Green Building Forum - Solar Options Mon, 26 Oct 2026 08:54:59 +0000 https://www.greenbuildingforum.co.uk/newforum/ Lussumo Vanilla 1.0.3 Solar Options https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18475&Focus=311363#Comment_311363 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18475&Focus=311363#Comment_311363 Sat, 05 Sep 2026 20:55:02 +0100 Victorianeco
Any grants available?
Preferred kit setup and size?
Export tariffs available?

I have little knowledge on the subject and we're a few weeks away from scaffold going up for the re-roof currently looking at cladco corrugated profiles and greencoat roofing systems but may be swayed by standard slate or tiles, but 100% confirmed either way.

But would like to start getting a few solar quotes together but looking at specs. to ensure I'll be comparing apples with apples in the quotes.

We have a cross gable roof with one elevation facing true south and the other roof section is half east and half west.

Let me know your thoughts on what the ideal setup is these days]]> Solar Options https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18475&Focus=311372#Comment_311372 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18475&Focus=311372#Comment_311372 Sun, 06 Sep 2026 21:30:35 +0100 philedge Solar Options https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18475&Focus=311543#Comment_311543 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18475&Focus=311543#Comment_311543 Tue, 22 Sep 2026 09:11:30 +0100 borpin
I've looked at the numbers several times and I just cannot justify the capital outlay. Folk say 'oh look at my low electric bill' but fail to take capital cost and depreciation into account (and don't bother throwing out the 'kitchen' analogy at me as I just don't buy it).

The only things that might sway the figures is high mileage EV and HP. I'm looking at a small EV for local use but even then, usually, I'd still be better off on Agile.

The Plugin Solar does interest me to cover my baseload during the day.]]> Solar Options https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18475&Focus=311544#Comment_311544 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18475&Focus=311544#Comment_311544 Tue, 22 Sep 2026 09:14:36 +0100 borpin Solar Options https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18475&Focus=311545#Comment_311545 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18475&Focus=311545#Comment_311545 Tue, 22 Sep 2026 09:29:06 +0100 Peter_in_Hungary Solar Options https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18475&Focus=311547#Comment_311547 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18475&Focus=311547#Comment_311547 Tue, 22 Sep 2026 09:31:54 +0100 fostertom Posted By: borpinThe money and markup they are making is utterly scandalousThat is depressing news. By now it should be a mature market with plenty of competition, making modest margins out of efficient operation. What factor is it that's making competition ineffective - or is there still under-supply?]]> Solar Options https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18475&Focus=311549#Comment_311549 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18475&Focus=311549#Comment_311549 Tue, 22 Sep 2026 10:24:10 +0100 borpin Posted By: Peter_in_HungaryIf the inverters are placed with the panels consider the problems of accessibility when replacing a failed inverter.Agreed. But, I have seen a lot about larger single inverters failing when out of their limited warranty (or the firm has gone bust) so the cost of replacing one Micro Inverter is way less than a larger inverter replacement (is my rationale).
Also no DC floating about!]]> Solar Options https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18475&Focus=311550#Comment_311550 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18475&Focus=311550#Comment_311550 Tue, 22 Sep 2026 11:05:10 +0100 Peter_in_Hungary Posted By: borpinso the cost of replacing one Micro Inverter is way less than a larger inverter replacement
Unless you have to put up scaffolding
and then when you get another failure the following year you have the scaffolding all over again.]]> Solar Options https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18475&Focus=311551#Comment_311551 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18475&Focus=311551#Comment_311551 Tue, 22 Sep 2026 12:50:05 +0100 djh Solar Options https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18475&Focus=311552#Comment_311552 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18475&Focus=311552#Comment_311552 Tue, 22 Sep 2026 13:11:45 +0100 philedge Solar Options https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18475&Focus=311553#Comment_311553 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18475&Focus=311553#Comment_311553 Tue, 22 Sep 2026 15:45:26 +0100 Peter_in_Hungary Solar Options https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18475&Focus=311557#Comment_311557 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18475&Focus=311557#Comment_311557 Wed, 23 Sep 2026 07:06:26 +0100 richardelliot
I would also definitely consider batteries. Being able to time shift your use, and force export during peak hours, is how I think you get the bigger savings.]]> Solar Options https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18475&Focus=311558#Comment_311558 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18475&Focus=311558#Comment_311558 Wed, 23 Sep 2026 10:47:32 +0100 WillInAberdeen
Have got these on a couple of outbuildings and they haven't been a huge success, inevitably a screw leaks a little and lets in water that softens the purlin wood and loosens the screw and then it leaks some more.

For a house roof I would go for a system which doesn't rely on screws with rubber washers to keep the rain out.



On scaffolding - any roof worker who is prepared to cut corners by working off a ladder in these days of scaffolding everywhere, is likely to be cutting other corners on the quality of the job.]]> Solar Options https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18475&Focus=311559#Comment_311559 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18475&Focus=311559#Comment_311559 Wed, 23 Sep 2026 11:14:14 +0100 borpin
Posted By: richardelliotI have micro inverters and one has failed. A replacement was sent out under warranty with no quibbles, but it isn't economic for me to replace it.
But, if it had been out of warranty, at least you have only lost a proportion of your generation. If it had been a single inverter, it would all be gone.

If under warranty, was the installer not liable to replace it?

Consideration of how you do work in the future at height should be a factor in your initial design.

I again go back to my point on whole lifetime cost. Solar has a finite lifespan and the replacement cost should be a factor in the 'I've got really cheap elec bills' statements.]]> Solar Options https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18475&Focus=311563#Comment_311563 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18475&Focus=311563#Comment_311563 Wed, 23 Sep 2026 11:56:44 +0100 fostertom Posted By: WillInAberdeen"corrugated profiles"

Have got these on a couple of outbuildings and they haven't been a huge success, inevitably a screw leaks a little and lets in water that softens the purlin wood and loosens the screw and then it leaks some more.That's alarming - have used 'corrugated iron' on a few domestic projects (inhabited space), no complaint so far.]]> Solar Options https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18475&Focus=311649#Comment_311649 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18475&Focus=311649#Comment_311649 Tue, 06 Oct 2026 22:05:59 +0100 jamesingram Exports around 12p kWh
5kW panels will be about £6k with Scaffold
Make you about £1k year
Don't use microinverters on simply arrays , they increase complexity and do go wrong
Don't feel you have to fit a battery
Return is about half what PV is
If your a hig energy user batteries make better sense]]> Solar Options https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18475&Focus=311653#Comment_311653 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18475&Focus=311653#Comment_311653 Wed, 07 Oct 2026 12:54:28 +0100 build4less
On the corrugated versus slate question, it's worth deciding the roof finish and the PV mounting together while the scaffold is up, as each affects the other.

If you go with metal, a standing seam sheet lets the panels clamp straight onto the seams with no holes through the roof at all, which sidesteps the leaking screw problem WillInAberdeen describes. With through fixed corrugated or trapezoidal sheets, both the sheet fixings and the PV brackets go through the roof, so the detailing matters. Fix through the crowns rather than the troughs where the water runs, use fixings with bonded EPDM washers, and tighten only until the washer seats rather than squashing it flat. Overtightened or angled screws are the usual cause of those slow leaks that then soften the purlins.

With slate or tile, an in roof mounting system replaces the covering under the array, so you buy fewer slates. Just make sure the flashing kit is made for your chosen covering, and agree up front whether the roofer or the PV installer is responsible for the flashings and battens around the array, so nothing falls between the two trades.]]> Solar Options https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18475&Focus=311655#Comment_311655 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18475&Focus=311655#Comment_311655 Wed, 07 Oct 2026 16:09:19 +0100 djh Posted By: build4lessa standing seam sheet lets the panels clamp straight onto the seams with no holes through the roof at allTo add: fixing the PV panels doesn't require holes either, the panel mounts clamp on to the standing seam.]]> Solar Options https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18475&Focus=311686#Comment_311686 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18475&Focus=311686#Comment_311686 Sat, 10 Oct 2026 11:20:46 +0100 build4less
Thanks djh, that's a fair addition and a clearer way to put it. With standing seam both the sheet itself and the PV rails go on without a single hole through the weathering layer, because the sheets are held by concealed clips and the panel mounts clamp onto the seams. That's a big part of why it suits a roof that will carry an array.

The one thing worth checking is that the clamps are matched to the actual seam profile and sheet gauge, as there are a few different seam shapes about and a clamp made for one won't necessarily grip another properly. It's also worth asking the sheet supplier whether fitting clamps affects their warranty, and confirming the seam spacing works with the panel layout before the sheets are ordered, so the rails land where you want them.]]> Solar Options https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18475&Focus=311691#Comment_311691 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18475&Focus=311691#Comment_311691 Sun, 11 Oct 2026 12:10:51 +0100 Victorianeco

How do I know if a battery would be worthwhile for my usage and payback?


Can you recommend in grid solar system?]]> Solar Options https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18475&Focus=311692#Comment_311692 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18475&Focus=311692#Comment_311692 Sun, 11 Oct 2026 13:14:11 +0100 build4less
I think the question was aimed at James, but on the battery side, the best way to judge it is from your own half hourly data. If you have a smart meter, your supplier's app or account page should let you download a year of usage. Look at how much you use in the evening and overnight against what the array would make during the day. A battery only pays by moving units you would otherwise export at around 12p into the evening, when you'd be buying at 25p or more, so the yearly saving is roughly usable capacity times the number of days it cycles times that price gap. A 5kWh battery cycling most days at a 15p gap comes out somewhere around £250 a year, so compare that with the installed price and a realistic 10 to 15 year life. A cheap overnight tariff improves the sums, because you can charge from the grid in winter too.

If you meant in roof systems, GSE and Viridian Clearline are the ones you'll come across most. Check the kit suits your covering and pitch, and that the installer is MCS certified so you can get the Smart Export Guarantee. Fitting it while the scaffold is up for the new roof is the cheapest time to do it.]]>