solar panel orientation
- Thread starter doox00
- Start date
I did.I thought he meant like landscape vs. portraitwho knows?!
Stick them at a 37.5 degree rotation.
When you get asked why, tell them it is to capture the sun's rays better in the winter, counteracting the rotation of the earth, just to mess with people's minds.
Or I guess you might get looked at like you're a little cooked.
When you get asked why, tell them it is to capture the sun's rays better in the winter, counteracting the rotation of the earth, just to mess with people's minds.
Or I guess you might get looked at like you're a little cooked.
littleharbor2
Solar Wizard
The newer Perc half cell panels are basically two panels in one. These type panels are meant to be positioned in the upright, "portrait" position. If shadows tend to creep up on a panel this positioning will allow the upper half of the panel to be unaffected. Theoretically giving better output.
sunshine_eggo
Victron's little biatch
If shading is a factor, orientation matters.
A portrait oriented panel can have 100% of its output cut off if ONE entire ROW of cells is shaded. If columns are shaded, panel output will be cut by 1/3 when a single column of cells is shaded. Once the entire 1/3 of the panel is shaded, the next full column of cells shaded will take out the next 1/3, etc.
In landscape, the behavior is the same except swap rows and columns.
In other words:
If you have shading across your panels, if it comes in from the side, portrait will result in more production.
If you have shading that creeps in from the top or the bottom of the array, landscape is best.
Here's an example:
Most important take-away in all this babble?
Shade destroys PV performance.
Get a chainsaw and eliminate the shading.
A portrait oriented panel can have 100% of its output cut off if ONE entire ROW of cells is shaded. If columns are shaded, panel output will be cut by 1/3 when a single column of cells is shaded. Once the entire 1/3 of the panel is shaded, the next full column of cells shaded will take out the next 1/3, etc.
In landscape, the behavior is the same except swap rows and columns.
In other words:
If you have shading across your panels, if it comes in from the side, portrait will result in more production.
If you have shading that creeps in from the top or the bottom of the array, landscape is best.
Here's an example:
Most important take-away in all this babble?
Shade destroys PV performance.
Get a chainsaw and eliminate the shading.
EcoWorthy Bryce
Ecoworthy Ambassador
Why should the best angle be latitude plus 15 deg? wanna know more about this...
littleharbor2
Solar Wizard
In a nutshell, because the earth tilts, seasonally.
In other words, the sun is lower (closer to the horizon) in winter than summer.
And this increases the further you are from the equator.
Edit: in the summer it's latitude Minus 15 deg. So, for me 45 - 15 = 30deg, so closer to horizontal since the sun is higher.
And in the spring and fall it's just latitude with no correction.
And this increases the further you are from the equator.
Edit: in the summer it's latitude Minus 15 deg. So, for me 45 - 15 = 30deg, so closer to horizontal since the sun is higher.
And in the spring and fall it's just latitude with no correction.
Last edited:
Seems to be different ways to calculate.
Here are a few examples:
savvycalculator.com
footprinthero.com
solarsena.com
Here are a few examples:
Solar Tilt Calculator - Savvy Calculator
Maximize solar panel efficiency with our Solar Tilt Calculator. Find your optimal tilt angle for enhanced energy production.
savvycalculator.com
Solar Panel Tilt Angle Calculator - Footprint Hero
Calculate the best tilt angle for your solar panels based on your location (address, city, or zip code) with our free solar panel tilt angle calculator.
footprinthero.com
Optimal Solar Panel Tilt Angle Calculator - SolarSena
The solar tilt angle calculator allows you to calculate the optimal angle for fixed, twice adjusted, seasonally adjusted, monthly adjusted solar panels.
solarsena.com
chrisski
Solar Boondocker
The tilt calculator will find the best angle overall for max production.
This could be a little different if you need more power in one season, say summer for air conditioner and don't use the place in the winter or vice versa. The one calculator in my signature block is one that will give a monthly graph and you can ajust angles to see how that effects production for the month.
This could be a little different if you need more power in one season, say summer for air conditioner and don't use the place in the winter or vice versa. The one calculator in my signature block is one that will give a monthly graph and you can ajust angles to see how that effects production for the month.
I wonder why more installations don't have landscape orientation since most shading I see creeps from bottom to top. Might have something to do with more holes in the roof or longer mounting rails.If you have shading that creeps in from the top or the bottom of the array, landscape is best.
Here's an example:
ricardocello
Watching and Learning
Unless the trees are on the neighbor's land. Then you need to be tactful.Get a chainsaw and eliminate the shading.
chrisski
Solar Boondocker
The worst tree problems I see are the ones from the HOA. A south facing roof at the adage of the HOA with Palm trees that have grown 40’ high over the years since the installation. I wonder what the winter production is on those.
OffGridInTheCity
Solar Wizard
I use PVWatts - https://pvwatts.nrel.gov/pvwatts.php - and play with azimuth and angle to see the affect on PV output. It's *significant* thru a year to me.
As an example, I have excess in spring/summer but woefully lacking in Dec, so I'm planning to mount 2.4kw vertically on a fence but I could do 85deg vs 90deg for example. So I use pvwatts to see 85deg vs 90deg.
As another example, I'm full of panels (south roof and yard array) but have a west facing roof still available and it was startling to see how dismal the production would be in Dec for the effort/$ - better to do 90deg on the south facing fence above.
As an example, I have excess in spring/summer but woefully lacking in Dec, so I'm planning to mount 2.4kw vertically on a fence but I could do 85deg vs 90deg for example. So I use pvwatts to see 85deg vs 90deg.
As another example, I'm full of panels (south roof and yard array) but have a west facing roof still available and it was startling to see how dismal the production would be in Dec for the effort/$ - better to do 90deg on the south facing fence above.
This is why my panels are landscape, in winter, there is shading on the top row, and I only lose a little bit of power instead of the entire row.If you have shading across your panels, if it comes in from the side, portrait will result in more production.
If you have shading that creeps in from the top or the bottom of the array, landscape is best.
Here's an example:
View attachment 184340
sunshine_eggo
Victron's little biatch
According to this guy, it's closer to 20°, and I tend to agree with him.
Fixed.
Same except mine is on the bottom. Panels are mounted on a shipping container, and I get some early morning treetop shading across the bottom landscape row of cells. The "trees" here are junipers and pinon pines - more like 10-20' tall large bushes.
Yesterday was winter solstice, and any shading didn't seem to make much difference...
2970W (2475W, 83% peak observed)
29° tilt
15.4kWh harvested
5.2 hours insolation
zanydroid
Solar Wizard
Having the short edge parallel to rails minimizes cost.
There are various reasons why having the rails go parallel to the roof line is better. Though you are definitely allowed to go perpendicular. And this will help somewhat reduce rail cost for landscape instal.
Having half cut module internally wired as 2P3S makes portrait work better. Because this means shading parallel to the roof will only block one of the halves.
Landscape is OK but never hang the panel upside down! All the electricity will fall out and pool on the ground. Shock hazard.
littleharbor2
Solar Wizard
I would think whatever it should be, Mid winter and mid summer would be a good average. There's a great app called "Solar Tilt" that you can choose any day of the year at your location, or any chosen location,. Picking the longest day or shortest day is only going to be correct on those days. this app has a built in GPS and inclinometer that you can use by setting the long edge of your phone on the face of the panel for pretty accurate angle setting. It's a free app. I highly recommend it.
Thanks for that. Just downloaded and added to my solar tools group on my phone!
Does that hold true for our members in the southern hemisphere?
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