For my new build I'd like to fit the solar PV and evac tube solar thermal units into the roof (replacing slates) rather than on to the roof. The house is in an Area of Outstanding Natural Beauty, so the planners are likely to be more receptive to such an approach (I hope........).

I've already looked at the option of using solar tiles, but they have some snags. The first is cost, they seem to be significantly more expensive than the best conventional panels (in terms of price per kWp) and they aren't very efficient, either (around 14% vs around 18% for Sanyo HIT panels). My available roof area is modest, so the higher efficiency (in terms of power per unit area) of the better panels is worth having. The other potential snag with the tile systems is that of getting any future replacements, should they be needed.

I'm coming around to the idea that one of the in-roof mounting systems might be the best bet, but there seems to be a bit of a dearth of information around about them (probably because most people fit solar to an existing roof). If anyone here has any practical knowledge of the pros and cons of some of the available in-roof mounting systems I'd be grateful.

The AONB in question (Cranborne Chase) normally objects to fitting panels, according to the information I've seen, hence the concern. There is a mention of it in the guidance on the Navitron site: <i>"If you live in a Conservation Area or in the Cranborne Chase or Dorset Downs Areas of Outstanding Natural Beauty, you will need planning permission for any solar panels that are to be installed on a wall or roof slope that faces a road or public footpath."</i>

Unfortunately, my roof faces the lane, so I do need planning permission and can't use PD as a way around it. I'm stressing that the panels are needed in order to get to zero carbon, in the hope that may sway things a little, but am aware that in the past the planners have used the fact that there is no need to exceed CSH level 3 at the moment as a means of turning down applications that include solar installations they don't like.

<blockquote><cite>Posted By: fostertom</cite>Don't suppose your roof cd be shown and approved as a 'conservatory' of patent glazing - then perhaps you could mount whatever you like e.g. PV or wet panels beneath that skin, and an insulated lining. Would Planning have any control over what you put behind a glass skin?</blockquote>

Nice idea, but I doubt the planners would wear a conservatory either, unfortunately, as they've already objected twice to the idea of rooflights (there have been five planning applications on this site so far........). I'm also facing a bit of an uphill struggle with appearance, as the planners are currently saying they want walls made from locally quarried stone, with brick detailing, and clay tiles. I'm dead set against digging even bigger holes in the ground just to build a house, so want to use oak cladding, which should be OK as the immediately surrounding houses are partially, or even completely, timber clad. Similarly, the is a mix of slate, asbestos slate, clay tile and even concrete tile on neighbouring properties, so I'm hopeful I can persuade them that slate is OK. The reason for wanting slate is more to do with helping to conceal the solar panels than anything else. My thinking is that the panels would be less obtrusive if set into a dark coloured roof.

Thanks for that, that's good food for thought. I have a steeper pitch to the roof than you (about 35 deg) so a system like yours should work OK for me, perhaps using lead flashing to blend in well with the slates. I like the idea of using standard mounting bits, too, as it means no expensive special parts.

The area I have earmarked for panels is a rectangle set smack in the centre of the roof, with roof lights either side. Having sketched up a few layouts it seems to look less obtrusive to have all the panels in one block rather than distributed around the roof as three separate blocks. It won't be a massive array, as the most I can get up there is around 2.5 kWp to 3 kWp, but that should be enough to offset most of the power the house needs through the year (I hope).

jeremy, following your lead I am now looking at conventional panels mounted on an in-roof rail system. I have the details of a couple of systems, which I suspect you probably have already researched as I think they may have already been mentioned on the forum, but if not can pass on details. The other point I was going to make was I know you were thinking of using the nu-lok system with ceramic tiles. I have recently received a sample of the ceramic tile and I would be concerned that your planners would reject them in an AONB. I wasn't convinced by the edge detail and I will probably be using their natural slate. Just a thought

<blockquote><cite>Posted By: Cav8andrew</cite>jeremy, following your lead I am now looking at conventional panels mounted on an in-roof rail system. I have the details of a couple of systems, which I suspect you probably have already researched as I think they may have already been mentioned on the forum, but if not can pass on details. The other point I was going to make was I know you were thinking of using the nu-lok system with ceramic tiles. I have recently received a sample of the ceramic tile and I would be concerned that your planners would reject them in an AONB. I wasn't convinced by the edge detail and I will probably be using their natural slate. Just a thought</blockquote>

Thanks for that. I'm wondering now if the Nu-Lok tiles are actually the same as Nu-Sustainable ones, as when I saw those I was quite impressed with the edge detail and general colour.

Hopefully the planners won't be too fussy, as those buildings nearby that have slate roofs seem to have the cheap and nasty asbestos slate stuff; I can only see one building nearby that seems to have real slates on it. The odd thing is that the planners insisted on clay tiles originally, yet they are really quite rare on surrounding buildings, most have either nasty concrete tiles or slates.

Posted By: JSHarrisThanks for that. I'm wondering now if the Nu-Lok tiles are actually the same as Nu-Sustainable ones, as when I saw those I was quite impressed with the edge detail and general colour.

yes it is the UK distributor.

Cav8andrew,
That's curious that the sample you have has a straight edge, as the ones I saw at Swindon looked fairly realistic at the edges, except for the fact that they were all identical (which you only noticed when up really close to them). I'm wondering if Nu-Lok do different types and styles, or perhaps the display roof was using a non-current design.

Borpin,
Thanks for the confirmation that Nu-Sustainable are the same people.

windy lamb,
Planners, don't you just love them? I'm aiming to use materials that look similar to the older houses that are nearest to the plot, those built between around 1600 and 1850, rather than the 1980's houses set up on the hill behind, as they are the ones most visible. Immediately opposite the plot is an old water mill with a cluster of surrounding buildings, all of which are timber clad with slate (or asbestos slate) roofing. The other nearby house is across the other side of a lane and is a mix of timber clad and stone construction, with clay tiles on the timber bits and slate on the stone bits.

<blockquote><cite>Posted By: CallumWalkerEnergySo</cite>The panels can be integrated into the roof.

One note of caution though, I'm not sure if this has been brought up. As the panel is not mounted on the tiles it will not be properly ventilated. Having the panel flush with your roofing can cause the panel to overheat thus reducing it's performance. In the end it may end up damaging the cell.</blockquote>

There's already been a fair debate about the ventilation difference and the possible impact on performance. Of course, an in-roof system IS ventilated anyway, because ventilation is required under the roof covering and above the permeable membrane, so the question we debated was whether the change in ventilation was significant. It may well be that the added chimney effect of the under-tile ventilation that has to be there is more effective than the limited airflow under an on-roof system as well, again as we've already discussed.

It's complete cobblers, I'm afraid, to talk about "damaging the cell" by in-roof mounting, certainly in the UK. Remember that PV panels are very prevalent in places with virtually no wind, daytime temperatures in the 40's to 50's and levels of insolation that are probably double those we get in the UK, yet they don't fail. Add in that they survive quite happily on spacecraft, where the only form of cooling is radiative and it's clear that heat is not a major issue and convective cooling is really just something that makes a terrestrial installation work a little better than one on a spacecraft in terms of panel temperature.

As I've already mentioned in the other thread where we discussed this, my experience with the panels on my boat is that the underside doesn't get very hot at all, by far the greatest proportion of panel cooling comes from the front face. Certainly PV efficiency drops by a few percent when the panels get very hot (I see about a 10 to 15% reduction on the electric boat when the panels are far too hot to touch). The fact is that even with a big space under the panels they will still get just as hot.