Theoretical model of solar incident angle for an optionally oriented fixed flat surface

The apparent position of the Sun in relation to any surface is defined by solar incident angle. angle forms vector and normal observed surface. spatial aforementioned vectors determined coordinates, which include: declination, latitude, hour angle, longitude, elevation azimuth surface, inclination north-south direction east-west direction. This article describes detail theoretical model for determining an arbitrarily placed fixed, flat using algebra analytical geometry, as well coordinates. study model, was developed combining, modifying, supplementing existing models, can be used determine thermal performance devices such as: collectors, PV panels, hybrid systems.