1. Consider the size of the area needing illumination: The size of the area needing illumination will determine the brightness and wattage of the solar street light you need.

2. Consider the weather conditions: Solar street lights are most effective when they are installed in areas that receive direct sunlight for most of the day, as they need to be able to absorb enough energy from the sun to be able to power the lights at night.

3. Choose between LED or CFL lighting: LED street lights are more energy efficient than CFL lights, but they also cost more. You may want to consider your budget when deciding between the two.

4. Choose between mono-crystalline or poly-crystalline panels: Mono-crystalline panels are more efficient than poly-crystalline, but they also cost more.

5. Consider the type of control you want: Many solar street lights come with motion sensors, timers, or can be controlled remotely. Consider all of your options before making a purchase.