Which of these sites should I install on?

[hduz5]

Hi

I have been looking at installing a 3.96kwp solar pv system at my farm. There are three possible sites for the installation and I am trying to decide which site to choose. If anyone could offer any advice on which of the three options below would make most financial sense I would be extremely grateful. All sites are barn roofs and have more than enough physical space for the system with no shading issues.

Site 1.
Old stone barn, currently used for storage of hay.
Faces: 185 degrees south
Pitch: 45%
Material and condition: Thin corregated asbestos, mounted on very old, but structurely solid frame. Currently watertight, but may not remain so for another 25 years.
Good points: South facing.
Bad points: Has adjacent barn so scaffolding impossible, access only possible using cherry picker, which will add approx £800 to installation costs. Any problems with installation and cherry picker will have to be rented for additional days at additional cost.

Site 2.
Modern animal shed, approx 30 years old.
Faces: 275 degrees west
Pitch: 15%
Material and condition: Thick asbestos, wooden rafters, on steel frame. Unlikely to need maintenance in next 25 years.
Good points: Ease of access and working. Due to minimal tilt no scaffold required so £800 cheaper installation compared to site 1. Closer to consumer unit so wiring costs less too.
Bad points: Not south facing.

Site 3.
The opposite side of the roof to site 2. All specs the same except it faces 95 degrees east.

Any suggestions much appreciated. I am pretty new to all this.

 

[edexlab]

is it possible to have a ground mount array? this way you can have a south facing system = more productive
bad point might work out a bit more expensive ie cable run/ trench groundworks and the actual mounting frame itself

 

[Worcester]

I know there are lots of problems with asbestos, however so long as you can handle those, would it be possible to use crawler boards that spread the load over a number of purlins (you'll need to mount the frame direct on the purlins also) that may be your easiest way.

And effectively mount the array on a 'superstructure' on top of the existing roof anchored to the purlins, or is it a rafter type construction?

Same concept though, important thing is to assume that the sheeting isn't there structurally.

Asbestos is a H&S nightmare and you should go on a course so that nobody gets harmed.

Don't forget whatever you do you'll need planning permission and ground mount can be a nightmare. (and cost a bob or two)