Andrew Posted September 8, 2019 Share Posted September 8, 2019 We're just about to start soliciting quotes for the roofing on our build. We are going to have solar PV on the roof of the house and the detached garage and really like the look of the in-roof systems like GSE. However there are a couple of things we're not sure on :- 1) Who is the lead trade for the installation of the GSE system. I presume the mounting system and flashing is installed by the roofers but who would normally place the panels in. Obviously an electrician is also required at this stage to wire things up? 2) With the in-roof system we'd need to install the panels earlier in the build to get the roof watertight. At this stage the grid electrical connection may not be in place and the 1st fix electrics certainly won't be done. Is this an issue - the panels will presumably generating whilst on the roof and the sun is shining - would they need to be covered up? Would be interested in anyone's experience in these areas. Many thanks, Andrew Link to comment Share on other sites More sharing options...
ProDave Posted September 8, 2019 Share Posted September 8, 2019 There is nothing to stop the panels being fitted in advance of everything else. The one thing you need to decide is where will the inverter(s) go. then run the DC cabling from the panels back to that point and terminate the cables in the input terminals of the DC isolator switch(es). Then everything is safe and ready to connect later. 1 Link to comment Share on other sites More sharing options...
Alexphd1 Posted September 8, 2019 Share Posted September 8, 2019 (edited) There is not a clear sequence for this job, I installed the GSE kit and PV panels first (inc cables into roof space), slated second and then wired a few months later. It was a real PITA slating above the PV panels if doing again I would try to slate after installing the GSE kit but before installing the PV panels as @JSHarris did this would also protect the pv panels from being damaged from the slates, I was advised against this by the guy supplying and signing it of as he said it wouldn't work but I think it would. No problem with having a PV panel installed and not wired up unlike a solar thermal panel which could damage it. We also looped the connection between each pv panel into the loft space, this will make fault finding easier down the line. Edited September 8, 2019 by Alexphd1 1 1 Link to comment Share on other sites More sharing options...
dpmiller Posted September 8, 2019 Share Posted September 8, 2019 I'll second the difficulty of working above the panels. Our roof was an absolute mare as we've panels crammed in around a dormer and with a valley each side. But yes, you can fling them up, poke the wires through a nearby felt overlap, and carry on... 1 Link to comment Share on other sites More sharing options...
ToughButterCup Posted September 9, 2019 Share Posted September 9, 2019 If I could offer a hopefully helpful word or two. The term 'lead' doesn't matter. You'll need them to work together - well. Start with either trade, doesn't matter - if they're at all experienced, they'll know who to work with. But do check them both out thoroughly. Good excuse to go down and have a drink in their pub, and listen. You can safely leave unconnected panels on the roof. Good luck! Piccies, please! Ian 1 Link to comment Share on other sites More sharing options...
Andrew Posted September 9, 2019 Author Share Posted September 9, 2019 Thanks for the replies. I realised I've missed out a fairly crucial piece of info, sorry. We plan to use micro-inverters which I presume will be installed in the roof (in the big gap in the centre of the GSE mount), so it's the isolation of the AC output that was concerning me. 11 minutes ago, AnonymousBosch said: The term 'lead' doesn't matter. You'll need them to work together - well. Start with either trade, doesn't matter - if they're at all experienced, they'll know who to work with. But do check them both out thoroughly. Good excuse to go down and have a drink in their pub, and listen. Good point. I think it's probably the fear of looking stupid asking trades to do something that's not their bag (which I know I need to get over). Also I've found most of the people we've worked with so far to be really willing to help, even if it isn't their bag, but the results not always brilliant. It's so helpful to be able to sense check assumptions on here. Link to comment Share on other sites More sharing options...
SteamyTea Posted September 9, 2019 Share Posted September 9, 2019 13 minutes ago, Andrew said: We plan to use micro-inverters Does your roof have a shading issue? Link to comment Share on other sites More sharing options...
Jeremy Harris Posted September 9, 2019 Share Posted September 9, 2019 The sequence we used for installing our in-roof PV, using the GSE mounts, was to have the mounts fitted first, with all the wiring put in place for each panel. We then had the roofers in to fit the slates, and once the roofers had finished we had the PV people back in to install the panels on to the mounts and wire them up. I'm glad we opted to do it this way, as I wouldn't like to have roofers mucking about up there with the panels in place. Link to comment Share on other sites More sharing options...
the_r_sole Posted September 9, 2019 Share Posted September 9, 2019 (edited) . Edited September 26, 2019 by the_r_sole Link to comment Share on other sites More sharing options...
Jeremy Harris Posted September 9, 2019 Share Posted September 9, 2019 3 hours ago, the_r_sole said: what is the lifespan of these in roof panels? I always worry about making a roof structure to accommodate these when a roof covering is likely to outlast the panels on it... Probably unknown beyond about 25 years. There's no real change to the roof structure needed to fit in-roof PV, though. Our roof was just battened at the pitch needed for the slates: and then the GSE frames were fitted to the battens (with a few extra battens added where needed): The roof was then slated and when that was completed the PV panels were installed. 2 Link to comment Share on other sites More sharing options...
the_r_sole Posted September 9, 2019 Share Posted September 9, 2019 (edited) . Edited September 26, 2019 by the_r_sole Link to comment Share on other sites More sharing options...
Alexphd1 Posted September 9, 2019 Share Posted September 9, 2019 (edited) I am not 100% clued up on the wiring of micro inverters is the AC just linked together in series? How do you test individual panels without taking all panels of the roof to test? With a on roof set up you can get access to test connections without removing the panel. Edited September 9, 2019 by Alexphd1 Link to comment Share on other sites More sharing options...
SteamyTea Posted September 9, 2019 Share Posted September 9, 2019 (edited) 7 minutes ago, Alexphd1 said: I am not 100% clued up on the wiring of micro inverters is the AC just linked together in series? In parallel, be rather high voltage otherwise. 7 minutes ago, Alexphd1 said: How do you test individual panels without taking all panels of the roof to test? Not sure I understand the question. Test for what? Edited September 9, 2019 by SteamyTea Link to comment Share on other sites More sharing options...
Alexphd1 Posted September 9, 2019 Share Posted September 9, 2019 Brain fart there with parallel and series. Point I am trying to make, I have seen a few mc4 connectors fail over a short term, even tripping the system when it rains or 15 years down the line and a panel fails. In roof kit makes this a tough job to fault find, i dont know if all the connections with micro inverters are below the panel with the micro inverters or can I access them from inside? Link to comment Share on other sites More sharing options...
Jeremy Harris Posted September 9, 2019 Share Posted September 9, 2019 The only known problems with MC4 type connectors are that there were once some dodgy ones floating around, that originated in the Far East (pretty sure these are now easy enough to avoid - just buy from reputable suppliers) and there were some dodgy crimps made by incompetent installers using cheap and nasty crimp tools. A decent MC4, fitted to the proper size cable with a decent ratchet crimp tool, that is properly set for that type of connector, will be a very reliable connection, that should last for decades if it isn't subject to mechanical damage. Microinverters are a good solution for a system where panels are subject to variable levels of shade, but I'm not at all convinced there is any merit in fitting them to a system that doesn't suffer from patchy shading. Having an inverter that is easy to access, keep cool, or replace if it fails, is a big advantage. The single biggest cause of inverter failure, bar none, is heat, so fitting an inverter in as cool a location as possible will significantly extend its lifetime. Link to comment Share on other sites More sharing options...
Gone West Posted September 9, 2019 Share Posted September 9, 2019 3 hours ago, JSHarris said: The single biggest cause of inverter failure, bar none, is heat, so fitting an inverter in as cool a location as possible will significantly extend its lifetime. Although it looks like some micro-inverters have warranties twice that of standard inverters. Link to comment Share on other sites More sharing options...
Gone West Posted September 9, 2019 Share Posted September 9, 2019 3 hours ago, JSHarris said: Having an inverter that is easy to access, keep cool, or replace if it fails, is a big advantage. It's not something that I would want inside my house nor mounted on the outside of the house. Link to comment Share on other sites More sharing options...
Jeremy Harris Posted September 9, 2019 Share Posted September 9, 2019 5 minutes ago, PeterStarck said: Although it looks like some micro-inverters have warranties twice that of standard inverters. They do, but if they are fitted under roof-mounted panels, then that's a scaffold hire job to replace one if it fails, so quite costly. I could change our inverter in under an hour, with no need for any access equipment, just a matter of unplugging the connectors and lifting it off the mounting bracket that it hooks on to. Link to comment Share on other sites More sharing options...
Alexphd1 Posted September 9, 2019 Share Posted September 9, 2019 its all very nice having a long warranty on a micro inverter but are they going to pay for the scaffold to go up to remove the panels on the in roof kit to get access to the dam thing? Link to comment Share on other sites More sharing options...
Alexphd1 Posted September 9, 2019 Share Posted September 9, 2019 if a micro inverter fails is it easy to find which one? Link to comment Share on other sites More sharing options...
Gone West Posted September 9, 2019 Share Posted September 9, 2019 1 minute ago, Alexphd1 said: its all very nice having a long warranty on a micro inverter but are they going to pay for the scaffold to go up to remove the panels on the in roof kit to get access to the dam thing? Fortunately my panels would be on a single storey roof. I intend to install them from my scaffold tower. If you use their system, IIRC the Enphase software will tell you about faults. 1 Link to comment Share on other sites More sharing options...
Alexphd1 Posted September 9, 2019 Share Posted September 9, 2019 (edited) @Andrew if you are having any velux windows installed as well there is another PV inroof kit called easyroof which is compatible with the mk06 and mko8 size window. Its a very tidy solution. Edited September 9, 2019 by Alexphd1 1 Link to comment Share on other sites More sharing options...
Andrew Posted September 9, 2019 Author Share Posted September 9, 2019 (edited) 12 hours ago, SteamyTea said: Does your roof have a shading issue? Not especially, there is a neighbour's tree which will cause some minor shading at times. Main preference for micro-inverters was due to our panels being split over different sections of the main house roof and the detached garage. There seems to be an interesting debate regarding the benefits of micro-inverters vs normal inverter, the maintenance argument being quite persuasive. Is there any practical limit on how far the DC from the panels can be run? I guess we could have two 'normal' inverters, one in the house and the other in the garage. I'd need to have a look at how the cost stacks up too. Edited September 9, 2019 by Andrew Link to comment Share on other sites More sharing options...
Andrew Posted September 9, 2019 Author Share Posted September 9, 2019 3 hours ago, Alexphd1 said: @Andrew if you are having any velux windows installed as well there is another PV inroof kit called easyroof which is compatible with the mk06 and mko8 size window. Its a very tidy solution. Yes, we are having velux - I'll take a look, thanks. Link to comment Share on other sites More sharing options...
Bitpipe Posted September 9, 2019 Share Posted September 9, 2019 3 hours ago, Alexphd1 said: its all very nice having a long warranty on a micro inverter but are they going to pay for the scaffold to go up to remove the panels on the in roof kit to get access to the dam thing? Could you not do it with a cherry picker? Link to comment Share on other sites More sharing options...
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