The SunTrack system can reflect the sun in my house and keep the reflection all day. That way it is possible to have a lot of light in my living room witch is facing east.
With a KlikAan remote control (433mhz) it is possible to:
Calibrate the sun postion by relecting the sun back and ajust the shadow.
Move to a point where the reflection should be, and save 3 reflection points.
Select one of the three reflection points and stay there by adjusting the rotors.
Power down: go to the sleep position.
(via hack a day)
Here’s an (older, largely text-based) description of a solar concentrator; please comment with links to others!