Calculating Solar Angle of Incidence
The angle of incidence describes the angle of the sun above the horizon for a given location on a given date; this is also called the sun elevation, or solar inclination. Since the angle of the Sun above the horizon also determines how much insolation a location receives, this information is commonly used in industries like green construction, where the angle of incidence at different times of the year is factored into architectural designs of buildings that try to passively maximize solar efficiency.
You are hired by an architectural firm to be their solar insolation expert. A client would like to build a home near Sandpoint in northern Idaho with a sun room that captures maximum light in the winter months, but uses an awning to block the hot summer sun and keep the room in the shade. In order to determine the size and angle of the awning, your boss asks you to calculate the maximum and minimum angles of incidence for the location of the home.
Latitude of home: 48 degrees North
1. Calculate the minimum angle of incidence.
The minimum angle of incidence in the Northern Hemisphere occurs on December 21st. What latitude is the Sun directly overhead on December 21st? ________
Since the Sun is directly overhead at 23.5 degrees South latitude, you need to calculate the angle of the Sun n Sandpoint for that date using basic geometry. Watch the video below and follow along to see how this is done.
You are hired by an architectural firm to be their solar insolation expert. A client would like to build a home near Sandpoint in northern Idaho with a sun room that captures maximum light in the winter months, but uses an awning to block the hot summer sun and keep the room in the shade. In order to determine the size and angle of the awning, your boss asks you to calculate the maximum and minimum angles of incidence for the location of the home.
Latitude of home: 48 degrees North
1. Calculate the minimum angle of incidence.
The minimum angle of incidence in the Northern Hemisphere occurs on December 21st. What latitude is the Sun directly overhead on December 21st? ________
Since the Sun is directly overhead at 23.5 degrees South latitude, you need to calculate the angle of the Sun n Sandpoint for that date using basic geometry. Watch the video below and follow along to see how this is done.
Your Turn
Now, calculate the maximum sun elevation for the house near Sandpoint on June 21st, the day of the solar maximum. Try and do this on your own, then watch the video below to see the answer.