A novel methodology for determining sky blocking by obstacles viewed virtually from any location on site

This paper presents an innovative methodology for determining sky blocking by obstacles, when viewed virtually from any location on a site. These sky blockings are defined in the form of azimuth and altitude angles (or position angles) of exposed corners of obstacles around locations, proposed for solar installations at the site. To determine sky blockings, the surveyor does not need to be present at that height or location. Rather few measurements would be taken from two easily accessible points (preferably on ground) and then the results will be extrapolated so as to determine sky blockings from required height or location. Some other surveying parameters are also recorded which are discussed in details. Trigonometric relations are derived which aid in viewing the obstacle virtually from any other chosen point on site which may not necessarily lie in the same plane as of reference points. Steps for performing physical survey are also explained which only requires measuring few angles and lengths. The method is demonstrated with a case study for validation. Ultimately, this innovative approach extends the flexibility in employing already existing sun-path diagram based site analysis methods by allowing surveyor to evaluate angles without physically reaching the desired locations. Application of proposed methodology lies in performing site analysis for solar installations in urban areas where energy is largely consumed.