DIY solar panel installation on flat portion of roof

[a_scanner_brightly]

My roof is kind of irregular (see attached pic). Project Sunroof says that it might not be ideal, but I'm not willing to give up just yet.

There's a south facing surface that could fit 2-3 panels, but on the east side there's a flat covered patio that could probably fit 8 more panels.

The mounting kit for the 2-3 south-roof panels would just be the standard mounting rails, as that roof is already at about 30 degrees.

The flat covered patio would need a kit that raises the panels a bit and then tilts them to 30 degrees. Anyone have links to a system for this?

I'm planning to buy one of the grid-tie microinverter kits from Blue Pacific Solar
https://www.bluepacificsolar.com/solar-kits.html

[Fishindude]

Mounting solar to a roof is a good way to create some potential roof leaks and will also increase the cost of re-roofing significantly when that occurs.
Put them on a rack in the yard somewhere.

[uniwelder]

If you mounted them over the patio roof, its probably more cost effective overall to just use the available slope than to try tilting them.  According to pvwatts.nrel.gov, south facing panels at 26 30 degrees vertical pitch gives 17% more electricity than east facing panels sitting flat on the roof.  Considering you'd have to space them generously to achieve an ideal south facing pitch without shadowing each other, you'd likely end up with few enough panels and extra cost for racking not to make that worthwhile. 

From the photo with the vehicle as reference, it doesn't look like there's much square footage for panel mounting.  How big are the areas?  You'll want some space around the perimeter to walk around for the install and any troubleshooting too.

--Edited to correct angle typo.  Other numbers remain the same.

edited to add--- I've never played with the Sunroof site before.  Looking at the map of homes around me, it looks really well put together!  I'm surprised how accurate their sun exposure calculation seems to be, considering tree shading, etc.

[a_scanner_brightly]

Mounting solar to a roof is a good way to create some potential roof leaks and will also increase the cost of re-roofing significantly when that occurs.
Put them on a rack in the yard somewhere.

Re: cost of re-roofing, sounds like this means I should rip out what's there and install a metal roof first. Then go with solar panels.

[chemistk]

Mounting solar to a roof is a good way to create some potential roof leaks and will also increase the cost of re-roofing significantly when that occurs.
Put them on a rack in the yard somewhere.

Re: cost of re-roofing, sounds like this means I should rip out what's there and install a metal roof first. Then go with solar panels.

Panels don't always lead to roof leaks, especially if you take the time to make sure that your mounting points are properly sealed. If you're only putting up ~10 panels DIY, you should be able to take them down yourself before re-roofing as well.

We bought a house in July that has 39 panels across 2 banks, installed in 2011, and there are zero leaks nor is there evidence there ever was a leak. In our area, the current cost for a company to unmount and remount our system to accommodate a new roof is around $2500. Not cheap but also not ridiculously expensive either.

[Abe]

We have a similar ratio of East/west vs south roof (but a larger surface area total) and installed mostly on the east and west, with additional panels on the south. The output has been good (55kWh max from a 10kW system). It’s worth tilting the east panels properly.

Agree that roof leaks are rare with proper installation. Make sure mounting brackets are properly sealed and installed per manufacturer instructions and you’ll be fine. https://www.ironridge.com/ is a standard racking system that DIY prefer

[GuitarStv]

Mounting solar to a roof is a good way to create some potential roof leaks and will also increase the cost of re-roofing significantly when that occurs.
Put them on a rack in the yard somewhere.

Re: cost of re-roofing, sounds like this means I should rip out what's there and install a metal roof first. Then go with solar panels.

Panels don't always lead to roof leaks, especially if you take the time to make sure that your mounting points are properly sealed. If you're only putting up ~10 panels DIY, you should be able to take them down yourself before re-roofing as well.

We bought a house in July that has 39 panels across 2 banks, installed in 2011, and there are zero leaks nor is there evidence there ever was a leak. In our area, the current cost for a company to unmount and remount our system to accommodate a new roof is around $2500. Not cheap but also not ridiculously expensive either.

Just another data point, but my solar panels were installed in 2013 on a regular asphalt shingle roof and we've also had zero problems with leaking.

[a_scanner_brightly]

We have a similar ratio of East/west vs south roof (but a larger surface area total) and installed mostly on the east and west, with additional panels on the south. The output has been good (55kWh max from a 10kW system). It’s worth tilting the east panels properly.

Do you have pictures of what this looks like on the east roof? I'm very curious to see more complicated layouts than just panels across the one south facing roof, which is all that's in my neighborhood.

[AO1FireTo]

I'd love to do solar panels on my house, we have a nice south facing roof as well.  The biggest problem I have is DW thinks they are too ugly looking.  Elon Musk had a good idea but they are way too expensive to make sense. 

[monarda]

Also zero problems with our rooftop installation, part in 2011 and expanded in 2019. Thanks for the site, didn't know about that one.

[GuitarStv]

I'd love to do solar panels on my house, we have a nice south facing roof as well.  The biggest problem I have is DW thinks they are too ugly looking.

We had a similar discussion before getting ours.

Probably best to ascertain exactly how much time (in hours) DW spends gazing lovingly at the beauty of your roof in a given year . . . once you've got that number the decision becomes a little more straight forward.   :P

[Fishindude]

Just another data point, but my solar panels were installed in 2013 on a regular asphalt shingle roof and we've also had zero problems with leaking.

Congrats, your roof hasn't leaked yet.   

Ask any builder or roofer and they will tell you that 90% of roof leaks occur at gutters, valleys or "penetrations" thru the membrane.    Penetrations can include; chimneys, vents, skylites, antennas, furnace stacks, etc.   Solar panel systems require a bunch of mounting brackets that require fasteners (penetrations) at each.   Any intelligent roofer or builder will also recommend that you eliminate as much roof mounted stuff and / or penetrations thru the membrane as possible, to assure long and trouble free life out of your roof system.   Every penetration is a potential leak point and every time you set foot on your roof to do anything is an opportunity for damage creating a leak.

I built, repaired and maintained buildings of all types for 40 years and dealt with one heck of a bunch of roof problems.   Just providing some sound advice based on experience, take it or leave it.

[boarder42]

Just another data point, but my solar panels were installed in 2013 on a regular asphalt shingle roof and we've also had zero problems with leaking.

Congrats, your roof hasn't leaked yet.   

Ask any builder or roofer and they will tell you that 90% of roof leaks occur at gutters, valleys or "penetrations" thru the membrane.    Penetrations can include; chimneys, vents, skylites, antennas, furnace stacks, etc.   Solar panel systems require a bunch of mounting brackets that require fasteners (penetrations) at each.   Any intelligent roofer or builder will also recommend that you eliminate as much roof mounted stuff and / or penetrations thru the membrane as possible, to assure long and trouble free life out of your roof system.   Every penetration is a potential leak point and every time you set foot on your roof to do anything is an opportunity for damage creating a leak.

I built, repaired and maintained buildings of all types for 40 years and dealt with one heck of a bunch of roof problems.   Just providing some sound advice based on experience, take it or leave it.

you chime in on every single solar thread with the same exact statements and everyone with solar here is not reporting these issues think seem to be so common

[Fishindude]

you chime in on every single solar thread with the same exact statements and everyone with solar here is not reporting these issues think seem to be so common

Yep.   
Might not be a problem yet, but it will, give it some time and weather.

[uniwelder]

Just another data point, but my solar panels were installed in 2013 on a regular asphalt shingle roof and we've also had zero problems with leaking.

Congrats, your roof hasn't leaked yet.   

Ask any builder or roofer and they will tell you that 90% of roof leaks occur at gutters, valleys or "penetrations" thru the membrane.    Penetrations can include; chimneys, vents, skylites, antennas, furnace stacks, etc.   Solar panel systems require a bunch of mounting brackets that require fasteners (penetrations) at each.   Any intelligent roofer or builder will also recommend that you eliminate as much roof mounted stuff and / or penetrations thru the membrane as possible, to assure long and trouble free life out of your roof system.   Every penetration is a potential leak point and every time you set foot on your roof to do anything is an opportunity for damage creating a leak.

I built, repaired and maintained buildings of all types for 40 years and dealt with one heck of a bunch of roof problems.   Just providing some sound advice based on experience, take it or leave it.

you chime in on every single solar thread with the same exact statements and everyone with solar here is not reporting these issues think seem to be so common

I agree.  Unless you've actually encountered problems with rooftop solar, don't assume.  The penetrations Fishindude is talking about are obstacles where the sealed edge is above the shingle, in the path of water.  When mounting panels, the attachments are fastened under the shingles, so not much different than complaining about all the other thousands of roof penetrations that are made in a shingle roof.  A friend of mine owns a solar installation company and his hundreds of customers haven't complained about roof leaks.

[uniwelder]

We have a similar ratio of East/west vs south roof (but a larger surface area total) and installed mostly on the east and west, with additional panels on the south. The output has been good (55kWh max from a 10kW system). It’s worth tilting the east panels properly.

How are your east panels tilted?  The drawbacks of tilting (shadowing, less panels per roof sq ft, complex racking system) are usually much greater than their benefit on a roof.

[Abe]

We have a similar ratio of East/west vs south roof (but a larger surface area total) and installed mostly on the east and west, with additional panels on the south. The output has been good (55kWh max from a 10kW system). It’s worth tilting the east panels properly.

Do you have pictures of what this looks like on the east roof? I'm very curious to see more complicated layouts than just panels across the one south facing roof, which is all that's in my neighborhood.

Here’s the photo with the panel layout. Regarding tilting: our roof slope was actually close to perfect so they didn’t have to do much for mounting the panels on any side (just the standard racks).

I have a journal here that shows some of the resulting output curves. It’s called solar installation journal or something original like that. The picture below is from noon, so the east panels have produced more the west or south. there’s a few trees partially covering the south face, so output from that array is lower.

[sonofsven]

Just another data point, but my solar panels were installed in 2013 on a regular asphalt shingle roof and we've also had zero problems with leaking.

Congrats, your roof hasn't leaked yet.   

Ask any builder or roofer and they will tell you that 90% of roof leaks occur at gutters, valleys or "penetrations" thru the membrane.    Penetrations can include; chimneys, vents, skylites, antennas, furnace stacks, etc.   Solar panel systems require a bunch of mounting brackets that require fasteners (penetrations) at each.   Any intelligent roofer or builder will also recommend that you eliminate as much roof mounted stuff and / or penetrations thru the membrane as possible, to assure long and trouble free life out of your roof system.   Every penetration is a potential leak point and every time you set foot on your roof to do anything is an opportunity for damage creating a leak.

I built, repaired and maintained buildings of all types for 40 years and dealt with one heck of a bunch of roof problems.   Just providing some sound advice based on experience, take it or leave it.

you chime in on every single solar thread with the same exact statements and everyone with solar here is not reporting these issues think seem to be so common

I agree.  Unless you've actually encountered problems with rooftop solar, don't assume.  The penetrations Fishindude is talking about are obstacles where the sealed edge is above the shingle, in the path of water.  When mounting panels, the attachments are fastened under the shingles, so not much different than complaining about all the other thousands of roof penetrations that are made in a shingle roof.  A friend of mine owns a solar installation company and his hundreds of customers haven't complained about roof leaks.

I've also chimed in with my own lifetime of experience as a builder on these threads.
The last spec house  I built we put on a roof top grid tie system.
My roofer is the best roofer in the area, very old school. He hand nails the roof because it's better than using nail guns.
He came and looked at the install flashing method of the roof top system and helped install it. He gave it the thumbs up.
I trust his judgement, he's been roofing exclusively in an extremely wet and windy environment for more than 35 years.

Now, when it is time to replace the 50 year asphalt shingles it will definitely be an added cost to remove the panels first.

[BlueHouse]

I have panels installed with no incline on a flat roof.  They do okay in the winter.  They do well in the summer.
Due to my city's solar incentives, the panels/installation were free to me.  The benefit I get is my electric bill went from averaging $1300/year to $450/year.    And because they're laid flat, we were able to fit more panels on (and workers can walk on them apparently if they need to). 

As for the penetrations into the roof:  One of the options I had was to just place tilted panels on a roof rack held down with cinder blocks.  I was more uncomfortable with the extra weight of cinder blocks on a flat roof than with penetration.  The sealant the installers used was some fancy stuff that they really talked about a lot (I have no idea).  I had had a few leaks before going solar, so before any of the racks were installed, I had all the seals re-caulked and the entire roof sealed up.  I hope that with the roof now protected from the sun by the panels, I won't have to maintain the seals/caulking as much as I otherwise would have.