ALAN/ALAN D wrote: ↑Sat Sep 09, 2023 9:33 am
Hello Gents
I am going to build a system that follows the big Yellow Thing and moves position and angle on a daily basis.
Is there any software / calculator to tell you in real time the angle and position required.
Having only got 38 fixed panels I decided to have a go at a motorised system
In simple terms yes. The position on earth directly underneath the sun at any point in time can be computed and is published in a sun almanac as a the sun's declination and Greenwich Hour Angle. The declination varies seasonally from +23.5 to -23.5 degrees and is the latitude of the point directly underneath the sun. The GHA varies throughout the day as the earth rotates and seasonally by the equation of time which is the offset difference between true noon at Greenwich (when the sun is at its highest) and noon GMT. This is why it is Greenwich Mean Time and not just Greenwich Time and the difference varies throughout the year by about +/- 15 minutes.
Thus, from an almanac and an accurate clock, you can find the lat and long of the point under the sun at any point in time. From these you can calculate the sun's altitude (height above the horizon) and azimuth (direction - approx east at 6am, south at midday and west at 6pm).
I am sure that an online version of the almanac is available. The calculation can be done by spherical trigonometry. 40 years ago when I did navigated yachts using sun sights, I easily did the calculation on a cheap Casio calculator. Alternatively you could use a special set of log tables (sight reduction tables) to do the calculation. I could regularly get running fixes with an accuracy of 1 mile. Now in the days of GPS, sunsights are a lost art.
But as others say, don't bother and just get more panels to fill the space you would have to keep clear to allow a tracker to turn.