Probably not an issue in the UK, but in more southern climates with higher insolation, panels overheat - which causes their efficiency to drop significantly. Natural convection between the roof and raised panels has a significant cooling effect - which is missing completely in an in-roof installation. Not sure of actual numbers though.
You are right, heat soak is an issue with rooftop installations and efficiency drops with increasing temperature, even for installs here in Belgium which is not exactly a tropical location. If you have ever spend time on a solar roof around noon, you will attest it becomes unsufferably hot, you can see the hot air mirage where the air seems to be vibrating. On the other hand, these hot periods usually correspond with lower demand for power and lower feed in tarrifs drop because of the excess PV supply anyways. If your system is overdimensioned to accomodate for lower production in the winter it should cope... It will get hot in the barn for sure....
Solar panel outputs are rated when the panel temperature is at 25c, it is rare for panels to be that temp' when there is full sun, especially in summer. For every 1c rise in temp' the panels derate about 0.5% (it varies from brand to brand). It is not unheard of for panels to reach 70c in the middle of the day in summer, so you lose about 22% of you rated output. at that temp'. Having zero air gap under the panels will not do much to cool the panels. They may look good, but are a failure in the cooling stakes.
Not everyone has the uncapped budget of this particular customer . My 3.2kw solar array , 7kwh lifepo and 3.6kw inverter cost me £4k . My electric bills have dropped to almost zero whereas i paid ~£3k last year .
Viridian is brilliant system. I installed it myself when the roof was being replaced. Matches up perfectly with the Slaredge Optimisers / Inverters. Would recommed to everyone. Also to add, stops the bloody pidgeons nesting under frame based panels.Well done guys.
He said planning but later when he elaborated, that six months was for design, planning permission, removing the old roof and building the new roof, so not as bad as it sounded.
I've just been involved in helping to install a 1200 panel Solar Panel installation on a big factory rooftop area of the English Provender foods Company over on Greenham Business Park, in Newbury, Berkshire, (for the last 8.5 weeks until today), which included 598 Optimizers (SolarEdge), and four Solar Edge inverter units, and so I understood this video quite well, and found it to be especially interesting to me. I also worked on a new-build 29,000 panel Solar Farm (back in 2014) on the outskirts of my village in Oxfordshire (for 4.5 months), so I've learned quite a lot about this sort of stuff at first hand.
I've done 3 of these now, me and an apprentice. We went down the micro inverter route, but we smashed 10 panels and flashing in a day and we didn't start till half 9. Rate it alot!! Quick easy and no d.c in side
Enphase supply pre made a.c lead to link inverters and strings plug into individual inverters so you're left with a 2meter a.c lead in the loft. 6mm armoured from consumer unit upto rotary isolator in loft and next to board with meter 👍
Top tip: Always supply 1 spare panel with an in roof system. Why? Because if a panel goes faulty, while it might have a warranty, there might not be any obligation to supply an “identical” replacement panel. Most likely you’ll get a “similar” panel in terms of performance, but it could be different height and width, at which point it doesn’t fit the tight tolerances of an in roof system. On roof systems don’t have this problem. If your replacement panel is too big, in most instances it’ll fit in the corner of the array and just look ugly.
My in roof has got a contaminated panel and the installers warranty has proven to be useless, basically say I have to speak to the manufacturers in China who charge ridiculous amounts to supply and ship and installers charge labour to replace it. Useless warranties are no doubt par for the course so a spare panel is good advice.
@@aldozilli1293 Warranties are useless. I have two on-roof solar systems (my energy needs increased when I got an EV). The panels of the first were from a Canadian company that went bust shortly after. I learned my lesson on the second, and went with LG. Who then exited the PV business and my warranty is now also useless. Thankfully only 3 of 24 panels are underproducing, and I have microinverters so none of the others are affected. Given difficulty in finding visually matching panels and labor costs, it's pointless to replace individual panels.
@@aldozilli1293 good lesson to everyone. Chinese panels and the companies that stand behind them are dog shit. I own a business with > 65000 systems in place. We offer US made panels exclusively and we guarantee to stand behind their warranties with our own
Hopefully you can easily replace a panel when one goes faulty. What if they become obsolete and new panels are not compatible with roof space from previous panel?
Great video, apprecite the amount of depth you went into on the install process. I really wish we'd be at a point where it was mandatory for all new builds to be doing this, it's such a simple and beneficial thing to be doing to new houses.
I have an in-roof as we replaced the roof/fascia's at the same time. Saved us a lot of money in Tiles as 90% of the front of the house is Panels not tiles and looks so much neater. Thanks for another interesting video guy's.
I love how sleek the PV-install looks! However when thinking about maintenance and repair such an install could be a hassle.... How do you take a single damaged panel off the roof?
We had the same system fitted as a retro fit as needed to replace the underfelt, 18 x 335 panels in portrait on east side and 18 on west side all with optimisers in the loft space and connected to a 8kW SolarEdge inverter.
It should not fail completely but operate at reduced power where optimizer can correct for that. But it looks like it will be easy to bypass it with a jumper wire if necessary. If few panels do end up failing completely the system can still operate at reduced power until multiple panel replacement becomes financially beneficial.
Would counter battens be better for the ventilation of the panels and ventilation for the roof to remove condensation.. If air can get in it will dry out any small water leak imperfections/condensation if the customer applies insulation inside. A ventilated roof is always going to be a better job. .
I own a solar company in the us with more than 65000 home systems installed. I can say with absolute certainty that the roof pitch utilized here is in no way ideal. For year round ideal production on a system, 50* of tilt or a 14/12 roof pitch would work best The other issue with this system is that you are losing convective cooling, which is the same reason a tesla roof tile is wildly inferior vs a high qualify PV module
Really interesting, I do have a few points - 1) The risk with solar panels onto a roof is typically wind uplift, not weight increase. The in roof systems avoid this as they are not making a sail, so you're right that it might avoid needing a structural engineer, but not necessarily for the reasons you state here. 2) I can't say that I'm too impressed with the Viridian system between the upper rand lower panels and I don't see why they couldn't have made a flashing to sit over the frame of the panel below so that there isn't a channel between the upper and lower panels - moss and leaves will love that gap! 3) It would have been worth fitting panels to the North face as well. The need for panels to be due South is overrated and if anything they will get far hotter which will reduce the performance, so North facing panels would then pick up the slack. These could still be limited by the inverter if needed to keep the output below the 4.5Kwp cap on a single phase supply. Seems a missed opportunity.
I really agree with point 2, not too impressed with this system. Build up of moss and dirt. But also the waterthighness is a risk over the years. Is it watertight when 10cm's of melting snow lies on top of it or will it seep through? No offence by the way, because I think it's hard to design a in-roof system that will function flawlessley for 25 years.
There's no channel between upper and lower panels, they have a joining strip with an 5mm wide upstand which allows for water to drain off into the drainage channels running vertically and prevents any build up of leaves, moss etc
@@jayriddo3010 Take a look at 9:22, there's a channel formed after the joining strip is inserted between the panels. I appreciate that it's only the upstand thickness on the edge of the panel below, but say that's 10mm deep then you've got an awful lot of water accumulating and as soon as there's some bird mess in there it'll be well on the way to an eco-system by itself. It'll be fine when it's new as the water should shed to the sides by itself, but I can't see it ageing well once there's some dirt in the grooves.
I really disagree. I mean sure when you live somewhere hot like Arizona you want also a north facing roof. North facing roofs are however, beyond idiotic in most places. For reference, New York and Madrid are on the same level. Europe is much further up north than the US. North facing panels in the UK, with it's gulf stream mediocre weather, mild summers, mild winters, barely any northern sun hours, is the biggest waste of money one can make.
I think the lathing must be done vertically and next layer horizontally. Now, the condensate from the diffusion film will have nowhere to escape and you additionally drilled film when attaching the panels...
Yes. They did it wrong AND penetrated the water barrier with a zillion screws. Comically wrong. Guaranteed to leak and guaranteed those horizontal batten dams they installed will trap water and rot out that roof.
I can show you a roof where a part of the modules (total 24 kW) is set up on a flat roof with correct ventilation, a part is fixed a little too close to a roof below, so less ventilation, same inclination. Same modules, same production batch. After 18 years, 38% of the panels mounted on the less ventilated are had errors that cost them 33% of their respective yearly production (A substring fails means 1/3 in gone) By not having a proper ventilation behind the modules, you not only lose up to 30% efficiency when hot, you reduce lifespan considerably. Also I dispute that it may possible to mount the module so that absolutely no water gets behind: We have considerable heat expansion so the modules must have a gap to compensate for that. The gap is where the water will come in but not a problem if you set the modules on top of a roof, not integrate them as you did. I am all for optical integration but there needs to be ventilation.
how do you replace panels? do you have disassemble the string so you can get to the panel that needs replacing or can you cherry pick out of the string?
I quite like the idea of this - my poor installers had to repair/replace a shedload of slates on my on-roof install about 10 years ago - when the roof needs replacing this will be a no-brainer if I can get it past planning. The downside I can see is there is no air gap for cooling - likewise with the optimisers being under the roof - however replacing them would be far easier in the loft 👍 I’ve had the misfortune of replacing one recently although it was one of the easier ones to access - otherwise it would be a full scaffold job 😮 This in roof system looks solid but a bit too finicky for clumsy trades to fit and make a hash of the weather tightening, otherwise looks neat 😎
Look s nice and easy if you build in 2 rows. Imagen if hail storm destroy midel one and you have like 4x4 config. You can't removing the midel one with out taking away the one abow or below so this system is more place forget and hope nothing happen!
Curious about the horizontal battens. When water gets under the tiles or panels it runs down and hits a horizontal dam. How does the water exit and how does drying happen with this system? Is the roof fabric draining the water?
literally impossible. in a year they wont even make that model panel anymore. As history in solar panels has shown. And the sizes will change. You'll just have to accept that a panel is broken.
Thats great but what happens if you have the roof insulated - how do you get all the cabling through the insulation and how easy is it to replace a broken panel?
Can't wait till we get perovskite PV on flexible plastic film rolls. Spray glue along the battens, follow along with the roll of PV film, and connect up. A little bit easier. If it fails, just glue a new one on top.
The pitch of the roof is low, so during wind and rain, water will go in between the blue plastic. + there is no vertical wooden structure. The water will get stuck on the wooden horizontal lats and rot. Not a lot of water, but it will give issues in 10-20years. What is also already pointed out, is the panels cant cool down. Even in the UK this seems bad and i wonder if it has influence on the life span of the panel. The rest seems very neatly done and beautiful.
Are you doing it to look fancy or to be functional? Solar panels perform better cold. There is a purpose to mounting them spaced off of the roof. Also makes replacement simple. How hard will it be to remove or replace panels?
this is 100% more expensive then a regular system on rails. Only thing that offsets the price and makes it on par with a regular system is if it's a new roof, and you wont need roof tiles where the panels are.
I think all newc agricultural buildings roofs should be designed to accomodation solar panels at the build or for future installation. Most farms have space to design new barns etc to arrange location to have a roof facing South. It needs government to put this in the planning requirements with the farm building grants.. Any comments.
14*405 Wp = 5670 Wp. Not bad. Cost wise probably the same without installation? And the same for Installation? i think this is very interesting if you do an attic conversion on an old house and raise it by 1 or 1.5 meter to create some new living space. then you need a new roof as well, and make it similar asymmetric and put in three big windows in - everything well suited for the solar panels. however, in Austria it would need a different design, maybe steeper to be better suited for the winter sun and for letting the snow glide down and sacrifice some efficiency in the summer, where you have enough output anyway.
In ontario, code requires a combiner box with fusing/disconnects within 10ft or so of the array, accessible to the person on the roof. This system does away with this it seems, but also there is no discussion of grounding in this video, which is a function conventional rails would have performed. I didn't notice any kind of grounding of the Viridian panels.
Interesting. The next evolution would be to run water pipes under the panels to extract that heat out. Its a win-win: (1) get hot water which is very energy intensive to produce (2) cool the panels to get more electrical energy production and increase panel lifespan!
Wasn't the roof long enough to fit two more panels? I would even have aimed for increasing the width by making the asymmetric shape even more extreme so at least there could have been fitted on 24 panels. Would the system allow to cover the entire roof with panels or is the presence of at least one row of tiles all around unevitable? I would never prefer in roof systems because of the lack of natural panel cooling effect without backside air circulation nor have too much confidence in the waterproofness for several decades.
How do you handle the heat build-up under the panels? If the surface of the system is sealed I would add a perforated flashing at the bottom edge and a fan inside near the top to pull air under the panels. This would create what is known as a back-pass thermal air collector. If the building requires any heat or ventilation, this would provide that and improve panel output through heat mitigation.
I looked for this type of system a little while ago and it seemed nobody was doing it, so started trying to think of a way to do it myself. The consensus seemed to be that it wasn't done because of heat build up reducing panel efficiency. I came to the exact same conclusion as you have. Fans should be installed and the heat harvested(if required). All new homes in the uk are built with heat recovery systems due to how tightly sealed they are. It would be very easy to plumb this hot air into such a system to heat the house. Looks like the pros are at least half way there now. ;)
@@davidleisk580 A couple of tips when designing your system. One fan (i.e air intake) can pull air horizontally up to 12-13m from each side. Also, open-loop back-pass thermal air collectors have the highest efficiency with a very narrow air gap. Higher air volume p/m2 of collector produces a lower temperature rise but higher heat transfer. So if the goal is to improve PV efficiency, go higher volume. However, if you are plugging into an HRV, you can just go with what they are pulling. Keep in mind that the system will increase static intake pressure so a small helper fan feeding the HRV from the underside of the collector would be recommended. In any case, by decreasing the Delta-T for the HRV, you will also increase its efficiency.
I used to be an H&S rep. It was all bollox. All that happened is a man went up a ladder and another was employed to hold the bottom steady. So double the manning levels and costs. The union loved this. Nobody held anything. Jobs were planned with the extra manning and everyone worked as before but finished early or spent time playing backgammon. Productivity was a joke as a consequence.
@@mbak7801 My point was, that nobody should be putting their full weight on the plastic tray at the top of a ladder. Especially when there is a safe alternative nearby :-)
I agree J. Daley. M Bak obviously thought you were talking about a standard ladder. I saw the same as you with the guy standing on top of the step ladders. At least a warning on any building site.
@@peteroffpist1621 and that’s exactly what we want 👍 The concern is if there should be an issue, how involved is it to replace a panel, if it’s a case of stripping the system off panel by panel to get to the faulty one then that’s a big expense. I like the Tesla roof setup where you can lift each panel individually for maintenance or repairs, and they look incredible
@@InTruServ anything in life can happen. A meteor could hit a panel but if it’s a one in a billion risk why bother? That is why we have insurance companies.
He mentioned about undulation of the roof. If you are installing on an existing roof be very careful as most roofs do have undulations. I would only ever install on a brand new roof.
Should be counter battened. Vertical battens first, then horizontal. No where for rain to drain if wind driven rain gets in or condensation drips especially at that pitch.
Really useful vid (as ever - thanks guys!), as I'm just about to press the button on a Viridian in-roof system to coincide with a re-roof. However ... my installer tells me they won't specify the SolarEdge optimisers due to their "relatively high failure rate", and the hassle and expense of replacing, say, 1 panel in the middle of an in-roof setup. Optimisers can't go in the loft - as there isn't one! Any comments from experience of this?
I just DIY'd 3 panels on a garage roof. There is no way to move the top two tiles which taking the pointed ridge tiles off, so I... I have have a bit of an overhang. I figure it will be fine. As long as it doesn't start "fluttering" in high wind.
@@shropshireladoutdoors743 Yes, I have about 30cm of roof around all sides, it's just the position of the rails. The top rail is one roof tile lower than it really should be. But I wasn't going to crack the ridge pointing and then try and source terracotta motor to fix it again!
you forgot to mention that not all solar panels including the latest max outage are possible to be fitted to an in roof design, the kits only fit normally up to 410w pannels 72 cell
Hi, i’m an 18 year old who did a levels instead of going to college to pursue electrical engineering, however i’m looking to become a qualified electrician now. I have seen a company called engineering real results online and they say they can get me fully qualified up to level 3 with city and guilds qualifications through their online course as well as some practical work i would do at their facility to add to my nvq. Would this be enough to get me a job or would i struggle to find a job as i won’t have as much experience as someone who takes an apprenticeship route? Any feedback would be greatly appreciated, Thanks
i found you install the panel in sequence , if someday for any reason i need to replace one of the panel , will i need to remove all the panel in sequence ? or i can just replace that panel separately ?
Interesting! I've seen a couple of these in EU, must be because underlayment has been getting better? In US, the asphalt roofs are standard and obviously this is for higher-end systems. Anyway, I'd imagine in the past you needed the redundancy for water tightness and now you don't? I know that the Tesla underlayment for solar roof is "more of a barrier than typical roof" according to our installers.
I don't understand why new homes don't have solar panels built in from new, I imagined that by now all exterior surfaces would be solar collectors, walls & roofs, panels can be printed to look like brick, slate, wood anything you want to aesthetically they would be fine, and the near zero maintenance of them means less money spent on the exterior of the building, add a ground source heat pump and your living totally off grid. I used to work in civil engineering/construction and some of the big glass-clad office blocks that are in our cities have solar panels built into the glass exterior cladding.
I only hope you can still get this exact size of panel in 10 to 20 years if one fails! Think you need to have a couple of spares. On a new roof maybe worth the effort but can’t see why anybody would fit it to an existing roof. Somebody near me fit a in roof 5 or 6 years ago and it doesn’t look any better in my opinion
