Integrated PV's - slate roof

[Lotobear]

Loto junior has bought an old stone cottage that requires a complete refurbishment. It will be a great father and son project - I'm a chartered building surveyor so I know what is needed and how to achieve it.

The roof has spread (traditional triple roof structure) so we are going to re do it with gangnail trusses. The roof is Welsh slate and there should be sufficient good slates to recover one slope - the main elevation. We were going to do the rear slope in a Cupra Welsh look-a-like but have now been thinking it might be a good idea to incorporate a decent array of inset PV's - the rear roof is directly south facing to a private garden and can be seen so it won't spoil the look of what is a traditional cottage

I know very little about PV's or renewables generally and have struggled to find a supplier with good information on supply price and installation details. A few questions:

1) What sort of price per panel and any suggestions on 'friendly' suppliers
2) Are inset PV's likely to be cost neutral when compared to new slate per square metre?
3) If we install an array it's more to future proof and we would probably not install inverters/batteries at this stage or a grid connection (house has a fairly new gas fired combi boiler and woodburner) - can panels be fitted and not connected? Probably showing my ignorance here but surely they will immediately generate when exposed to a light source and does that generation need to be 'dumped' somehow.

Cheers

[AdamV12V]

Lotobear said:

Loto junior has bought an old stone cottage that requires a complete refurbishment. It will be a great father and son project - I'm a chartered building surveyor so I know what is needed and how to achieve it.

The roof has spread (traditional triple roof structure) so we are going to re do it with gangnail trusses. The roof is Welsh slate and there should be sufficient good slates to recover one slope - the main elevation. We were going to do the rear slope in a Cupra Welsh look-a-like but have now been thinking it might be a good idea to incorporate a decent array of inset PV's - the rear roof is directly south facing to a private garden and can be seen so it won't spoil the look of what is a traditional cottage

I know very little about PV's or renewables generally and have struggled to find a supplier with good information on supply price and installation details. A few questions:

1) What sort of price per panel and any suggestions on 'friendly' suppliers
2) Are inset PV's likely to be cost neutral when compared to new slate per square metre?
3) If we install an array it's more to future proof and we would probably not install inverters/batteries at this stage or a grid connection (house has a fairly new gas fired combi boiler and woodburner) - can panels be fitted and not connected? Probably showing my ignorance here but surely they will immediately generate when exposed to a light source and does that generation need to be 'dumped' somehow.

Cheers

We have installed an integrated solar shingle roof on our house renovation as it needed a full reroof.

1) Varies hugely depending on which of the various shingle / integrated-pv providers you choose. Two things however are almost certainly true of solar shingles a) they are going to be more expensive and less efficient than normal solar panels which are available at the same time of purchase. b) they look hugely better than solar panels when installed. For us, b) outweighed a), but for most people it will be the other way around as many see solar purely a money saving scheme and don't care too much about how their roof looks.

2) No, they will be a lot more expensive than just slates, however you can save on the cost of slates where you put solar shingles instead, so there is a bit of an offset in cost compared to reroofing with 100% slates, although many of the shingle systems require a specific method of installation which further adds to cost.

3) Firstly you'll very likely need planning permission, especially if your in a conservation area or similar. You can only install solar on a roof either by submitting a G98 (max 3.68kw) immediately after installing, or with prior approval of a G99 for > 3.68kw. Yes you could install them and not connect them to an inverter but given that inverters would typically cost less than the shingles it would seem a bit daft not to spent the rest and start to extract value from them. You will also likely want to run the cables and connect all the shingles up into strings to avoid having to recable later - however the string strategy will be tied into your choice of inverter and how many it can support. The solar cells will begin to slowly age once exposed to sunlight and of course weathering, risk of damage from trees etc..., so again it seems a little daft not to use them straight away unless that intial period is just a few months whilst you get around to installing the pre-chosen inverter and batteries.

You will also really want to choose your battery, inverter and size of solar array together, and will need some careful planning and sizing, so just throwing down a handful of solar shingles now without thinking it through properly could end up in regret.

From what I know now:

Would I do solar again - maybe, maybe not. I have mixed feelings, amazing in summer, but bordering on useless in winter when you need it most.
Would I install a battery again - absolutely yes, indeed I expect to increase our battery capacity before we finish the project.

Edited by AdamV12V on Thursday 10th July 15:18

[Lotobear]

AdamV12V said:

Lotobear said:

Loto junior has bought an old stone cottage that requires a complete refurbishment. It will be a great father and son project - I'm a chartered building surveyor so I know what is needed and how to achieve it.

The roof has spread (traditional triple roof structure) so we are going to re do it with gangnail trusses. The roof is Welsh slate and there should be sufficient good slates to recover one slope - the main elevation. We were going to do the rear slope in a Cupra Welsh look-a-like but have now been thinking it might be a good idea to incorporate a decent array of inset PV's - the rear roof is directly south facing to a private garden and can be seen so it won't spoil the look of what is a traditional cottage

I know very little about PV's or renewables generally and have struggled to find a supplier with good information on supply price and installation details. A few questions:

1) What sort of price per panel and any suggestions on 'friendly' suppliers
2) Are inset PV's likely to be cost neutral when compared to new slate per square metre?
3) If we install an array it's more to future proof and we would probably not install inverters/batteries at this stage or a grid connection (house has a fairly new gas fired combi boiler and woodburner) - can panels be fitted and not connected? Probably showing my ignorance here but surely they will immediately generate when exposed to a light source and does that generation need to be 'dumped' somehow.

Cheers

We have installed an integrated solar shingle roof on our house renovation as it needed a full reroof.

1) Varies hugely depending on which of the various shingle / integrated-pv providers you choose. Two things however are almost certainly true of solar shingles a) they are going to be more expensive and less efficient than normal solar panels which are available at the same time of purchase. b) they look hugely better than solar panels when installed. For us, b) outweighed a), but for most people it will be the other way around as many see solar purely a money saving scheme and don't care too much about how their roof looks.

2) No, they will be a lot more expensive than just slates, however you can save on the cost of slates where you put solar shingles instead, so there is a bit of an offset in cost compared to reroofing with 100% slates, although many of the shingle systems require a specific method of installation which further adds to cost.

3) Firstly you'll very likely need planning permission, especially if your in a conservation area or similar. You can only install solar on a roof either by submitting a G98 (max 3.68kw) immediately after installing, or with prior approval of a G99 for > 3.68kw. Yes you could install them and not connect them to an inverter but given that inverters would typically cost less than the shingles it would seem a bit daft not to spent the rest and start to extract value from them. You will also likely want to run the cables and connect all the shingles up into strings to avoid having to recable later - however the string strategy will be tied into your choice of inverter and how many it can support. The solar cells will begin to slowly age once exposed to sunlight and of course weathering, risk of damage from trees etc..., so again it seems a little daft not to use them straight away unless that intial period is just a few months whilst you get around to installing the pre-chosen inverter and batteries.

You will also really want to choose your battery, inverter and size of solar array together, and will need some careful planning and sizing, so just throwing down a handful of solar shingles now without thinking it through properly could end up in regret.

From what I know now:

Would I do solar again - maybe, maybe not. I have mixed feelings, amazing in summer, but bordering on useless in winter when you need it most.
Would I install a battery again - absolutely yes, indeed I expect to increase our battery capacity before we finish the project.

Edited by AdamV12V on Thursday 10th July 15:18

Thanks for this - just for clarity, it's inset panels we are considering not shingles/slates

[dmsims]

Look at GSE in roof

https://midsummerwholesale.co.uk/buy/roof-integrat...

City plumbing are good for panels (free delivery)

Longi 450W are £61.19 + VAT

Try Bimble Solar as well

Edited by dmsims on Thursday 10th July 15:42

Edited by dmsims on Thursday 10th July 15:44

[Aluminati]

With ‘in roof’ systems, with a tile, they appear fairly flush. With a slate, they still stand proud. How much of an issue is aesthetics ?

[OutInTheShed]

Aluminati said:

With in roof systems, with a tile, they appear fairly flush. With a slate, they still stand proud. How much of an issue is aesthetics ?

I think, if you are re-fixing the whole roof that can be avoided?

there is a refurb I walk past which has black solar panels inset into slates, it looks very good IMHO.
I guess over time, the slates will fade and the panels won't though.

[Aluminati]

OutInTheShed said:

Aluminati said:

With in roof systems, with a tile, they appear fairly flush. With a slate, they still stand proud. How much of an issue is aesthetics ?

I think, if you are re-fixing the whole roof that can be avoided?

there is a refurb I walk past which has black solar panels inset into slates, it looks very good IMHO.
I guess over time, the slates will fade and the panels won't though.

Only if you counterbatten.

[OutInTheShed]

Aluminati said:

Only if you counterbatten.

I knew there was a word for it!

The battening and leadwork didn't look trivial to be fair.

But I think the end result is much nicer than the typical solar panels slapped on as an afterthought, which even seems to afflict many new houses.

Around here, it's important not to create a nesting spot for the gulls.

[Aluminati]

OutInTheShed said:

I knew there was a word for it!

The battening and leadwork didn't look trivial to be fair.

But I think the end result is much nicer than the typical solar panels slapped on as an afterthought, which even seems to afflict many new houses.

Around here, it's important not to create a nesting spot for the gulls.

Very few systems if any are raised now, mainly for the reason you highlight. The main issue in solar currently is the installers. 99% of them are dire.

[Lotobear]

Aluminati said:

With in roof systems, with a tile, they appear fairly flush. With a slate, they still stand proud. How much of an issue is aesthetics ?

Aesthetics are important but not a key factor in this case given this would be on the rear elevation which is not visible (and which faces due south). We would not have them on the front roof even if we were paid lots of money to do it.

Full disclosure - I detest PV's on roofs most especially on traditional properties but as ever there is always an economic trade off and were it not for the fact it needs and entirely new roof we would not be giving them a second thought. I am driven by the thought that if inset PV's can also double up as the weather resistant covering then they might be worthy of consideration.

I PM'd this job around 11 year ago when the same question arose - client was fully engaged philosophically on the whole renewable gig (fully funded by Dad so an easy position to take) so we went for inset PV's as the roof needed to be reslated. They might look better now and at the time I seem to recall they were cost neutral against new Welsh slate at the time.

Clearly these are still above the main slate line but much better than 'sit on' panels. We could cope with that, given it's not on the principal elevation.