Can You Use a Solar Compass to Find True South?

Understanding Magnetic Declination

Magnetic declination, also known as magnetic variation, is the difference between true north and magnetic north. This value varies depending on your location and can range from -20 to 20 degrees. For example, in the city of Denver, Colorado, the magnetic declination is approximately 7 degrees west. Using a solar compass to find true south in this location would require adjusting for the declination.

Solar Compass Techniques

To use a solar compass to find true south, follow these steps: 1) locate the shadow of a vertical stick or object on a flat surface at solar noon; 2) draw a line between the end of the shadow and the top of the stick; 3) draw another line perpendicular to the first line; 4) the intersection of these two lines should be approximately true south. However, this method assumes a relatively small declination value and is not suitable for locations with large magnetic declination.

Practical Considerations

In practice, solar compasses are often used as a rough guide for estimating true south, rather than a precise measurement. For accurate installations of solar panels, it is recommended to use a combination of methods, such as GPS readings, magnetic declination calculations, and on-site measurements, to determine the optimal azimuth angle for maximum energy production.