2 Axis Solar Tracker (The evolution of an idea)

[rockwallaby]

Nice to see development in this area.

Now I am doing much the same, except that my project incorporates the complete monitoring and control for both solar panel array as well as a micro-hydro system.
I intend also to install a tracking system on the solar array, and am digging big hole in ground as we speak for a 8 metre or for you usa folks a 4x6' triangle mast tower.

Now what i noticed with your design that did strike me with some concern is potential problems with wind loading.
With using pulleys and such, I tend to think that one good gust of wind and your belts would be snapped or slipped and your nice panel will then likely be a lovely weather cock.
I am wondering, is this something you have thought about, or is the total surface area of your panels so small that it would not e effected by such a strong gust?

I will be using a good solid ram drive, similar to what is used for satellite dish positioning, welded steel frame and suitable bearings.

Also, someone mention using a RTC as a backup, that is a good idea.
The system I am designing will not use light sensors for directional operation, but using NTP, network time protocol as my system is connected to the internet anyhow.

You have obviously spent a great deal of time making fantastic CAD drawings which makes it far easier to see and visualise your design.
Looking forward to hearing of your results.

rockwallaby

[graynomad]

Wind loading can be a huge force, I would have a real good look at that.

Speaking of having a good look, anyone doing this sort of thing should check out this thread on the Aussie electronics forum

http://www.ozelecforum.com/viewtopic.php?f=33&t=108

As for the second axis, I think most people reckon it's not worth automating, just go out every 2-3 months and adjust them.

______
Rob

[Khalid]

i have worked on my own dual axis sun tracking system. It is menu driven and all the parameters can be set using 6-key keypad and LCD. Saving the parameters in EEPROM is added.

[graynomad]

Nice Khalid, interesting blogs as well.

______
Rob

[Khalid]

Rob,
Thank you. This blog happen just with the help of nice helpful guys like youl
Regards

[AJITnayak]

Hi,

I suggest to use following methods

1) SPA algorithm code that gives you the exact position of sun.
2) use Inclinometre to measure the inclination for reference input
3)use suitable linear actuator and motor drive , that can drive the load
4) use gps sensor for  getting date and time
5) real time  clock has been used to provide back up incase GPS fails

[Khalid]

Hi AMPS,
The bad thing about the stepper and servo is:
1- The whole system got too much costly
2- You have always keep energize the system ( In case of stepper if you remove the power it will loose holding torque and accuracy may suffer)

When you have a low cost approach then why to complicate the things?

[AJITnayak]

@KHALID.

ITS MY OPINION  , Main  agenda is to provide track the sun . To measure the sun angle accurately for many years with 0.0003 deg.
2) for that time and date has to be accurate , so i suggested GPS and real time clock for keeping time  accurate.
3) in ordered to measure the usually u can use potentiometer ckt  after few year it will loss its accuracy, So i refereed Inclinometre   
4) The person who are going to design the tracking system , He has to take care of the drive and driver unit. I suggested linear actuator and linear actuator drive for that assuming the tracking system for home or residental.

Even we are in to solar tracking system we are successfully running with arduino from past 3 years.

[Khalid]

@AMPS
Actually if you use LEDs or LDRs then you have no worries of degradation. Both have long life.. In Solar Panel you no need that much accuracy. Question is why?
If you move the panels at 0.003 degree interval, then you have to move each second the panel. This will at the end of the day consumes lot of Motor, its drivers and controllers energy.
I am also running the solar panels for past year and i find the good accuracy in positioning of panels.

[AJITnayak]

@khalid



1)It all depend on  programming technique, you can save power whenever motor is not being used
2) LDR  are sensitive dust. When Some dust fall on it . it might not work. It need periodic maintenance
3) 0.003 deg mentioned is not per degree  to moved in everyday. I mentioned because if we use simple code using LDR after year if you reading 30deg for particular time  , U might degrade to  + or - 5 degree after year on same time, If we calculate for long period track will be out of position.

[toxman]

i made this project using bearings and mechanics of an old hard disk.....
nice idea!