Solar Light Project HowTo: 09.22.2008
Description: Basically, a small amorphous silicon 1.5W solar panel was purchased from Harbor Freight Tools for $13.99 and hooked directly to a small light.  When the sun is shining, the power from the panel illuminates the light.  When the sun is away, it doesn't light at all.  I also call this the "Hey, the sun is out" sensor.   
 

System Diagram:

 

 
 

Image of the light and the solar panel which is powering it.  Wire is fed through the skylight.