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General Solar Position Calculator

Reviewed by Calculator Editorial Team

The General Solar Position Calculator determines the solar azimuth and altitude angles for any given location, date, and time. This information is essential for solar energy applications, astronomy, and engineering projects.

What is Solar Position?

Solar position refers to the apparent location of the sun in the sky, defined by two key angles:

  • Solar Azimuth Angle: The angle between the sun's position and true north, measured clockwise from north.
  • Solar Altitude Angle: The angle between the sun's position and the horizon.

These angles change throughout the day and vary with the season and location on Earth. Understanding solar position is crucial for solar panel installation, daylighting design, and astronomical observations.

How to Use This Calculator

To calculate the solar position:

  1. Enter your location coordinates (latitude and longitude).
  2. Select the date and time for your calculation.
  3. Click "Calculate" to get the solar azimuth and altitude angles.
  4. Review the results and use the chart to visualize the solar path.

Note

This calculator uses the standard solar position algorithm that accounts for Earth's elliptical orbit, axial tilt, and atmospheric refraction.

Formula Used

Solar Position Algorithm

The calculator uses the following steps to determine solar position:

  1. Calculate the Julian day and Julian century.
  2. Compute the geometric mean longitude and anomaly.
  3. Determine the eccentricity of Earth's orbit.
  4. Calculate the equation of time and true solar time.
  5. Find the solar declination and right ascension.
  6. Determine the solar azimuth and altitude angles.

The complete algorithm is based on the Solar Position Algorithm for Solar Radiation Applications developed by the National Renewable Energy Laboratory.

Worked Example

Let's calculate the solar position for New York City (40.7128° N, 74.0060° W) on June 21, 2023 at 12:00 PM (noon).

Parameter Value
Latitude 40.7128° N
Longitude 74.0060° W
Date June 21, 2023
Time 12:00 PM
Solar Azimuth 180.0° (South)
Solar Altitude 68.5°

At this time, the sun is directly overhead (azimuth of 180°) with an altitude of 68.5°, which is typical for the summer solstice in New York City.

FAQ

What are the units for solar azimuth and altitude?

Solar azimuth is measured in degrees clockwise from true north, while solar altitude is measured in degrees above the horizon.

How accurate is this calculator?

The calculator uses standard astronomical algorithms with an accuracy of about ±0.5° for most locations and times.

Can I use this for solar panel installation?

Yes, the solar position information can help determine optimal panel angles and orientations for maximum energy production.