Which is the right direction for my solar panels?

To get the maximum sunlight, the right direction for your solar panels is either True North or True South.

It is true North for people living in the southern hemisphere such as Australia.

And

True south for those living in the Northern hemisphere like India.

The true south and true north are also called geographical South and geographical North respectively.

And

These are collectively called geographical poles.

Read: How to find the right solar tilt for maximum sunlight?

Magnetic Poles and Geographical (True) Poles are different

The magnetic compass does not point to the geographical poles of the earth.

It points to the magnetic poles of the earth.

And

The magnetic poles and the geographical poles are two different things.

Also,

The magnetic pole that is near the geographical south pole is actually the Magnetic North Pole.

A bit confusing!

Let me clear things up with a pictorial example.

Our earth behaves like a magnet.

You can see that the magnetic pole near the geographical south is the Magnetic North of the Earth.

In terms of magnets, the opposite poles attract.

It means the north of the magnetic compass is the magnetic south of the earth.

Similarly, the south of the magnetic needle is the magnetic North of the Earth.

In simple words, the north of the magnetic compass is attracted by the magnetic south of the earth which is close to the earth’s geographical North.

The magnetic field lines always run from the North of a magnetic pole to the South of the earth’s magnetic pole.

While on another hand,

The geographical North and the South poles of the earth are the points from which the earth’s axis of rotation passes.

The axis of the rotation of the earth and the line joining its magnetic poles do not align.

(The green line and the red line do not align)

Note: Although it is the opposite. Still, we take the magnetic compass needle direction as the Earth’s magnetic pole direction.

Why these two lines are different?

Because these two originate from different mechanisms.

The magnetic field lines are originated from inside the earth.

It is due to the circulating current produced by the molten iron inside the earth.

The earth’s magnetic fields are continuously changing with respect to its geographical poles.

These are due to the changes in the magnetic flux in the Earth’s outer core.

While on the other hand, the geographical poles are the points around which our earth is rotating.

The magnetic poles of the earth due to the changing magnetic field may or may not align with the True North or the True south pole.

This is the reason behind the difference between the magnetic and true poles.

How to find the direction (True North or True South) of your solar panels?

The magnetic compass alone cannot find it.

We need to use a combination of the methods to get the true North or the true South.

Let us discuss one of those methods.

a) Using magnetic declination and the latitude of your location

The magnetic declination is the angle between the geographical North and the magnetic North of the earth.

This is represented in the above picture as θ.

The magnetic compass gives me the direction of the magnetic poles.

And

If somehow, I get to know the magnetic declination.

I can then rotate the compass by the amount of the magnetic declination and get the true south or the true north pole.

Take a magnetic compass and align it along the North and South point.

You will get the magnetic poles of the Earth.

Now find the magnetic declination of your location.

There are websites that can help you out with this.

I refer to the NOAA website to get the magnetic declination values.

If the magnetic declination of your location is west, rotate the compass clockwise by the same number of degrees in declination.

If the declination is east, rotate counterclockwise.

An Example

Let us understand it with the help of an example.

Suppose your location is New York.

The magnetic declination of New York is 12° 38’ West.

Now to get the true North in this case.

First, align the magnetic compass needles along the North and South points.

Thereafter, rotate the compass clockwise by 12° 38’ to get the true North.

(Note: The magnetic North pole is found to be located at 83°06′N 117°48′W in 2005).

For New Delhi, the magnetic declination is 1°16’ East.

Now as it is East, I must rotate my compass counter-clockwise by this to get the true North or South line.

Let us see the magnetic declination of some of the major cities of the world as on October 21, 2022.

• Tokyo (Japan): 7° 49’ West
• Sao Paulo (Brazil): 21° 43’ West
• Shanghai (China): 6° 26’ West
• Berlin (Germany): 4° 42’ East
• Mumbai (India): 0° 7’ West
• Istanbul (Turkey): 5° 58’ East
• Buenos Aires (Argentina): 9° 45’ West
• Lagos (Nigeria): 1° 32’ West
• Cairo (Egypt): 4° 45’ East
• Mexico City (Mexico): 4° 7’ East
• Manilla (Philippines): 2° 36’ West
• Canberra (Australia): 12° 34’ East

b) Using the shortest shadow method

This method is based on the principle that when the sun is at its highest point at Noon.

The shadow formed is the shortest.

And

The line joining the ends of the shadow is the true North/South line.

• Choose a day when the sky is clear and the sun is shining.

(Wait till 11:10 AM for the sun to rise).

• Take a stick
• Mount it straight on a flat surface or ground.
• The sun will cast its shadow
• As the sun rises, the shadow position will change and its length will start decreasing.
• To get the shortest shadow length, after every few minutes, start marking points at the end of the shadow.

• When you observe that now the shadow starts appearing longer than the previous one.
• Stop the activity, the previous one is the shortest shadow.
• Join those endpoints, you get the True North/South line.

You can use any of the above two methods for finding the right direction for your solar panels.

I prefer the shortest shadow method. Because even if I don’t have any gadgets, I can find the true North/South line by using a simple stick.

If you are a solar enthusiast who is interested in Do-it-Yourself Solar.

Then the best DIY solar blogs will help you in gaining the right solar skills.

Friends, look for the best DIY solar blogs and website to get more DIY solar

Conclusion

We should face our solar panels either towards True South or True North.

For people living in the Northern Hemisphere like India. Keep your solar panels in the true south direction.

And For people of the Southern hemisphere, they should face their solar panels in the true North direction.

This improves the financial feasibility of the solar power system and makes it more attractive.