The elevation angle (also known as the altitude angle) is the vertical height of the sun measured from the horizontal. Both altitude and elevation are used interchangeably to define the height in meters above sea level. When the sun is straight overhead, the elevation is 0° at sunrise and 90° at sunset. (This occurs for example at the equator on the spring and fall equinoxes). Throughout the day, the elevation inclination changes. It is also affected by a location’s position and the day of the year.
What is the Use of Elevation Angle?
The maximum elevation angle, or the maximum height of the sun in the sky at a given time of year, is an essential parameter in the construction of photovoltaic systems. This maximum angle of elevation happens at solar noon and is affected by latitude and declination.
On the summer solstice, the sun is straight overhead and the angle of elevation is 90° at the Tropic of Cancer. This angle at solar noon is higher than 90° in summer at latitudes between the equator and the Tropic of Cancer, indicating that sunlight is coming from the north rather than the south, as it is in most of the northern hemisphere. Similarly, at locations between the equator and the Tropic of Capricorn, sunlight is incident from the south rather than the north at certain times of the year.
While the maximum elevation angle is used in even the most basic PV system design, a more accurate PV system simulation requires an understanding of how the angle of elevation changes throughout the day.
Also Read: What is Declination Angle?
