Integrated PV panels

[JackofAll]

Would like to go for integrated pv panels for 2 reasons, 1 think they look better and 2 less slate to go on the roof thus reducing the cost. Recently been told that integrated panels do not perform as well due to overheating as there's no air travelling at the back like those risen off roof on frame. How much better do those mounted on frames perform and anyone here go the integrated route?

[Conor]

There is airflow. Both under the trays / felt and under the panels as well (there's a good 25mm + void and a continuous gap at top and bottom on the trays). The centre of the trays are hallow and therefore part of your vented roof structure under the felt. Not as much as rail mounted panels of course. But I think the drop in performance is marginal and only really comes in to play over a certain threshold (I'm not sure what it is).

 

I went with GSE inroof trays in our natural slate roof and wouldn't do it any other way. The savings in slate and labour paid for half of the system. And it looks far better.

Edited October 9, 2022 by Conor

[JohnMo]

1 hour ago, JackofAll said:

been told that integrated panels do not perform as well due to overheating

Maybe true in very hot climate, but then only for a short period in the hieght of summer at midday for about an hour or so.

 

Really I would worry about it, 95+% of the time it's not an issue even in the summer.

[Radian]

1 hour ago, Conor said:

The centre of the trays are hallow and therefore part of your vented roof structure under the felt.

Mice will thank you for that.

[SteamyTea]

26 minutes ago, Radian said:

1 hour ago, Conor said:

The centre of the trays are hallow and therefore part of your vented roof structure under the felt.

Mice will thank you for that

I have wondered if it is necessary to punch a large hole in each tray.

Surely they must cause over ventilation if anything.

 

[JackofAll]

26 minutes ago, Radian said:

Mice will thank you for that.

Have heard of pigeons nesting under the frame mounted panels though not seen it.

 

41 minutes ago, JohnMo said:

Maybe true in very hot climate, but then only for a short period in the hieght of summer at midday for about an hour or so.

 

Really I would worry about it, 95+% of the time it's not an issue even in the summer.

Very true I guess.

 

1 hour ago, Conor said:

There is airflow. Both under the trays / felt and under the panels as well (there's a good 25mm + void and a continuous gap at top and bottom on the trays). The centre of the trays are hallow and therefore part of your vented roof structure under the felt. Not as much as rail mounted panels of course. But I think the drop in performance is marginal and only really comes in to play over a certain threshold (I'm not sure what it is).

 

I went with GSE inroof trays in our natural slate roof and wouldn't do it any other way. The savings in slate and labour paid for half of the system. And it looks far better.

Are the trays mounted direct to rafters or battens/counter battens?Great to hear the savings were as much as that.

[Conor]

2 hours ago, JackofAll said:

Have heard of pigeons nesting under the frame mounted panels though not seen it.

 

Very true I guess.

 

Are the trays mounted direct to rafters or battens/counter battens?Great to hear the savings were as much as that.

On the 25mm roofing battens. My roof though is a thermohouse panel system and is counter-battened, so I've a 25mm void under the felt as well as over.

 

The drainage ridges in the trays are about 10mm high or so and that keeps the panels off the plastic and provides the ventilation gap. Plus whatever airflow come from under/over the roofing felt - I've continuous soffit vents and dry ridge. Image below is an unusual section where the trays met a flat roof (flashed 300mm under) but again, the flat roof is counter-battened and vented.

Edited October 9, 2022 by Conor

[JackofAll]

24 minutes ago, Conor said:

On the 25mm roofing battens. My roof though is a thermohouse panel system and is counter-battened, so I've a 25mm void under the felt as well as over.

 

The drainage ridges in the trays are about 10mm high or so and that keeps the panels off the plastic and provides the ventilation gap. Plus whatever airflow come from under/over the roofing felt - I've continuous soffit vents and dry ridge. Image below is an unusual section where the trays met a flat roof (flashed 300mm under) but again, the flat roof is counter-battened and vented.

Picture paints... thanks for that Conor

[JohnMo]

No battens under mine, but the membrane has sarking boards below it.  Scottish roof design with slate is different from the rest of the UK, due wind loading being higher.

 

Still managed to get just over 3.1kW recorded at the hieght of summer from a 3.1kW system.

[JackofAll]

35 minutes ago, JohnMo said:

No battens under mine, but the membrane has sarking boards below it.  Scottish roof design with slate is different from the rest of the UK, due wind loading being higher.

 

Still managed to get just over 3.1kW recorded at the hieght of summer from a 3.1kW system.

Panels look tidy John also where both roof coverings meet.

[Thorfun]

5 hours ago, Conor said:

I went with GSE inroof trays in our natural slate roof and wouldn't do it any other way. The savings in slate and labour paid for half of the system. And it looks far better.

+1