I purchased a cheap 12' long USB cable for the wiring of this project.  

We are going to use this cable to make two wires, each containing four wires inside from the USB cable (Red, Black, Green, and White).  The first wire will run from the solar panel to the project box.  

Measure out the length of cable you need to get from the solar panel into the project box and cut, leaving yourself a little extra in case you mess up.  Solder the Black and Red wires from one end of the USB cable to the Black and Red wires on the solar panel.  Use heat shrink tubing to cover up the solder points.  

The remaining Green and White wires should be soldered to the photocell, which will attach to the acrylic sheet.  Strip the wires on the other end of the USB cable and solder the tips.  We will connect this inside the project box later.