to convert angle to + or -90 degree format to get exact sun position for day of time

http://pveducation.org/pvcdrom/properties-of-sunlight/suns-position

NREL data.zip (745 KB)

It will be due south at local noon. Has been for millions of years. Alternatively, when it is due south it will be local noon.

Why do you need to calculate the angle?

If it is just to orient a solar panel 4 cheap LDRs and a short bit of code to move the panel until the light falls evenly on opposite LDRs is all you need.

...R

Ya i know . lots of way create cheaper solution. But i am looking for solution which gives exact sun position Of tracker.
The zenith and azimuth angle i am getting from Nrel Gives exact position of sun. But i dont know How to Convert these angle to +90 deg to -90 degree format in order to match my Sensor value.

And also from chart it clear that morning my azimuth angle Will be 90 degree from East and keep on incrementing and reach 180 Degree around 12:15 to 12:30. and 270 around 6:30 Pm . How to convert These angle to My sensor angles

Azimuth.pdf (64.7 KB)

Sorry. I'm content with the simple stuff. ...R

Anugraha: But my sensor can measure angle from + or - 90 degree format. Question here is how to convert angle to + or -90 degree format to get exact sun position for day of time

Looks to me like it's already converted. You want to convert +/- 90 degrees to +/- 90 degrees, right?

Perhaps you want to convert +/- 90 dgrees to 0-180? Simple math. Perhaps you want to convert +/- 90 degrees to 90-270? More simple math. Perhaps you want to convert 90-270 to +/- 90? Again, simple math.

Let us know what you REALLY want to do.