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.
Bruce Domer
By

Bruce Domer

on 27 Jul 2020

I am at about 42 degrees North, at summer solstice, the sun appears to be north of the north facing outside wall of my house. As the earth nears noon, not sure exactly when it happens, the sun no long shines on the north wall. It didn't make sense to place the solar panels the same as my latitude. These two methods make more sense though I have not looked into calculating the best angle. I have considered creating a system that will rotate the panel so that the panel face will be normal to the sun at all times, but haven't come up with one. Did not spend much time looking into it. Does anyone have a fairly simple way to rotate solar panels to best use the sun's light energy? Tilted at my latitude makes the face normal to the sunlight at only one time per year, summer solstice.

Brian Shingleton
By

Brian Shingleton

on 08 Oct 2020

Hi Bruce. I am currently developing a simpler than turntable to do exactly this. I was inspired by always having to move my portable panel to face the sun when camping using the panel to keep the leisure battery charged. I have built prototypes successfully and now embarking on the final production product. Watch this space! Brian

Brett
By

Brett

on 08 Oct 2020

Interested to learn more Brian

david aponte
By

david aponte

on 15 Oct 2020

I faced the same problem, what I made for improve efficiency is: 1. Installing an actuator tied to a servomotor and PLC with a radiaton sensor, which reads the instant radiation and corrects the lenght to angle of the panel to a maximum value with a PID cheap control ( arduino)

ras
By

ras

on 16 Nov 2020

I made a frame from bed rails ( angle iron type ) I placed a steel tek 1 1/4\" 90 swivel socket about 12\" from top 36\" wide by 64\" long and put a 7\' 1 1/4 pipe in ground and mounted the frame mine is for six panels but you could do 4 the swivel has a lock nut for rotation but you have to put a collar for bottom adjustment arms let me know and I can send pictures

shaharyar
By

shaharyar

on 25 Dec 2020

Now in modern world solar tracker are using for solving this type of issue because they having a feature to move and track a sun ray

Felix
By

Felix

on 30 Apr 2021

Sun tracker is your ultimate solution. You don\'t have to be there to adjust all the time..

Black_whale
By

Black_whale

on 12 Jul 2020

What about algeria

korosh
By

korosh

on 09 May 2020

θ=(1/4 rad)/(sec⁡〖with respect to the spaceraft 〗 if) ω is the absolute angular velocity of Th solar panels determine ω is the absolute angular velocity of the solar panels etermine ω.also find the acceleration of point a when θ= 30° Ans. ω =1/ö I rad/sec² Aa=0.313i-2.43j-01083k ft/ sec²? θ=(1/4 rad)/(sec⁡〖with respect to the spaceraft 〗 if) ω is the absolute angular velocity of Th solar panels determine ω is the absolute angular velocity of the solar panels etermine ω.also find the acceleration of point a when θ= 30° Ans. ω =1/

Eva
By

Eva

on 25 Sep 2019

Why do you use 15? How was this number found?

Jon
By

Jon

on 22 Aug 2019

"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." Solar panels do not need heat they need the most direct exposure to sunlight.

ATUL SHAH
By

ATUL SHAH

on 02 Jul 2019

Maximum output per kilo watt per day if south facing panel,8 hr continued sun light. Panel slop 20 degree

ramu
By

ramu

on 26 Jun 2019

how calculate ap latitude

Alwielland Bello
By

Alwielland Bello

on 08 May 2019

What is your basis for both methods?

tabaray alam badhusha
By

tabaray alam badhusha

on 14 Nov 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)

Pieter
By

Pieter

on 01 Sep 2018

Easy and excellent! Thanks

C.SHUNMUGHASUNDARAM Shanlee
By

C.SHUNMUGHASUNDARAM Shanlee

on 08 Aug 2018

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

Vijay Ganesh
By

Vijay Ganesh

on 13 Dec 2017

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

Kevin
By

Kevin

on 06 Dec 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

arun
By

arun

on 27 Sep 2017

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

nisar samad
By

nisar samad

on 03 Jul 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

alex r. reonal
By

alex r. reonal

on 05 Oct 2017

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

hasen
By

hasen

on 29 Apr 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?

opeyemi gbogi
By

opeyemi gbogi

on 03 Apr 2017

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

Vietky
By

Vietky

on 05 Mar 2017

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

ramkripal
By

ramkripal

on 30 Dec 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??? 😐😐😐

tabaray alam badhusha
By

tabaray alam badhusha

on 14 Nov 2018

2nd method is right

DJ
By

DJ

on 30 Jun 2018

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

alex r. reonal
By

alex r. reonal

on 05 Oct 2017

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

Maxim
By

Maxim

on 14 Dec 2016

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

alex r. reonal
By

alex r. reonal

on 05 Oct 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

Harilal Bhatti
By

Harilal Bhatti

on 24 May 2016

Very Easy to Understand

ishaq
By

ishaq

on 09 Jun 2019

my latitude is 32.7N 67.6E so what is my tilt angal

Abrar Gul peshawar pakistan
By

Abrar Gul peshawar pakistan

on 27 Jan 2020

plz whatsapp me on +92 333 9932015

Amarnath.P
By

Amarnath.P

on 12 Mar 2018

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

FIROSUDHEEN
By

FIROSUDHEEN

on 13 Jul 2021

11.25 * 0.9 +29 for winter and 11.25 * 0.9 - 29 for summer

Raman Patel
By

Raman Patel

on 26 Dec 2017

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

Ken A.
By

Ken A.

on 09 Nov 2020

Rather than due south, I have placed my two arrays off by 15 degrees, so that one is pivoted slightly to the SE and one slightly to the SW, to give me a longer period of charging my off-grid system. Should I adjust the above calculation for tilt of the two arrays?

Robin hood
Engr Shahzad Aslam
By

Engr Shahzad Aslam

on 06 Mar 2021

Simple method is tilt = 90 - Latitude

Launcelyn
By

Launcelyn

on 28 Mar 2021

I\'m planning a 12kW array with battery storage, but we already have a 4kW grid tied array (at 22deg) so I plan to set the panels at the optimum angle for winter, say 60-65deg (as we\'re at lat.52), less a bit to allow autumn and spring to be a bit more productive. With about 36-48 kWh storage I\'m hoping to cover about 10MWh of our total annual consumption of 25-30 MWh. Many thanks for the article giving the various options.

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