Jay, the use of concentrators especially parabolic reflectors requires very accurate tracking of the sun, maybe to fractions of a degree depending on design. The apparent position of the sun in the sky depends on factors such as the air density and pressure especially at low sun angles. A straightforward rotator aligned with Earth's axis won't work well without a tracker to compensate for atmospheric distortion. How accurately do you need to keep your reflector aligned to the sun?

 hey Tony thnx a lot.

There is another way to track the sun by this collector.  You can calculate the position of the sun as a function of the time.  You can either use this online calulation websites:

http://www.pveducation.org/pvcdrom/properties-of-sunlight/sun-position-calculator

http://www.sunearthtools.com/dp/tools/pos_sun.php

or calculating the altitiude and the azimuth of the sun through their formulae.  You can get their formulae from:

https://en.wikipedia.org/wiki/Solar_azimuth_angle

Then you can design a stepper motor taking in you account the tranformation of the its pulses into steps or angles.

Good luck.

You can track the sun, for this type of collector, by intalling two axis. The position of the first axis is changed each day. for the second you must moved it during the day in order to track the sun.

Another thought, Jay. What sort of solar cell are you using? Single or multijunction? If multi, how many junctions? I am asking this because such cells are (extremely) sensitive to the spectrum of the incident solar energy. This will change a LOT as the sun approaches the horizon. You will find that you get more out of your system if you deliberately aim the reflector slightly off the sun, to rebalance the red and blue components of the spectrum. This misalignment is going to be extremely difficult to calculate.

thnx to all i get the point

thnx to all i get the point