Large scale advice - 7 Degree pitch

[finchy]

I'm pricing on a factory for 50kWp install with 7 degree slope but east west facing roof. I was wondering if it was feasible to install a flat roof system by positioning the arrays facing South? The plans only hit my desk this afternoon and want to hit the ground running so advice would be very much appreciated. Up to now we pretty much have done every combination up to 4kWp and one under 10kWp all on tiled roofs.

I'm going to look at the roof structure to check type, however can anyone point me to the Best flat roof system, we've used "on Roof" Schuco and Schletter and was going to look at what options they have to offer and speak to their reps.

Thanks

 

[JD6400]

If i have read your post correctly , i can not see how you will overcome the 7 degree pitch ?
There is a fair train of thought that thin film would be best on such a shallow pitch if you end up going east / west , but what ever you choose watch out that you do not invalidate the module warranty's by going below a 10 degree pitch as some will not take it .

 

[finchy]

Nothing and for 3 weeks and his comes in, why cant it be straight forward !! Thanks for the warranty point ! I was thinking of mounting them using a frame at 25degrees on the 7 degree slope to enable the modules to benefit from South rather than a East/west installation......

 

[JD6400]

Bare in mind that if you go out of the delineation ( i think this is the word i mean :49 of the building , you will open up yet more planning issues .
And i can not envisage how you would not ?

 

[troglodyteRob]

You could try Renusol Console. But check whether they are OK for 7 degree pitch. I've got some pictures and info about them on an ebay listing - search for "pv roof console". I don't think my 17 will get you far on a job that size, but the pics and info might help.

 

[jupestar]

we did exactly what you are suggesting on a lead roof, east west but tilted them up to about 20 deg south facing, just by putting in some angle brackets... wasn't cheap but does look great will post some photos....

 

[finchy]

Thanks Jupestar if you could or pm me, I was sure it was possible ! I went to the black forest last summer and saw all sorts of installation but sadly my wife and kids would have left me if I had stopped at every site to get information. The Black forest is recommended for Solar PV anoraks !

 

[Zach Halley]

I wouldn't foresee this posing a problem, from a mounting point of view, but your choice of mounting structure will depend on the roof covering. And whether or not you can penetrate it

 

[solarsparkie]

together with our metal fabricators they came up with a design for variable mountings summer winter pitches to increase yield , we only use the one type of panel but if you could post me the panels you use with dimensions length width and depth would be useful

 

[steve Leese]

We have done an instllation as you describe just recently,20kw on a west facing roof (10degrees ) with all108 panels facing south at 30 degrees, we have had our MCS inspection today and used this job, it was gone over with a fine tooth combe and passed with flying colours, its a bit complex convincing the planning office ( national parks ) but they came around in the end.

 

[powervan]

DELINEATION I LOVE PV JUST FOR ALL THE NEW WORDS I LEARN (not the money i dont earn)

 

[solarfred]

We ran into problems with a modern metal clad factory building as the roof support structure is built to narrow tolerances and is not designed to take any extra loading apart from a bit of snow. You may need to reinforce with support columns. What did the structural engineer report say?

 

[Worcester]

Crazy as it may seem sometimes just putting it 'flat' on the 7 degrees also works.

We have one 50kWp install done just as like that, 'flat' on a 5 degree roof, facing East. Actual results are quite staggering because it is so flat it generates almost the same amount all day long and in September last year was even generating at 8pm when the sun was well in the west, when a south facing 30 degree would have all but shut down .... (when you're sunbathing do you sometimes just lie down on the beach, or do you prop yourself up at 30 degrees south facing )

 

[finchy]

Cheers for the posts. I'm considering that after Schuco technical closed the door on advice of mounting frames options without any help as is curved not square roof ! The roof is concrete corrugated (awaiting asbestos results on steel purlin's ). Just need to ensure warranties of panels and find an adequate fixings.

 

[jupestar]

Hello Finchy,

I know I'm a bit slow but this is the system we put in, Wurth system the angle bracket are adjustable. Didn't get any finished photos as we dark when we finally finished it.

As someone else suggested you can even lay them down on the west roof at 7 degrees, you get more capacity on, and is cheaper both with install time /KWp and mounting.. so can work out better for client depending on cost etc. This one was a deaDline beater - no time for DNO - so client wanted as much KWh/KWp for his 10KW limit. So we angled it up.



Apparently there is a system which you can stick to the roof, not sure how this works, one of our clients has seen it and wants us to do it on their shopping centre. I've asked for specifics cause it all sounds a bit dodgy to me. anyone heard of this? - i'm having sleepless nights just thinking about it.

 

[finchy]

Cheers jupestar - to be honest I presented the 50kwp system to my customer which they liked but it only produced approx a quarter of their day time electrical consumption. They want a MUCH bigger system, so back to the drawing board. So my proposal is to mount the 50kWp on the north face, giving a negative 7 degrees pitch. And a 100kWp array on the south, but flat roof mounted. Ive left the ball in the customers court as i have completed a preliminary design as the next stag is to look into the feasibility interms of structure and DNO, however I want to negotiate a management/consulting fee.