In-Roof Systems - options and opinions

[AppleDown]

Just seen the latest Skill Builder video where they attach the panel directly to the battens and then add some fitted flashing:

 

Has anyone used that or know what system it is? Looks a complete pain if you need to switch out panels or access behind it though. My plan is still to use GSE trays, but happy to be swayed...

[SteamyTea]

Looks like a system that is designed to fail at every stage.

[JohnMo]

  On 05/05/2024 at 12:47, AppleDown said:

anyone used that or know what system it is?

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Viridian - there's a box on the video.

[Nick Laslett]

  On 05/05/2024 at 12:47, AppleDown said:

Just seen the latest Skill Builder video where they attach the panel directly to the battens and then add some fitted flashing:

 

Has anyone used that or know what system it is? Looks a complete pain if you need to switch out panels or access behind it though. My plan is still to use GSE trays, but happy to be swayed...

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I used the GSE in roof system for my install, very simple. When I looked at the Viridian system, there were specific panels it was specced for. I had already bought 2 panels for the first phase of my build, so these panels wouldn’t work with Viridian system. It is surprising how many different sizes there are of solar panels. 

 

 

[LiamJones]

@Nick Laslett I see you’ve ran the gse trays up to the eaves. What flashing/tray did you use to bridge this? Standard eaves trays are too small for the gap specified in the gse manual. 330mm. Considering using lead now. Or custom Ali trays 

[LiamJones]

For the OP. GSE trays with the Velux ODL kits for a seamless array. Not finished yet, trays/solar will go round all the velux.

[Nick Laslett]

  On 06/05/2024 at 06:48, LiamJones said:

@Nick Laslett I see you’ve ran the gse trays up to the eaves. What flashing/tray did you use to bridge this? Standard eaves trays are too small for the gap specified in the gse manual. 330mm. Considering using lead now. Or custom Ali trays 

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https://midsummerwholesale.co.uk/buy/roof-integrated-solar-pv/flexalu-330

 

I used the Midsummer solar panel web based design tool, which listed all the materials. https://easy-pv.co.uk
 

I didn’t see any specific issues from my reading of the installation booklet. 

[Guest28]

Personally I would never entertain the idea of putting PVs on the roof of my house and I would never buy a house that had PVs on the roof. In this country the risks far outweigh the benefits. The cost of one roof repair would wipe out the savings that the PVs bring. The cost of scaffolding and tradespeople etc. to do the repairs. There are lots of cases of PVs causing houses to burn down, birds nest under the panels and the panels get hot and ignite the nesting material etc. among other causes of fire. I would just give me anxiety thinking about all the things that could go wrong for the very limited generation of electricity.

 

One of the biggest problems in this country the poor standard of workmanship from tradesmen, you could get Bodgit and Scarper LTD to install your PVs then when you have problems with your PVs years down the line Bodge the Builder has put that company bust and is now operating under a different limited company and you have no comeback.

Edited May 31, 2024 by MBT6

[mike2016]

I was considering integrated panels on my new build to save on tiles, ascetics etc but due to no standard panel sizes am getting an on roof setup. Was hard to find any installers for integrated too. As its a new roof it should last well. Bird blockers to be installed too. 

[Kelvin]

The aesthetic is the draw here. Other than that it just seems all disadvantages to me. Panels can fail and need replacing. How easy is it to replace failed panels without compromising the roof especially years later.
 

I opted to not fit PV to our roof at all as we have the garden space to hide them on the ground. The thing that sealed the deal for me was a friend built a house, moved in, and a few months later a cable fault in a PV panel set the roof on fire. Took another year to rebuild it. 

[Thorfun]

  On 31/05/2024 at 11:07, Kelvin said:

The aesthetic is the draw here. Other than that it just seems all disadvantages to me. Panels can fail and need replacing. How easy is it to replace failed panels without compromising the roof especially years later.

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there's nothing un-aesthetic about the GSE panels in my opinion. people come to our place and say things like "i didn't know you had PV. i couldn't see the panels". it's not like everyone walks around looking up at the roof!

 

  On 31/05/2024 at 11:07, Kelvin said:

I opted to not fit PV to our roof at all as we have the garden space to hide them on the ground. The thing that sealed the deal for me was a friend built a house, moved in, and a few months later a cable fault in a PV panel set the roof on fire. Took another year to rebuild it.

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i can see how that would put you off but it has to be the exception. there are always stories of bad experiences of everything and if you let them affect you you'd never do anything!

[Pocster]

I think we have to keep some perspective here . A guy always moans to me that “ his friends” EV caught on fire due to a battery issue - therefore all ev’s are bad .

Personally I have panels on the roof not in it . My assumption is a panel is easier to replace with a different spec / size if need be . You can get bird wire to put round the edges to stop nesting birds etc . As always the quality of the installer is the weak point in the link . I deliberately choose an installer who literally lives 5 minutes away from me - so far I’ve not needed to visit them .

[Kelvin]

PV fires are clearly rare but not exceptional. There was a report in The Independent about them. There were 66 reported fires caused by roof PV systems in the first half of 2023 which was the same number as the whole of 2019. Likely a reflection on the number of new installations and ageing systems. Although it didn’t break the numbers down in that detail. 
 
Bit off topic so shall bow out. 

[Thorfun]

  On 31/05/2024 at 12:29, Kelvin said:

PV fires are clearly rare but not exceptional. There was a report in The Independent about them. There were 66 reported fires caused by roof PV systems in the first half of 2023 which was the same number as the whole of 2019. Likely a reflection on the number of new installations and ageing systems. Although it didn’t break the numbers down in that detail. 
 
Bit off topic so shall bow out. 

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i don't think it's off-topic and is good discussion 🙂 

[Pocster]

  On 31/05/2024 at 13:05, Thorfun said:

i don't think it's off-topic and is good discussion 🙂 

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I agree .

But it’s relative to number of installs . So you would expect “ pv related fires” to increase relatively. Imho I’d be more concerned about existing house wiring failing / pipe bursting or a Shelly melting ( I’ve read enough of the Shelly got hot and melted stories that I removed them - I had one ‘over heat ‘ and the lights weren’t even on …. 🥺 ) 

[Thorfun]

  On 31/05/2024 at 13:14, Pocster said:

I agree .

But it’s relative to number of installs . So you would expect “ pv related fires” to increase relatively. Imho I’d be more concerned about existing house wiring failing / pipe bursting or a Shelly melting ( I’ve read enough of the Shelly got hot and melted stories that I removed them - I had one ‘over heat ‘ and the lights weren’t even on …. 🥺 ) 

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absolutely. and also all relative to your risk appetite. tbh, if i had enough land and there was unobstructed sunlight to it i probably would've gone for ground mount but i want to use our remaining land for a garden and we have trees around us so with the panels being on the roof they should get a bit more sunlight.

[Pocster]

  On 31/05/2024 at 13:18, Thorfun said:

absolutely. and also all relative to your risk appetite. tbh, if i had enough land and there was unobstructed sunlight to it i probably would've gone for ground mount but i want to use our remaining land for a garden and we have trees around us so with the panels being on the roof they should get a bit more sunlight.

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If I had enough land I’d panel every inch of the ground . Install a wind turbine everywhere . Probably invest in a small nuclear reactor also .

[SteamyTea]

  On 31/05/2024 at 13:20, Pocster said:

small nuclear reactor

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A gram of tritium produces about 0.36W.

You can find tritium in most water, needs to be centrifuged out.

So to make a small 10 kW generator, you would need about 28 kg of tritium.

And lead lined panties, which you have already.

[Pocster]

  On 31/05/2024 at 17:29, SteamyTea said:

A gram of tritium produces about 0.36W.

You can find tritium in most water, needs to be centrifuged out.

So to make a small 10 kW generator, you would need about 28 kg of tritium.

And lead lined panties, which you have already.

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I’m on it ! Don’t remember any planning regs against nuclear reactors 

[LnP]

  On 31/05/2024 at 12:29, Kelvin said:

PV fires are clearly rare but not exceptional. There was a report in The Independent about them. There were 66 reported fires caused by roof PV systems in the first half of 2023 which was the same number as the whole of 2019. Likely a reflection on the number of new installations and ageing systems. Although it didn’t break the numbers down in that detail. 
 
Bit off topic so shall bow out. 

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Guidance on PV panel fire safety from the the Fire Protection Association here RC62 RECOMMENDATIONS FOR FIRE SAFETY WITH PV PANEL INSTALLATIONS

[Guest28]

In my opinion roof mounted PVs are a high risk - low reward option in the the UK. The lack of sunlight mean the rewards are quite low. You could also end up with the same thing that is happening in Germany, when so many people have PVs on the few days it is sunny there is too much electricity being produced and the grid can't handle it.

 

The poor standard of tradepeople mean the risks are very high. You could have Billy MacBodge come and install your PVs then it will cost a fortune in repair bills years down the line when MacBodge is operating under a different limited company so isn't liable for the repair.

 

Some family members of mine have ground mounted PVs and they have been quite good. Just wouldn't have them on my house because of the risks.

 

People add in PVs just to get their SAPs calculations across the line. I don't think roof mounted PVs should count towards a SAPs calculation, shouldn't be incentivising people to do something risky.

[JohnMo]

  On 03/06/2024 at 09:30, MBT6 said:

In my opinion roof mounted PVs are a high risk - low reward option in the the UK. The lack of sunlight mean the rewards are quite low. You could also end up with the same thing that is happening in Germany, when so many people have PVs on the few days it is sunny there is too much electricity being produced and the grid can't handle it.

 

The poor standard of tradepeople mean the risks are very high. You could have Billy MacBodge come and install your PVs then it will cost a fortune in repair bills years down the line when MacBodge is operating under a different limited company so isn't liable for the repair.

 

Some family members of mine have ground mounted PVs and they have been quite good. Just wouldn't have them on my house because of the risks.

 

People add in PVs just to get their SAPs calculations across the line. I don't think roof mounted PVs should count towards a SAPs calculation, shouldn't be incentivising people to do something risky.

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Not agreeing with much of the above.

 

Since September I've generated close too 2,500kWh, nothing much exported. I'm in NE Scotland, so plenty more solar would be generated further south. My summer bills will consist of mostly standing changes.

 

Electric suppliers cap what can be exported to what the local system can handle.

 

Using the correct crimping tool to make up connections is a must, other than that is all very straightforward.

[Mattg4321]

Using poor trades is going to be a problem in many situations. 
 

Solution, find some good ones. Plenty out there, although not always easy to find. Word of mouth is best. 

[JohnMo]

  On 03/06/2024 at 11:09, Mattg4321 said:

Using poor trades

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This is true for all work in all situations PV, cars, other stuff. 

 

Like all things you need to do the due diligence.

 

  On 03/06/2024 at 11:09, Mattg4321 said:

Word of mouth is best. 

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Couldn't agree more, speaking to other trades people is good, they know each other they have worked with them. That's how I found nearly all my trades when building, they come with people that don't advertise, because they are good and fully booked, but they lead to others, that are good. 

[Nick Thomas]

One of the upsides of an MCS install is that it must come with an insurance-backed guarantee. Which means that even if...

 

  On 03/06/2024 at 09:30, MBT6 said:

You could have Billy MacBodge come and install your PVs then it will cost a fortune in repair bills years down the line when MacBodge is operating under a different limited company so isn't liable for the repair

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...happens, then whoever was insuring them at the time still pays for the repairs. With the regular caveats about insurance companies being evil, obviously.

 

Even at MCS prices, the payback on my system is ~7 years, the rated lifespan 25 years, and it has a reasonable chance of lasting much longer than that.