# Solar panel orientation question



## Danaus29 (Sep 12, 2005)

New solar installation is the trend in my area. I'm thrilled some people are able to take advantage of solar and the 26% tax credit. I can't. My roof is heavily shaded by trees for more than half the day, even in the winter. To make it worth my time, 4 very lovely trees on neighboring properties would have to be taken down. I'm not going to ask for that, besides, I like the trees.

Anyway, my question, for those who have actual experience in solar production; is it worthwhile to install panels on the north side of a roof? The roof in question does get some angled sunshine. It had a little bit this morning. But would it be enough to make the cost worthwhile?

I would post pictures but it isn't my house. The roof is gently sloped, less than 45°. The house isn't directly facing north but is at a very slight angle with the east side a couple feet more northward than the west side. House in question is about 30 feet wide, 50 feet long.

Just idle curiosity. I'm not the one paying for the installation. And I am not considering getting solar from this installer, or any other, any time in the forseeable future.

Thanks for the info.


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## ET1 SS (Oct 22, 2005)

Danaus29 said:


> ... is it worthwhile to install panels on the north side of a roof?


That is hard to say.

I suggest that you ask one of your local installers for a quote. They will measure your roof and use their formulas to predict how much power you can generate.

Only after knowing how much power could be generated, only then can anyone estimate if the install is 'worthy' doing.


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## Danaus29 (Sep 12, 2005)

Our roof has been looked at for installation a few times, by 3 different installers. No, my roof is not a good choice for solar unless those trees are removed. Wasn't my roof I was asking about anyway. It's the roof of the house across the street. After watching the past couple hours it looks like they are assembling the panels on the north side prior to installing them on the south side. There is sun on the part of the roof in question now. It gets a lot more sun than I realized.

I now see I wasn't clear in my original post. Sorry.


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## RJ2019 (Aug 27, 2019)

I know it isn't what you asked, but solar doesn't have to be installed on a roof. If you have a bit of space they could be located in a sunnier spot.
As far as orienting them north, I've never heard of it. Maybe in the southern hemisphere?


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## Digitalis (Aug 20, 2021)

Danaus29 said:


> is it worthwhile to install panels on the north side of a roof?


It is in Australia


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## Danaus29 (Sep 12, 2005)

RJ2019 said:


> I know it isn't what you asked, but solar doesn't have to be installed on a roof. If you have a bit of space they could be located in a sunnier spot.
> As far as orienting them north, I've never heard of it. Maybe in the southern hemisphere?


I'm at the top of a northern slope. There's only a couple spots in my back yard where I get enough sun to plant tomatoes. I suppose I could have my monstrous sycamore tree removed but it isn't dead and neither am I, so it stays as long as we both live here.


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## MichaelK! (Oct 22, 2010)

The sun will be hitting those North-facing panels at a very acute angle, sort of like south-facing panels right at 7:00AM, so I'd guestimate they would be putting out around 5-10% of their rated output. If your source of panels is very cheap, and you have no other space, it potentially could make some power, but not as much as you would hope.


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## altair (Jul 23, 2011)

When we looked into solar, they sent a tech over to do an overview. He had a device (drone? I wasn't present, so I don't know) which measured the angle and estimated output. You could look into that for a better idea and likely won't get charged a dime for a quote/look see.


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## Danaus29 (Sep 12, 2005)

The team they have out here now took a bunch of pictures and measurements before giving the home owners any quotes. I don't know if they used a drone. When we looked into it years ago the installers used sattelite images.

The whole set-up is costing upwards of $40,000 on these homes. They will get a bit over $10,000 back in tax refunds. This is the last year for the 26% tax credit.

The crew is assembling the panels on the north side. The panels are being installed on the south facing slope of the roof.


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## Fishindude (May 19, 2015)

Why bother with solar panels if you can't set them up to be as efficient as possible?
North slope sounds like a bad idea.

Anyplace you can put them on racks in the yard and keep them off the roof?


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## Danaus29 (Sep 12, 2005)

Fishindude said:


> Why bother with solar panels if you can't set them up to be as efficient as possible?
> North slope sounds like a bad idea.
> 
> Anyplace you can put them on racks in the yard and keep them off the roof?


At my house? No. 

The installers have left for the day with one assembled panel on the north slope of the *NEIGHBOR'S* roof. I'll update if they move it to the south slope. 

I was just mildly curious as if the north was a permanent location. I didn't watch them assemble the previously installed panels.


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## doc- (Jun 26, 2015)

Optimum output is when the panels are perpendicular to the sun's rays. That angle changes with the hour & with the seasons, so the best compromise is to do it for the spring & fall solstices at noon.....The output falls off drastically as you get away from that optimum....Unless you live in the Sun Belt, you probably only get about 25% of the rated power (Eg- a 1kW panel will only give you 250 W averaged over the year.

You can mount them on the north side of the roof, but have to slant them so they face south--That's a lot of derrick work, and if a strong wind comes from the north, you won't stay in Kansas for very long, Dorothy.


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## Digitalis (Aug 20, 2021)

This reminds me of a folktale about "The Wise Men of Chelm," where the town decided to invest in building a water mill to bring prosperity to their poor town. As they were preparing to build someone commented that it was a shame that such a glorious creation was to be hidden down in the valley, so they discussed and decided to build the water mill on a hilltop where it would be visible to all around!


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## Danaus29 (Sep 12, 2005)

I'm going to type this part slowly. Maybe I wasn't clear, maybe it's being missed. I don't know. By typing it slowly maybe I'll get a chance to read it before I hit the post button. 

I am not installing solar. I do not get enough sun anywhere on my property for a good siting for solar panels. This installation is on the house across the street. When I first looked at it this morning, it looked like they were installing panels on the north slope. I realized later, and posted it, that the panels are being assembled on the north slope and being set up on the south slope. My mistake. If I wasn't busy trying to get stuff done on my property I would have spent time watching the assembly and installation.


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## backwoodsman7 (Mar 22, 2007)

Danaus29 said:


> I'm going to type this part slowly. Maybe I wasn't clear, maybe it's being missed. I don't know. By typing it slowly maybe I'll get a chance to read it before I hit the post button.


You were very clear. I think maybe a lot of folks just read way too fast and miss a lot of details, or type a reply to the post they just read without reading the rest of the thread first.

But thank you for typing slowly. It's a big help to those of us who are slow readers.


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## RJ2019 (Aug 27, 2019)

Danaus29 said:


> I'm going to type this part slowly. Maybe I wasn't clear, maybe it's being missed. I don't know. By typing it slowly maybe I'll get a chance to read it before I hit the post button.
> 
> I am not installing solar. I do not get enough sun anywhere on my property for a good siting for solar panels. This installation is on the house across the street. When I first looked at it this morning, it looked like they were installing panels on the north slope. I realized later, and posted it, that the panels are being assembled on the north slope and being set up on the south slope. My mistake. If I wasn't busy trying to get stuff done on my property I would have spent time watching the assembly and installation.


Got it! Thanks for clarifying, I can be a bit dense at times😂


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## Digitalis (Aug 20, 2021)

Danaus29 said:


> I'm going to type this part slowly. Maybe I wasn't clear, maybe it's being missed. I don't know. By typing it slowly maybe I'll get a chance to read it before I hit the post button.
> 
> I am not installing solar. I do not get enough sun anywhere on my property for a good siting for solar panels. This installation is on the house across the street. When I first looked at it this morning, it looked like they were installing panels on the north slope. I realized later, and posted it, that the panels are being assembled on the north slope and being set up on the south slope. My mistake. If I wasn't busy trying to get stuff done on my property I would have spent time watching the assembly and installation.


While I did have fun with my replies, and in the vast majority of North American projects it wouldn't make sense, it actually is a valid question that depends on several factors:

latitude: closer to the equator = less penalty for wrong roof slope
roof pitch: closer to flat = less penalty
panel cost: these have dropped dramatically and the cheaper they get the more it makes sense to install at suboptimal angles
grid electric cost: higher rates make suboptimal installations more profitable

At the end of the day every potential project requires some evaluation to see if it makes financial sense.


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## Danaus29 (Sep 12, 2005)

It's been 2 days since the neighbor's solar installers left. There is one 3 section panel on the north slope of the roof. I guess that is it's permanent spot.

I'm still waiting to hear how this is working out for another neighbor. They are waiting for the inspector, electrician and electric company to finish their work before the system can be put into use.


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## Hard Aground (Oct 4, 2020)

Late to this thread, but I wanted to share these observations with those who are interested in solar power. As I was exploring Cochise Stronghold one day, I saw a camping rig with hinged panels on top, and the driver merely oriented the rig toward the sun before flipping up the panels. Thought that was a great idea, and the driver said he always had enough power for the things he was running off the system.  

When searching listings for off-grid properties in northeastern Arizona, I saw one home which had the panels mounted on a swiveling metal framework some short distance from the home itself... the owner would simply turn the panels toward the sun in the morning, rotate 'em in the afternoon. The slightly remote location of the panels offered more sunshine, no interference from trees on the property. Just my $.02, I thought both setups were pretty cool.


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## Danaus29 (Sep 12, 2005)

I've read about those rotating set-ups. They are much more efficient than fixed panels.


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## DahliaSmith (15 d ago)

Thanks for your question! While the north side of a roof does not get the same amount of direct sunlight as the south side, it can still be a viable option for solar installation. It is important to consider the angle of the roof, the size of the roof, and the amount of sunlight it receives. The best way to determine if a north-facing roof is suitable for solar energy is to get a site assessment from a qualified solar installer. I can recommend contacting the guys from Yenex - Discover Distributed Energy. They dealt with my solar system from home. They will be able to tell you if your roof is suitable for solar and how much energy you can expect to generate. Consider the installation, especially if you can take advantage of the 26% tax credit. Good luck!


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## Montanarchist (Feb 24, 2005)

Another important aspect that I don't know was mentioned is your latitude and when you'll want the power. Here in Montana, in the summer, a northern aspect array will make plenty of power but hardly any or none in the winter. Good if you have a summer cabin, horrible of you'll be in it in the winter.


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## doc- (Jun 26, 2015)

Exactly.

Let's say, for easy artihmetic, that one lives 45degN, and the north facing side of the roof is 45deg too, facing away from the sun, and the panels are mounted flush with the roof.... The sine of 45deg is 0.707....That means at noon in the middle of summer and no clouds in the sky (sun directly over head-- the best day of the year for generating power, you'll get only 70.7% of the power rating of your panels...You'd need 10 panels to give you the production of 7 panels mounted on the south side....Subtract even more for clouds and hours other than 12 noon.

... and in winter when the sun gets no higher than 45deg at noon, you'll get exactly zero production no matter how many panels you have. The sun's rays will be exactly parallel to the face of the panels at noon and in the shade below the peak of the roof at other hours.

BTW, Danaus-- tell those neighbors to send all us tax payers the thank you notes we deserve for working so hard to pay their bills, those leeches.


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## Danaus29 (Sep 12, 2005)

doc- said:


> BTW, Danaus-- tell those neighbors to send all us tax payers the thank you notes we deserve for working so hard to pay their bills, those leeches.


One won't get any tax credits as they pay no income taxes. Both the others also spent a lot of money to replace siding and insulate their houses. None of them get huge child tax or earned income credits.


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