This non-electronic instrument is an easy-to-use tool that accurately measures the shading of any site, allowing the user to see what could shade the system throughout the year. Because the Solar Pathfinder™ works on a reflective principle rather than actually showing shadows, it can be used anytime of the day, anytime of the year, in either cloudy or clear weather. The actual position of the sun at the time of the solar site analysis is irrelevant. In fact, the unit is easier to use in the absence of direct sunlight. It could even be used on a moonlit night.