What effect does tilt angle have on solar panels?

What effect does tilt angle have on solar panels?

HI this is Amy from the altE Store. We’ve
shown you videos already on the effect of shading on solar panels, and effect of the direction
you point your panels, now we are going to show you the effect of tilting your panels.
Now the angle that you select to mount your panels will depend on a few different things.
If you have got just a straight grid tie system that is going to be on your roof and your
roof it a normal average tilted roof, you’re really just going to put it on that, because
chasing after every little last angle on a grid tie system quite often isn’t worth
the extra money. But, if you’ve got an off-grid system, and you need to pull out every single
watt hour you can out of the system, then angle really does come into play, quite significantly.
So I’m going to show you the effect of what we’ve got here. So it is November 20, very
close to the winter equinox, so the sun is very low in the sky. I’m in Massachusetts,
so my angle up here, my latitude is 42 degrees. So if I want to maximize year round performance,
I would want to set my panels at as close as possible to 42 degrees, because if you
figure it’s going to be that, the sun is going to be that angle in the spring and the fall,
as opposed to in the summer when it’s just going to be really high, or in the winter
when it’s going to be very low. So you really need to figure out when you will be maximizing
it. Do you have a winter hunting cabin that you need to maximize your winter, or a year
round place, in that case, you’d want to put them at bit of a steeper angle to try to get
as much power as you can during the short winter days. If you just have a summer camp,
you’re going to have it really up very high. If you’ve got an RV that you are just driving
around with, odds are pretty good that if you just put it flat on the top of your roof,
you’re going to be great, because you are probably going to be using it in the summer
when the sun is the highest. So let’s actually see what affect this has. Now again, I’m at
42 degrees latitude in November, so I’ve got this at just over 50 degree angle. So I’m
really pointing directly at the sun. Now you see up here, I’ve also got a meter, it’s an
insolation meter, so it’s showing me the intensity of the sun. Solar panels are rated at the
standard test conditions, which is 1000 watts per square meter. So right now at quarter
of two in the afternoon, I’m almost at 900 watts per square meter. So I’ve got pretty
good intense sunlight right now. And so I’m going to show you the volts and the amps.
So my volts right now is 19.8 volts and my amps is .41 amps. So you know I’ve got little
5 watt panels, so they are going to be fairly low. But you are going to see a pretty dramatic
change here in the amps, but not so much on the volts. If you saw the other videos you’ll
see that intensity of the sunlight doesn’t affect volts as much as it affects amps, and
that’s true with most semiconductors. So I’m going to change my angle here. So I’ve got
it at 35 degrees now. My insolation has dropped down to 712, by volts is still pretty high
at 19.6, but my amps have dropped down to .34. Now if I go down a bit more here, now
I’m at 20 degrees, which would be great in the summer, but November 20? Not so good.
My insolation’s down to 500 and something, 540, my volts is still, again, still fine
at 19.4 volts, but my amps has dropped almost in half to .27 amps. If I drop down even further,
so I’m pretty much flat, so this is something you’d see probably on an RV, my insolation
is dropped down to 267 watts per square meter. My volts is still ok, it’s 18.8 volts, but
my amps is .15 amps, so I’m really not getting much power out of these panel. So you really
can see that the angle that you tilt them does matter. So if you’ve got an off grid
system, you might want to do something that you can have them adjustable angles, so that
you can have it so that in the winter you are going to have it pretty steep, and in
the summer you are going to have it pretty shallow. Now again, if you’ve got a grid tie
system, quite often it isn’t worth it because the year round average is going to average
out to be alright. But if you have got an off grid system where you really need to keep
those batteries charged up in the winter, having an adjustable system is a great idea.
We can actually combine a couple of these demos that we did and if you have a tracking
system, a dual axis tracking system that will actually follow the sun during the day , and
change its angle throughout the year, that gives you the best of both worlds. So that
would really greatly increase your output, but does add a lot of expense and mechanical
capabilities to your system. So it is something you really need to take a look at, does it
make sense to be chasing after every little bit, could you just make up for the less than
perfect conditions by putting some more solar panels on. So that’s a bit of a balance. So
I hope this helped you understand what angle does. If you liked this, give us a like and
a share, and subscribe to our channel so we’ll notify you when we have more videos coming
out. And go to our website altEstore.com, where we’ve been making renewable do-able
since 1999.


  • Bobby's Solar Homestead says:

    Solar tracking was worth it when pv was 10+ bucks a watt. Not tho with pv 1 or so bucks a watt it's not worth all the trouble.

  • bill767667 says:

    great video Amy thanks I think I'll look into one that tracks,and tilts,will try to make one my self.

  • Solar Service Guy says:

    Great video, and the big problem is the brackets in the market that you need to adjust your panels is crazy money, so you do what you can do until someone comes up with one that is affordable. I also will add your solar power video to http://SolarServiceGuy.com thanks.

  • Aleneski Kalashnikova says:

    Very informative. I learned some.

  • onecrazywheel says:

    Amy, I've got a 2500 watt system with 11 panels. 6 are at a correct 30 degree angle and 5 panels are at about a 10 degree angle. They are all in series. Would it be worth changing the 5 solar panels to match the other 6? We live in Central Florida.


  • onecrazywheel says:

    +altE Store It is a 2500 watt rated Kaco Blue Planet Inverter. With it being a 2500 watt system it is maxed out with the inverter.

  • Gretha Salvador says:

    so that is why.. thanks for this information… very helpful..

  • Artjoms Pugacovs says:

    Now we have to buy solar panels that can receive sun rays in wider angle.

  • Roger Fries says:

    Video Request: Hi, Thanks for all of the great videos! I have three 300 watt Solar World panels on my RV that I recently purchased from you on my RV. RV use is obviously a off grid configuration, but this RV spends most of it's time parked behind my house. How could I use this to keep my battery's charged, but send the excess power into the house to give me some free watts off my electric bill?

  • robert retka says:

    Panel of angle incidence is an important issue, actually the achilles heel of solar panel power conversion .
    The most available solar energy is just for @ 5 hours per day, hopefully it's not cloudy. It is best to keep the angle of incidence at 90 deg. in both the X and Y planes. But then you are going to need a dedicated programmable controller that can readjust the tracking angles automatically. altE can you tell us the cost of such a system and if it may be problematic to mechanical issues? Yes?

  • David Grove says:

    Thanks Amy! Solar Queen!

  • John Chapman says:

    Does angle adjustment have any effect during cloudy weather?
    My installation is in southern England where 40 degrees angle is suggested. My top roof with twelve panels is 30 degrees and my lower roof with two panels is 20 degrees showing a very noticeable difference in output between the two. At optimum angle the output should be 3.78kW max but I only get 3.2kW max in practise. Your advice for domestic roof installations is echoed by my supplier, lay parallel to obviate wind damage.
    Great demo and well presented, thank you.

  • Indonesian FriedRice says:

    thank you…. really informative…

  • Greg Scott says:

    If you have limited roof area, you will get more total energy over the course of the year by laying them flat on the roof. The setback that you need to avoid shadowing will negate any additional energy you get by tilting the panels.

  • Brian 43125 says:

    45 seems to work good in Ohio.

  • Al Ford says:

    If you are on Time Of Day rates, a summer inclination might be better.

  • ROY SJOBLOM says:

    Very good info

  • highflow highflow says:

    and there comes motorised systems handy, you can use those motors from satelite disks, the bigger ones are pretty strong for several tons to lift.

  • JUNNO MARTEN says:

    I would like to make adjustable solar plant prototype for school project, please help me, can i use sensors to adjust the maximum angle for solar panel ? respond to my email. [email protected]

  • Dennis Peet says:

    check out the solar time tracker its nice

  • Inverted Hover says:

    Thumbs up for Massachusetts!

  • Wadley225 says:

    When it comes to tech stuff like this, I just can't take it as seriously, coming from a woman…..

  • Bill Thomson says:

    The correct terms are Voltage and Current. (measured in Volts and Amps)

  • John Keepin says:

    Interesting demonstration, but typical house roof mounted panels inevitably tend to have the same level as the roof it's mounted on (unless they are being mounted on flat roofs with suitable framework). It's now 4 years since I had a system installed on my house, and one of the factors that isn't mentioned here is the effect of panel temperature. They all suffer from reduced efficiency as the temperature rises, unfortunately, so around the Summer solstice, the temp is often the limiting factor, even though the sunshine hours are around the maximum. At my place, the daily max is around 3 kWh at Winter solstice, and around 12 kWh in the Summer if it's a clear blue sky day.

  • ιωαννης τσαπαρας says:

    Thanks God i found your so analytically videos.I was ready for tomorrow to by the so expensive deep cycle batteries and pure inverter for the safety of desktop.Now i will see very carefully all your very professionally videos . You mast bee a teacher. thank you God bless you..

  • Alfred Newman says:

    Winter equinox ?????
    Never heard of it

  • Alfred Newman says:

    I have a piece of PVC pipe mounted to the side
    Every other week at high noon I tilt my panels until I get no shadow from the pipe

  • Figglebob High says:

    can someone give me the link to the watt/m² reader she has?

  • Electric Engineer says:

    Awesome demonstration,you are the best

  • tank zappa says:

    Wow yurt stupid with cracked voice and hand flapping…obnoxious

  • American Bluejacket says:

    Thank You for the video. It was very informative concerning angle of panel to the sun. I had not seen it done this way where there is cause and effect registered instantaneously. Very good. I will be watching more of your videos.

  • pyronmasters says:

    Huge difference, I have two 325w panels, four 6v 225ah batteries hooked up to a chest freezer, when the compressor was on, the batteries dropped to 12.4v(panels at 30° angle), with the "Solar Tilt" app (Playstore) I found the new angle 41° voltage stays at 13v now with the compressor on.

  • hijwo mark says:

    Thanks your efforts Ma'am ,very useful video .keep going

  • Ric777888 says:

    had no idea angles mattered so much.

  • Passed High School Physics says:

    Very nice video. At (0:55) you mean winter solstice not winter equinox.

  • Ayush Amrit says:

    Thanks for information

  • Wallabynge says:

    When the angle of the sun is steep, the panels get cooler, which enhances the output. This demo won't show panels cooling down. However, the glass becomes more reflective.
    I believe the output is pretty close to the cosine of the incident angle:
    0 degrees = 1
    10 degrees = 0.985
    20 degrees = 0.94
    30 degrees = 0.866
    40 degrees = 0.766
    45 degrees = 0.7
    50 degrees = 0.64
    60 degrees = 0.5

  • Maree rogers says:

    Like your angles IV been watching mynes as early daylight and is very shaded I've two off grid one is ok and a bigger is showing signs from portable set up , what inverter, so the mppt is slack and battery amp slack do one of these doesn't set to charge battery as I liked but crashes alot , I've the amp wires to track if batteries r alright it is slow but will test it this way and did consult angle solar panel ,, to remove sun's rays going alot over where roof is and been 30 minutes just when it's windy days etc there's alot change so when it's hot full on it can also but most sun rays are in the aim of angles , as natural lightness be solar DC , and couple more things to look at inverter and charge controller as panel is supposed to be set in angle therefore it is one problem the inverter has is it beeps alot so no way of telling what's not or is doing the continued power in turn the system was shut down I turn on and it either dead or runs till nothing suppose to know something I knew nothing till almost a year ago frustrates the high thing we all try free power just didn't know it works out so trying angle it works out 60 amp and at times you get 6 minutes or 6 seconds

  • cgwworldministries says:

    I do not have mine at a tilt, they sit flat on my RV and they work great even in the winter. Just gotta keep them cleaned off.

  • Dennis Jemison says:

    Love all The INFORMATIONAL Video's This Channel Puts Out…God Bless…Amen

  • Commando602 says:

    Great hair!

  • Zoltan Szabatin says:

    My question not connected to this video,….can I connect my car(RV) generator(altarnator) to my solar charge controller ¿?

  • James Vaughan says:

    I was thinking about this. didn't think it would make such a big difference. thanks!

  • Mohmed Hesham says:

    Thanks Amy 🙂

  • Boberek4 says:

    Thanks, great video, regards from Poland

  • Asim khan says:

    Hi Ammy. I'm looking for a diy single axis sun tracking circuit which can controll linea actuator, simple circuit which I can make my own. Thanks Amy for the informative videos.

  • Asim khan says:

    My email is [email protected] and my Whatsapp no is 92-3212011998

  • Kully_Exo_Vtec says:

    Perfectly answered my head scratcher about why my 310w panel on my flat roof is hardly doing anything!! 🙏🏽

  • Roger and Lynda Beall says:

    God I love a Woman Who knows her I2R

  • Roger and Lynda Beall says:

    Now panels ar cheap, angle doesnt matter, just put up more panels, cheaper than tracking system.'

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