Page content

Solar Panel Angle: how to calculate solar panel tilt angle?

Discover how to calculate the optimal solar panel angle for your solar system according to your location and the season. Two calculation methods explained.

How to calculate the Solar Panel Angle of your solar system?

The solar panel angle of your solar system is different depending on which part of the world you are.

Solar panels give the highest energy output when they are directly facing the sun.

The sun moves across the sky and will be low or high depending on the time of the day and the season. For that reason the ideal angle is never fixed.

To get the most sun reaching the panel throughout the day, you need to determine what direction the panels should face and calculate an optimal tilt angle. This will depend on:

  • Where you live
  • What time of the year you need the most solar energy
solar panel angle

Solar panel angle

Calculating the Optimal solar panel Angle

As a rule of thumb, solar panels should be more vertical during winter to gain most of the low winter sun, and more tilted during summer to maximize the output.

Here two simple methods for calculating approximate solar panel angle according to your latitude.

Calculation method one

The optimum tilt angle is calculated by adding 15 degrees to your latitude during winter, and subtracting 15 degrees from your latitude during summer.

For instance, if your latitude is 34°, the optimum tilt angle for your solar panels during winter will be 34 + 15 = 49°.

The summer optimum tilt angle on the other hand will be 34 – 15 = 19°.

Calculation method two

This is an improvement of the general method that gives better results. In this method, the optimum tilt angle for solar panels during winter is calculated by multiplying the latitude by 0.9 and then adding 29°. In the above case example of a latitude of 34°, the tilt angle will be (34 * 0.9) + 29 = 59.6°.

This angle is 10° steeper than in the general method but very effective at tapping the midday sun which is the hottest in the short winter days.

For summer, the tilt angle is calculated by multiplying the latitude by 0.9 and subtracting 23.5°. In the above case example, this angle would be (34 * 0.9) – 23.5 = 7.1°.

For optimum tilt angles during spring and fall, 2.5° is subtracted from the latitude.

    Comment Section

    20 thoughts on “Solar Panel Angle: how to calculate solar panel tilt angle?

    By Harilal Bhatti on 24 May 2016

    Very Easy to Understand

    By Raman Patel on 26 December 2017

    Let me know ,the solar panel angle for Bharuch (Gujarat) India

    By Amarnath.P on 12 March 2018

    let me know the solar panel angle for kerala ( Kozhikode )

    By Maxim on 14 December 2016

    What exactly period is identifited as winter and summer? From which to which month

    By alex r. reonal on 5 October 2017

    we have only twet seasono seasons in the philippines, the dry and wet season. dry season is summer which is approximately from april to june where wet season is te rest of the month of the year

    By ramkripal on 30 December 2016

    i m confused sir
    my location latitude is 21.24

    so my tilt angle is in winter

    1st method
    21.24+15= 36.24

    n 2nd method
    (21.24×0.9)+29 = 48.116
    witch is right method???

    By alex r. reonal on 5 October 2017

    my location is oas, albay with latitude of 13.1739deg longtitude 123.4159 deg

    By DJ on 30 June 2018

    the second one, as the above mentions the second formulation is more precise but depends on the season.

    By tabaray alam badhusha on 14 November 2018

    2nd method is right

    By Vietky on 5 March 2017

    Annual 0.76*latitute+3,1
    Winter 0.89*latitute+24
    Summer 0.92*latitute-24.3
    Others 0.98*latitute-2,3

    By opeyemi gbogi on 3 April 2017

    please my latitude is 8.136
    using the methods it gives me 36.3224 and -16.1776
    is this correct

    By hasen on 29 April 2017

    My Lat is -20.2 and Long is 57.5
    By using your method 1 gives me -20°+15° = -5° and -20° -15° = -35°
    Is it correct?

    By nisar samad on 3 July 2017

    hi how u doing
    my latitude is 26.1299
    and longitude is 50.55
    i need to know what is the best angle for yearly production ,i want a fixed structure not move able.
    please guide me

    By alex r. reonal on 5 October 2017

    I’mplanning to use a permanent angle of inclination if facing southby multiplying the latitude by .812

    By arun on 27 September 2017

    which calcuate fix angle summer and winter who donot distrup the panel

    By Kevin on 6 December 2017

    For optimum tilt angles during spring and fall, 2.5° is subtracted from the latitude.
    What formula do you subtract this from? winter or summer

    By Vijay Ganesh on 13 December 2017

    Dear Friends,
    In case of permanent fixing Solar panels on the stand means,
    what ll be the Angle…??

    By C.SHUNMUGHASUNDARAM Shanlee on 8 August 2018

    Excellent., Thank you for posting.
    Neat and clear.

    By Pieter on 1 September 2018

    Easy and excellent! Thanks

    By tabaray alam badhusha on 14 November 2018

    In my site we are using the fixed tilt module mounting structure,by using inclinometer we get 13.5 degree tilt angle in all season(it’s fixed).In manual method how to calculate the tilt angle.(my site is kurnool-andhrapradesh-india)

    Leave a Reply