In-roof or on-roof panels - recommendation for suppliers / intallers South West

[Alan Ambrose]

Wow, looks v neat.

[Nickfromwales]

  On 11/02/2025 at 11:00, Alan Ambrose said:

Ah, picture paints 10,000 words. Thanks.

 

Is it a PITA to get your battens spaced so they suit both the tiles and the trays? I've looked at the GSE docs and they make it look v hard.

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Nope. A doddle, as we just programmed the roofer and let him crack on lol.

 

Very simple to do tbh, just time and labour / materials, nothing overly technical or complicated to it.

[Nickfromwales]

  On 11/02/2025 at 11:55, Nick Laslett said:

@G and J, besides the roof access requirements, it is easy to lift up a PV panel to access the solar diverter. The panels are held on with a few clips screwed into the tray. 

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+1.

[Nick Laslett]

  On 11/02/2025 at 12:52, Alan Ambrose said:

Wow, looks v neat.

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Thank you. I can’t take much credit the lads that did the roofing were excellent. It is worth remembering if you have gable ladders your roof might be as much as 30cm larger on either side. 
 

I just popped outside and took another photo. The fascias need a bit of a clean. I will get the gutters up one day. The ICF wall still needs cladding. 
 

 

 

[Dillsue]

  On 11/02/2025 at 10:27, Alan Ambrose said:

>>> or mounted behind/under the panels.

 

@Dillsue - so you can fit optimisers with in-roof trays OK? Or were you talking about on-roof at that point?

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I was talking about on roof but applies equally to in roof as others have show 

[marshian]

  On 11/02/2025 at 13:05, Nick Laslett said:

I just popped outside and took another photo. The fascias need a bit of a clean. I will get the gutters up one day. The ICF wall still needs cladding.

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That looks excellent - thanks for sharing an updated picture

[SteamyTea]

  On 11/02/2025 at 10:43, Nickfromwales said:

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That looks like a roof that is not going to be affected by shading, though I cannot see it all.

Is there a real reason to fit optimisers on it, rather than just allow the built in bypass diodes to do the work of disconnecting shaded parts.

[Nickfromwales]

  On 12/02/2025 at 12:31, SteamyTea said:

That looks like a roof that is not going to be affected by shading, though I cannot see it all.

Is there a real reason to fit optimisers on it, rather than just allow the built in bypass diodes to do the work of disconnecting shaded parts.

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Yea, the roof was H shaped and the hip out to the left had PV on the other side (west facing), the panels you see are south facing, and then the same out of shot (to the right of the image) for east.  Just small enough to put on a single string so inverters allowed us to have the 3 way split array. 👍

[G and J]

  On 12/02/2025 at 12:31, SteamyTea said:

That looks like a roof that is not going to be affected by shading, though I cannot see it all.

Is there a real reason to fit optimisers on it, rather than just allow the built in bypass diodes to do the work of disconnecting shaded parts.

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I’m thinking of optimisers to extend working beyond single panel failure, not to mitigate the effect of shading.  
 

But if the panels are that reliable and that easy to pop off and replace, and given that the optimisers are a significant proportion of the cost of a panel, maybe I should consider omitting the optimisers (at this stage) and accepting the potential future cost of professional panel replacement (I’m not as young as I used to be, even though I still happily dangle from ropes when I get the chance).

 

[Dillsue]

  On 12/02/2025 at 21:04, G and J said:

I’m thinking of optimisers to extend working beyond single panel failure, not to mitigate the effect of shading.  
 

But if the panels are that reliable and that easy to pop off and replace, and given that the optimisers are a significant proportion of the cost of a panel, maybe I should consider omitting the optimisers (at this stage) and accepting the potential future cost of professional panel replacement (I’m not as young as I used to be, even though I still happily dangle from ropes when I get the chance).

 

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I think panels are very reliable but if you do get a faulty one how do you know which one is faulty without monitored optimisers?

 

Remember that panel shading can be bird s**t, algae growth, passing clouds, neighbours trees growing, future telephone pole etc etc. Optimisers allow easy expansion using panels of differing wattage. They also allow panels on the same string to face differing directions without reducing collective production. If you're using SolarEdge optimisers, batches come up on ebay at a fraction of retail price so don't have to be painfully expensive

[G and J]

  On 12/02/2025 at 21:32, Dillsue said:

I think panels are very reliable but if you do get a faulty one how do you know which one is faulty without monitored optimisers?

 

Remember that panel shading can be bird s**t, algae growth, passing clouds, neighbours trees growing, future telephone pole etc etc. Optimisers allow easy expansion using panels of differing wattage. They also allow panels on the same string to face differing directions without reducing collective production. If you're using SolarEdge optimisers, batches come up on ebay at a fraction of retail price so don't have to be painfully expensive

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Good point.  I guess my naive thinking subconsciously assumed access to the jump cables so that checking voltages should be relatively easy.   Optimisers it is then.  Do any of them allow remote interrogation to easily determine which element is faulty?

[G and J]

  On 12/02/2025 at 21:32, Dillsue said:

panel shading can be bird s**t

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So I need a really, really, really powerful water pistol then….

[SteamyTea]

If you point an IR thermometer at panels, then the one with the highest temperature will be the failed one.

[Nick Laslett]

  On 12/02/2025 at 21:32, Dillsue said:

I think panels are very reliable but if you do get a faulty one how do you know which one is faulty without monitored optimisers?

 

Remember that panel shading can be bird s**t, algae growth, passing clouds, neighbours trees growing, future telephone pole etc etc. Optimisers allow easy expansion using panels of differing wattage. They also allow panels on the same string to face differing directions without reducing collective production. If you're using SolarEdge optimisers, batches come up on ebay at a fraction of retail price so don't have to be painfully expensive

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@G and J, here is a good YouTube video on the effects of shading on solar production. 
 

 

If you are not installing a battery, you might also want to look at micro inverters, they are more expensive than an optimiser and large inverter system, but they do have some advantages. Gary Does Solar has a good video going into the pros and cons of micro inverters. 
 

 

[Dillsue]

  On 12/02/2025 at 22:29, G and J said:

Good point.  I guess my naive thinking subconsciously assumed access to the jump cables so that checking voltages should be relatively easy.   Optimisers it is then.  Do any of them allow remote interrogation to easily determine which element is faulty?

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I don't know about Tigo or any others but SolarEdge has full monitoring of each optimiser/panel so you can see individual panel production. I think you can set alerts on their monitoring platform to let you know if any stop producing