Power Optimisers - What are they? And do you really need them?

[@dtm1303]

I knew nothing about optimizers before this video. Thanks for an excellent and straightforward explanation!

[@GaryDoesSolar]

You're very welcome, and it's comments like this that make the hundreds of hours I put in, all worthwhile - thank you for taking the time to tell me :-)

[@hedzlinzainuddin2501]

Alhamdulillah..Thanks Gary…crystal clear explanation 👍

[@GaryDoesSolar]

* NOTES SINCE PUBLICATION * At 6:34 I over-simplified how the optimiser manages the current. In reality, the inverter first maximises the power from the panel by adjusting the voltage via MPPT, then performs a DC-DC conversion, decreasing the voltage to bring the current in line with the rest of the string. At 7:45, Actually, one or more of the bypass diodes will only kick in if there is a difference in shading across that particular panel. If there is shading across the whole of the panel (as in the diagram) the optimiser should still be able to manage that. And at 14:17 my maths is clearly rubbish - the total production with 12 x 300W panels would of course be 3.6kW, not 4.8kW!

[@CoyoteMTB77]

I’m sure we were all more interested in the different options and scenarios rather than the maths so all good 👍

[@dtm1303]

I love your comment on rubbish math! And love the correction and admission even more.

[@FelipeM741]

This is the best explanation I've found so far, well done!

[@GaryDoesSolar]

That’s such great feedback to receive - thank you 🙏

[@tethysenergy]

We replace on average about 2 x Solar Edge optimisers per year, some on our own installations, some on other peoples. We install about 50 domestic projects per year. We can't really compare this rate to either Tigo optimisers or Enphase micro-inverters as we don't install them. The good thing is that the faulty optimiser can be pinpointed so we don't have to remove half of the array to locate the problem. For the client, Solar Edge will cover the cost of labour and some of the scaffolding costs. For most replacements we can use an aluminium access tower to get up to the roof and locate the fault. The cost of this is easily covered by the Solar Edge warranty. However, the jobs that tend to require a full scaffold are where we need to span over above conservatories or where there is a pitched roof on a lower storey beneath the roof with the panels. For these replacements the client typically does end up having to cover some of the scaffold costs. The more difficult the roof is to access, the more costly it'll be to deal with faults which would need to be factored into any potential client's decision making. There is an argument to install optimisers & microinverters in the loft space beneath the panels. This would make replacement much easier and less costly. We don't do this as it would mean making a cable penetration through the roof beneath every panel. It would also means installing jumper cables between each panel and it's corresponding optimiser for both the +ve and -ve cables meaning more connections in total. Some attics are converted, so for these it's a non-starter to do this and the optimisers have to go on the roof.

[@GaryDoesSolar]

This is great insight from an installer’s point of view and will be of great help to those considering optimisers or microinverters - thank you! 🙏

[@RahulParmar1978]

What's the downside of making a cable penetration through the roof? Is there a risk of rain coming through?

[@tethysenergy]

@@RahulParmar1978 no, your installer should be using a weatherproof cable entry point such as the Deks multi-cable flashing

[@davebutler3905]

Great info! Thank you!

[@notjustageek]

We had a discussion with our installer about Solaredge Optimiser reliability. They were replacing 10 a year over the 20,000 panels they had deployed, so a 0.05% chance of failure per panel per year. Thought I'd mention here since the data for this doesn't seem to be overly available.

[@FrankPloegman]

Thanks for sharing this statistic. My impression is that the failure rate of Enphase micro-inverters is 0,05% over the whole lifespan. If we assume a lifespan of 30 years, that means the failure rate of optimizers is 30x higher than the failure rate of micro-inverters. This does not take into account the certain requirement of swapping the string inverter. Note that I dislike optimizers and micro-inverters equally due to their additional costs among other reasons, so I'm not biased towards one or the other. I prefer the simplest, cheapest, most robust, quickest to install, highest producing system. This is not so easy and in practice and some trade-offs are unfortunately still necessary. On a positive note, it is almost a certainty IMO that solar systems will keep improving in all aspects (e.g. lower costs, less likely to fail, more robust against shade, higher efficiency, etc.).

[@notjustageek]

@@FrankPloegman Yes, this all came up as we were querying the fitness for purpose for the optimisers after one of ours died within 6 months of the installation date. The statistics themselves are interesting, but without more context don't provide much information - if all of these failures are shortly after installation but then drop off significantly for the lifespan of the array then that paints a very different picture to the odd failure every couple of years. Bizarrely, the one optimiser we had which failed (February) returned to normal function in May - we've been waiting for a date to have it replaced. I'm not sure if that might be related to components drying out in warmer weather or whether there was a firmware update which resolved an issue. I think if we have other failures, we'll have the optimisers removed and switch to a different string inverter. There is some shading from the chimney, but it isn't too significant tbh.

[@edc1569]

If we say the average project is 10 panels, then over 10 years they have to revisit 5% of their projects, what a pain.

[@brainthesizeofplanet]

@@edc1569 If it would be that high installer would not do SE anymore - its gotta be less, SE would be out of business if their failure rates were 30x higher than their competitor Also the above statistics leave some question for debate: 1 - was always an optimizer at fault, so a direct technical failure? 2 - were there any connection failures - i.e. cabling issues, broken MC4s etc 3 - How were they mounted/exposed?

[@peteglass3496]

Artisan Electrics put up a video [turn of May/June '23] on larger job they were returning to for putting in batteries, adding a few extra panels and pigeon excluders. On the original solar array one panel had a problem and an SE optimiser was implicated and they found a second problem on another panel while there. Only a single data point but useful to the conversation I hope.

[@jamesmartin2339]

Great video clear and easy to understand. You go over the benefits and downsides of using optimizers. Makes it easy to see what situation you should use optimizers in.

[@GaryDoesSolar]

Cheers James - great feedback to receive 🙏

[@quintonh8026]

Thanks!

[@GaryDoesSolar]

That's so very kind of you - thanks! :-)

[@peterharrison198]

Thanks

[@GaryDoesSolar]

Thanks Peter - that's very kind of you :-)

[@keithjewers7273]

Another very informative video. Many thanks for all your effort that goes into them - as a relative non-expert I find them excellent at helping improve my knowledge and they always provide food for thought.

[@GaryDoesSolar]

That's really great to hear, Keith. Thanks for letting me know! :-)

[@mpmatt3469]

Thank you for your interesting presentation. I have a 14 panel system with a Solar Edge inverter and optimisers on each panel which was installed in 2017. In 2021 one of the optimisers failed but caused the entire system to shut down. The optimiser was replaced, at a considerable cost, but just over a year later another one failed, again causing the entire system to shut down. It was replaced again at a considerable cost to me. a couple of months ago a third optimiser failed but I only lost output from the associated panel, until a few days ago when the entire output was lost. The inverter is still functioning and recording a fault on one panel which would suggest that the optimiser has failed completely. Solar Edge has provided replacement optimisers under their "limited product warranty" but they have not offered to provide any support for the labour cost or scaffolding. It does suggest that the undisclosed failure rate of the optimisers is somewhat higher than the advertised reliability.

[@GaryDoesSolar]

You're very welcome, and thank you for taking the time to share your experience with SolarEdge optimisers. I'm sorry that it has not been a great one, and it sounds like you're very much out of pocket as a result. I would certainly like SolarEdge to be more open with their reliability statistics (like Enphase is) and I'd also like these manufacturers to stand by their products with better warranties over time. To be clear: if microinverters and optimisers are heading towards 50-year operational lifetimes, then I'd expect the manufacturers to be happy to cover *all* the costs in the event of failure - and if they're not prepared to, then for them to explain why not.

[@mpmatt3469]

@@GaryDoesSolar Solar Edge Optimisers are excellent in providing management of shading on solar panels, which is why I chose to install them. They were sold as having a 25 year warranty, but my installer did not tell me that this was a "limited warranty'" which covered only the cost of the parts. In my view installers should be required to provide a full warranty for replacement costs including scaffolding and installation or to offer this as an optional single premium insurance. This would provide a similar protection that is now required when Cavity Wall Insulation is installed where removal costs in the event of failure are also considerably higher than the cost of installation. It is not acceptable to offer a warranty that limits the cost to the replacement part at around £45 when installation could cost an additional £1000. This poorly regulated industry needs to improve or be legislatively controlled.

[@GaryDoesSolar]

@@mpmatt3469 I agree with you. Energy is just as critical as other utilities like water and telecommunications. Proper regulation is the key to stop consumers getting ripped off.

[@lifehealth489]

yep this is what they do, the are Another junk make failing electrical component like the auto industry

[@andylees2940]

Gosh another excellent video, well thought out, presented and most articulate. Great work. Ty Gary!

[@GaryDoesSolar]

Cheers Andy 😀👍🏻

[@Gelp]

Another superbly clear and informative video! Thank you.

[@GaryDoesSolar]

Hi Chris, thanks very much for your kind words! :-)

[@FrankPloegman]

Thanks for your video's, Gary! Their quality is unrivaled. I love your crystal clear explanation and balanced discussion of *all* pro's and cons. I have more than a little technical knowledge, but imagine that even laymen can understand the majority of your video's. I know from personal experience that it's anything but easy to distill so much knowledge on a complex subject into short and understandable teaching. Well done! 👍 I wonder if further improvements in panels, e.g. more bypass diodes, can further reduce the already doubtful net value of optimizers and micro-inverters.

[@GaryDoesSolar]

Thanks Frank - that's really kind of you to say (actually, made my day!) Yeah, I love it when small, cheap technology (like a diode costing a few pence) can have such a huge benefit to a system! I'd imagine solar panel manufacturers looked at the cell layout and figured 3 was the magic number - although looking at half-cell panels, you could have 6 bypass diodes given the layout, and with shingled, potentially even more...?

[@skidogmt]

Agreed! Thank you for this video Gary.

[@hughrattray9354]

Great videos - thank you. I watched this video and part 1 and 2 of the Solar Panel shading. I have a Solaredge inverter and optimisers so I had a look at how they perform with shading. This afternoon one panel was about 80% shaded but still providing over 60% of the output of the unshaded one. So I think this is much better than I would get from the panel if the bypass diodes had kicked in and switched the panel off. Even when the panels are fully shaded I get some power from all the panels. Again, this seems better than if I relied on the panels alone. I could send you the photos of the shading and the screen shots of the solaredge data for each panel. Intriguing subject and fantastic that you are exploring it.

[@GaryDoesSolar]

Hi Hugh, thanks for the kind words. Yes, please - I'd be happy for you to send photos/data through to [e-mail] - thanks! :-)

[@markleygordon9529]

The best explanation I have seen. Thanks.

[@GaryDoesSolar]

Thanks very much for this great feedback, Markley! :-)

[@SnarkySolarGuy]

I am so glad I read the video description after watching the video. I had a lengthy reply ready :D Thank you for correcting the errors and covering the highlights optimization and shading effects on solar modules. Although beyond the scope of your video, it is worth noting that while the strings behave as you say, once connected to an inverter, the MPPT will reduce the effects of shading. Some inverters are better than others at this. Along with optimization, module level monitoring is also an advantage of MLPE. You can see everything you discussed in real-time (or close to it). It is great for digging into the details of system operation, especially when homeowners wonder why their "system isn't working." Thanks again, and take my sub!

[@GaryDoesSolar]

Haha - I'm glad I caught the errors in time then, lest the "Snarky Solar Guy" unleashed on me! :-) Yeah, I wish KZbin would allow video corrections but I can understand why it doesn't. Thanks for subscribing!

[@SnarkySolarGuy]

@@GaryDoesSolar Oh my gosh, yes! Corrections, updates, etc. would be so appreciated. It would totally transform the platform. I am just starting out on this YT adventure with my solar knowledge but some of my videos are already outdated. Thanks again!

[@MrSensible2]

My son & I have very similar solar systems installed by the same supplier. We both have JA Solar 395W panels (he has 12, I have 8) & both arrays face West. Neither of the arrays have shading issues. However I have 4 optimisers & he has none. Why the difference? Well I think we both went with what the supplier recommended. In theory, all things being equal, the ratio of my solar output to his should be 0.666 (8/12) & right now, in Summer, it is. However in the period October to January it consistently ranged from 0.71 to 0.735. It was like I had 8½ panels to his 12. I put this down to my four optimisers. That said, given solar generation in winter is pathetically low, the value of the 'extra' is worth two tenths of bugger all! Had I had my time again, I would NOT have had optimisers put in & saved a few hundred quid.

[@GaryDoesSolar]

Hi there, thanks for sharing your experience with optimisers. This is more important than you think, because people both with and without optimisers will still say they're good (or bad) even though they don't have any means to compare with what the generation would have been in the opposite case. Your case here though, with two similar setups, one with and one without optimisers, indicates that optimisers actually have an adverse effect if there are no shading issues!

[@MrSensible2]

@@GaryDoesSolar Hi Gary, can I suggest a topic for a future vid? The monthly performance of my array has totally confounded my expectations of it. It's a small, west facing 3.16kW array. Notionally it should throw out 2,200 kWh/year with a minimum of 1.68 kWh/day in December & a maximum of 11.45 kWh/day in May. The reality was my December performance was dire at just 0.96 kWh/day (with 3 days of zilch!) but my May performance, at 13.58 kWh/day, was better than anticipated. Indeed June is already shaping up to hit 19 kWh/day! This shift to the extremes (v v bad in Winter but v v good in Summer) has totally changed the economics my solar system. As best I can estimate, I will only reduce my annual grid off-take by two-thirds (not 80%) while a whopping 57% of what the panels generate will get exported to the grid (not the 20% I was expecting). I can't be the only person who's befuddled by this. If you can explain quite what's going on here, I for one, would be grateful.

[@GaryDoesSolar]

@@MrSensible2 Ok, first it's worth trying out the JRC utility as explained in this video, to get an accurate understanding of how much generation you should expect throughout the year given your location and setup: kzbin.info/www/bejne/g5XTgpafaduHgrc. That utility is based on historical weather data. Then, second, I'd say that (as a likely consequence of the climate crisis) the weather we have been experiencing over the last couple of years has just been wild: a lot colder that it should be at certain times of the year, and a lot hotter at other times (e.g. 40+ degree heat wave last summer). Given this, it's worth considering the following as part of a solar strategy: 1. Organise your life so that you're consuming as much of your generation on any given day as you can (washing, EV charging etc.) 2. Use a battery to store the rest (to be used if the next day is not sunny) 3. Choose a tariff with a high or at least reasonable paid export (to get some compensation for everything you can't use) Maybe others have additional thoughts on this?

[@MrSensible2]

@@GaryDoesSolar Hi again Gary. Thanks for putting me onto the JRC tool. I found it last year, before I had the panels put in but couldn't figure out how it worked. The good news is that I now know how to get monthly figures out of it. The bad news is that it outputs much the same data as my other attempts to predict my system performance; it over predicts what gets generated in Winter & under predicts what I get in Summer. For example in May, JRC says expect a total of 332 kWh whereas I actually got 421 kWh. In June, JRC says expect 11.66 kWh/day but up until yesterday, I'm averaging 19.00 kWh/day (& that's with a very obvious layer of pollen that's settled on the array!). I've faffed around trying different roof angles, azimuths, PV types & databases but nothing skews the data to fit what I'm seeing, so I'm going to accept your weird weather/climate change hypothesis! I guess I shouldn't complain as I'm getting way more summer solar than I originally expected. However if you have this issue, you really do need to change the way you 'see' the system economics to being primarily an export income generator & less a reducer of your existing leccy bill.

[@serraios1989]

During the winter months even a few degrees difference in orientation and inclination of the panels can significantly affect the output.

[@OrnateSolarSolutionsLLC]

Great video, love the content. Subscribed. Another useful video would be the pros/cons of having the point of failure on the roof vs at the ground level for both homeowner & solar installer. That would be helpful.

[@GaryDoesSolar]

Thank you, and great idea--I'll add to the wish list :-)

[@lesbadham9671]

Thanks Gary. You are very informative. I am just starting to learn about solar panels and hope to get an installation done soon.

[@GaryDoesSolar]

Cheers for the kind words, Les. And good luck with your solar journey - it's a great time to start as prices are more bearable than even 6 months ago!

[@geoffreycoan]

Thanks Gary, another clear explanation of the pro’s and con’s of the solar setup. Just a question about real-world experience of two of the potential benefits of optimisers from 9:17, dirt on the panels and panel degradation over time. I’ve had a 16 panel FIT array (2 strings) on a Growatt inverter fitted for 7+ years now. Until we had scaffolding up earlier this year to fit our newer GivEnergy arrays I had never cleaned the panels, and in theory over that duration would start to see some panel degradation, but in fact total annual output each year has been consistently around 3mW, with 2020 and 2022 both generating slight more than in 2016 and 2017. So in my experience there hasn’t been any significant dirt-related or age-related power reduction - or any reduction is masked by the annual variation in solar generation.

[@GaryDoesSolar]

Thanks Geoffrey, for your kind words :-) With regard to dirt etc., that's great to hear - I can access my panels relatively easier through several Velux windows we have on the roof. My main problem is to do with birds unloading on the panels! And when I clean I do believe the performance increases, but I don't have hard data to support. With respect to panel degradation, this is documented in the data sheet for the panel model in question, so likely to occur. Perhaps others can comment on whether they see such degradation over several years...

[@geoffreycoan]

@@GaryDoesSolar Ah yes, birds on the solar panels. As I said in my original comment, I didn’t wash my 16 FIT panels at all in the first 7 years of ownership. When I did wash them there was a bit of lichen in places, but nothing too significant. There wasn’t really much in the way of bird mess either. But we then had a further 28 panels installed in January this year with the GivEnergy inverters, mainly on the front of the house and the garage, but then 6 further panels in gaps between velux’s on the back. Within 2 months of installation I noticed that one of the new panels that was directly under the TV aerial had loads of bird poo on it. Of course the little darlings were sitting on the TV aerial and dropping onto the lovely new panel immediately beneath. I rapidly went and bought some plastic bird spikes, stuck them with silicone to the TV aerial and the birds now have to perch on the ridge of the roof but at least they only drop messages on the tiles not on my panels ! And yes, agree about solar degradation over time, its well documented in the panel literature and any new solar quotes. Just commenting that in my experience I’ve not noticed it, or if it is occurring its lost within the annual solar variation anyway. 20 years or so, maybe more significant loss.

[@GaryDoesSolar]

@@geoffreycoan Now that is a LOT of panels! What is your typical generation on a good day? Nice solution re. the birds! 🙂

[@geoffreycoan]

@@GaryDoesSolar When we had the new solar added I went for the principle to get as many panels on as possible, maximise the solar generation opportunity and make the most use of the scaffolding whilst it was up. Despite having had a roof survey done by the installation company they then had difficulty fitting the 6 panels on the back (West facing) in and around the existing veluxes and FIT panels. Managed in the end. So most (22) are on the front, and only as they were fitting them did I realise that I could have added 2 more over the garage and 4 horizontally over the kitchen and porch. Fortunately no export restrictions from the DNO either 😀 Answering your question, its difficult to answer as the FIT array confuses the CT clamps for the inverters as I am generating on the house circuit where they are expecting only demand. On sunny days I end up with negative generation to home and battery to home figures! But, based on the GE reporting the 28 panels typically generate 20-30kW a day. Best so far was 7th April at 48kW.

[@GaryDoesSolar]

@@geoffreycoan Thanks for the extra detail. I had similar problems with my roof space - the Velux windows really constrained how many panels I could get up there (and also the orientation of those panels!) Your generation stats are very good! And being on FiT is just the icing on the cake! 🙂

[@hughbence7339]

And thanks for such excellent research and presentations.

[@GaryDoesSolar]

You’re most welcome! 🙏

[@oebydoeby]

I used optimizers mainly because my panels have different orientation. Otherwise I would have had to use multiple string inverters and i would have lost out one some spots where i could only fit 2 panels on that orientation. This could also have been done with microinverters. So being able to fully use all the space on the roof is a big advantage for me.

[@GaryDoesSolar]

Sounds like you found a great solution to your situation! Thanks for sharing as I think it will get others thinking for their own installations...

[@hammingweight]

I've got tigo optimisers and I'm happy with them. My setup though was constrained by a very small roof meaning that I have 2 x 550W panels facing north and 2 x 550W panels facing south connected in series to a single MPPT. In addition to solving shading problems, optimisers can be useful for weird roof toplogies like mine.

[@GaryDoesSolar]

True, but I think microinverters are better for complex roofs unless you can find a string inverter like the PW3 with many (6) MPPTs.

[@jonwragg3822]

I had a solar edge optimiser fail on my 3.96kW array. Cost was £500 plus because of scaffolding requirement but the optimiser was replaced under warranty. The optimiser that failed was on the panel that produces the most! Array is now 8 years old and the other day produced the second best daily total, so panel degradation seems to be low (just after I cleaned them). Benq panels.

[@GaryDoesSolar]

Thanks for sharing this, Jon. Yeah, a £500 scaffolding cost is quite a hit for a single unit replacement - I'm hoping that scaffolding technologies improve over time, to get those costs down - like this company: www.easi-dec.co.uk

[@nicdensley4104]

Thank you, I'm looking at a string inverter plus optimisers. Very helpful.

[@GaryDoesSolar]

My pleasure, Nic. Thanks for taking the time to watch my videos :-)

[@scallywagII]

I have just replaced 2 optimisers that failed in the eighth year after installation. Their tech support guy said that 2 out of 13 was not bad, he had seen worse. He won't hear much from the satisfied customers with no issues. Found out that Solar Edge have a 12 year warranty on the optimiser, but only contribute to labour and scaffolding for the first five years. My installer quoted £1500 + VAT. I did the job myself after bracing my scaffold tower off the wall and using ratchet straps and wall eye bolts to keep it all steady. The tower also makes cleaning easier. I had begun to have issues with some lichen growing on the panels. Have been told thus is more common in the vicinity of silver birch trees. A large one behind us causes partial shading issues throughout the year, so I am still convinced of the benefit of optimisers for my installation.

[@GaryDoesSolar]

Thanks for sharing your experiences with optimisers. I agree - I’d like to see SolarEdge do more with their warranties - cutting back after 5 years on products they claim to last 25 years or more is very poor.

[@johnwarwick4105]

Lichen is becoming more of a problem over the years. My system is 13 years old now and have been suffering for a few years. No trees anywhere near, interestingly even after cleaning it made little difference to OP. I wonder if the self cleaning coating is wearing off over time as I see a lot of lichen now on older systems

[@guidoformaleoni7870]

Excellent explanation, very simple and easy to understand

[@GaryDoesSolar]

Thank you for the great feedback, Guido! 😀🙏

[@guidoformaleoni7870]

@@GaryDoesSolar You are welcome, I think that besides a solid technical background, you also have great teaching skills. So far, I haven't seen anybody else explaining those concepts in such a clear and understanble way. Kind Regards

[@rodwall2335]

Hi Gary, In your video you indicated that a optimiser bypasses 1 amp when the solar panel is giving 9 amps to give 10 amps. That 10A is then the same as for the other solar panels. The optimiser does not bypass current. Let's say that the solar panel is only producing 15v at 5 amps. 15v x 5A = 75w. What the optimiser does is it converts the 75w power into 7.5V at 10A. 7.5V x 10A = 75w. This then makes the 10A current to be the same as the other good panels. But instead of the voltage in the string being say 30v. it is now only 7.5V. When you add up the total voltage of the string. It will now be less because instead of one panel being 30v it is now only 7.5v.

[@GaryDoesSolar]

Agreed - and I already added a notification correction to the video - I was being too simplistic in the narration at the time, and you have expressed what actually happens very well.

[@andysilvester4836]

Two Solaredge optimisers have failed in 8.5 years on my 12-panel 3.2kWp system. Solaredge have provided warranty replacements but labour and access are extra. On my latest optimiser replacement the scaffolding cost £600. Despite this, Solaredge monitoring of each panel in detail and their customer service has been very good.

[@GaryDoesSolar]

Hi Andy, thanks for sharing your experiences with SolarEdge optimiser failures. Yeah, I do worry about the scaffolding costs. I'd really like optimiser and microinverter manufacturers to further stand-by their products and increase the financial reimbursement levels of warranties. After all, it's just an insurance policy like any other, and so can be costed as such.

[@timallen6025]

Great helpful run through with clear graphics and paced delivery. What more can I write? Thank you 👍

[@GaryDoesSolar]

Your comment has made my evening 😀 thank you! 🙏

[@bobmonztr]

My new array had to be shaded with a stick to keep it from over amping and shutting off the string. 3300w vertical plus snow went over 3800w I saw 4180 on another inverter that I yanked out , crap mppt would clip overcast solar at 60% soc, now with the stick shading 3kw in sun. I am planning to upgrade the inverter to handle alot more pv. Gary do you have any data on which inverter gets the most pv in full overcast? I go 40 days between sunny days here in winter, eg. today was the 3rd sunny day since Nov 7. In a small way I used my idea to put too much solar in a string then purposely shade it to keep the max sunny pv down but boost the overcast pv, the shade stick won't effect power when you can't see a shadow since it is 100% albedo. I am going to add 1 panel to 2 strings and shade it, then march to oct unhook the extra panels. Inverter #3 was a 10kw but failed in overcast so I switched back to the 8kw to get alot more overcast power.

[@b.casual]

My installer specified Tigo optimisers as I'm having panels installed on 3 different roof orientations on a dual MPPT hybrid inverter. I have questioned their inclusion off the back of your helpful and informative videos but feel for the relatively small outlay, the benefits outweigh the negatives. I don't like that there's more to go wrong and there's a small power draw from them but the fact I will be able to monitor each panel from my phone, not be throttled by dirty or degraded panels and the allowance for easy integration of replacement panels are big pluses in my view.

[@GaryDoesSolar]

From what I've read, optimisers are not really designed for use on a string with panels on different orientations, but if it's working out for you, then great - more power to you! :-)

[@deang5622]

​​​​@@GaryDoesSolar don't disagree with your theory, if all the panels are exactly the same model with the same electrical characteristics and subject to the same level of sunlight and orientation then the optimiser will be able to do a better job and deliver more kWh over a period of time. However even with panels oriented in different directions there may still be a sweet spot on the combined IV curve, which can be found by the optimiser. So I think there is still some benefit to be had by using the optimiser but it probably won't be as much as if all the panels are located in the same geometric plane. But whilst an optimiser won't give as much benefit in a configuration where the PV panels are not in the same plane, this is not an argument for not using one. The key factor in deciding whether to use an optimiser has to be based on its cost and how much extra electricity it generates if it is used in the system. That is, is it economically worthwhile? The cost is known, obviously, but the difficulty is going to be is knowing or calculating the extra increase in kW by using it. And that is going to be very hard to calculate before you buy it. And the manufacturers of the panels or optimisers cannot help here (unless they have done the tests with a specific set of panels and optimiser and other initial conditions). You could do it by experimentation and measure the power output in kW (or kWh) from the panels with and without the optimiser. Then you need to get an optimiser on loan and try it out and pay for it after you have experimented with it. An interesting question. (I think this is a long way of saying "try it out"!) and measure it.)

[@deang5622]

If you have multiple panels oriented in different directions where the angle in the horizontal plane is greater than some threshold, say 50 degrees, then I would suggest that you don't connect them all up together, and you create groups where panels in a group are connected together and each group has their own optimiser. And the panels all in the same geometric plane are mapped in to a group. I suspect this may lead to better performance from the system. Of course the downside is the cost of the extra optimisers.

[@b.casual]

@@GaryDoesSolar Tigo has some useful guidance for designing for different tilts, angles, and orientations on their website. Optimisers will be required on all of the PV-Modules to prevent the impedance of power production during periods of extreme shade (mornings and evenings) on a Balanced Orientation (wired in series). Tigo recommends dividing the string into two separate strings in series going into separate MPPTs: Each string would produce enough voltage for the inverter to start up and maintain the MPPT specified voltage range - along with enough current (power) for good production. Because all modules on the separate strings face the same azimuth, the irradiance per panel is nearly equal (unless shaded), ensuring the string voltages and currents are always contributing to power production.

[@brainthesizeofplanet]

​@@GaryDoesSolar SE works ok with it, the Designer will quote you a percentage loss for it - I have seen about 1-2% so far. Tigo might not be the best option here as it's basically only doing mppt at panel level without DC to DC

[@buddywheels]

Excellent video once again Gary, thank you. I watched for general interest as we fitted Enphase micro inverters to our AC coupled GivEnergy system some time ago. Feels like exactly the right decision for us and we couldn’t be happier with system performance. However, we learned very quickly in our research that “solar” isn’t a “ one size fits all” game. Thanks again 👍

[@GaryDoesSolar]

Thanks Steve - I had been wanting to make this video for some time (to complement the microinverter video I made). Great to hear your experience with microinverters has been good :-) And I totally agree with you, every person's situation will be somewhat unique, with different requirements.

[@harism5589]

Thank you Gary for creating this video blog and sharing it! Very helpful. I assume either SolarEdge or Tigo string inverters will work with or without optimizer. Looking at Tigo web site I got impression, I must use optimizer. Since it does not clearly say the inverter can be used with out optimizer. Also Tigo "hybrid" inverter says "can use with or without battery connected". If that is true, it can be used like "string" inverter.

[@GaryDoesSolar]

You're very welcome :-) SolarEdge Optimisers are required for SolarEdge inverters, but Tigo optimisers are optional for any other solar installation. Yes, a hybrid inverter, although designed to accommodate a DC Coupled battery, does not have to have one connected.

[@hughbence7339]

We are planning a new installation which will have a variety of shading issues, both hard and diffuse. We have had a few discussions about optimisers and micro inverters. One of our quotes proposed using Aiko panels with optimisers. Have looked at the Aiko details they claim to have cell level optimisation for partial shading and as such should not need any optimisers. There are a number of KZbin videos demonstrating this. Have you done any research on these panels that claim to be unique?

[@GaryDoesSolar]

Hi Hugh, yeah, I’m currently researching the latest and greatest with solar panel technology and products. Video out in a few weeks all being well 😀

[@tonyhill4984]

Hi Gary, Ace vids mate, just to confirm I understand, I have a 4 kw system of 12 panels facing directly south and 4 facing north so the four will be dragging the 12 down, is that correct? OK so just viewed your micro invert vid, it confirms, thanks mate.

[@GaryDoesSolar]

Hi Tony, thanks for the great feedback! :-) Now, it depends on how the panels are wired to your inverter. Most inverters support two strings, and it's highly likely your installer will have wired the South and North arrays to separate strings, so no issues with one array dragging down the other...

[@glennmartin6492]

OT: Has anyone developed a mounting system for PV panels where they're attached to the railings on one side with hinging pieces and on the other with a latch release? This would allow a technician to unlatch the panels and swing them out of the way which would be ideal to access a problem in the middle of a panel array instead of removing several panels to gain access.

[@GaryDoesSolar]

Hi Glenn, I like your thinking on this. I'm not an expert but having an easy access mechanism could be a good thing... it can't add much to the cost, surely?

[@Tom-hb1no]

Gary - great video and explanation - would optimizers like tigo work with or be advisable to add in conjunction with Tesla Powerwall 3? The benefit being shading and monitoring? I do realize PW3 has 5 or 6 inputs so less of an issue in general

[@GaryDoesSolar]

Hi Tom, thanks for the great feedback! Yeah, Tesla have really thought about it, and depending on which country you're in, you can get a PW3 with 6 inputs, negating the need to have optimisers - not least because the bypass diodes already do a great job!

[@amruthaandrews]

This is a really informative video. I would like to know if there is a shading on only one panel and there is 7 more panels in the same string. Do we need optimiser on all of them or just one.

[@GaryDoesSolar]

Thanks for the great feedback. For the answer to your question, it depends which manufacturer of optimisers you want to use. If Tigo, yes, you only need to put them on panels which will experience shading. If SolarEdge, they mandate an optimiser on every panel irrespective of shading potential on the panels.

[@jszlatki]

Gary, many thanks for the video. It was a great summary

[@GaryDoesSolar]

You’re very welcome - thanks for watching 👍🏻😀

[@chaswinder]

Hi Gary, another great video. Just wanted to query your sums @14:12 - 12 x 300W panels would be 3.6kW peak production, not 4.8kW :)

[@GaryDoesSolar]

Thanks Chas - and oh no! You're right - I used animations from a previous video, which had 8 panels, not 6 - oops - I'll add a correction to the video. Thanks for spotting!

[@chaswinder]

@@GaryDoesSolar Maybe just edit the audio to say 400W panels instead of 300W ? Might be easier, just a thought.

[@GaryDoesSolar]

@@chaswinder I like your thinking - unfortunately, KZbin doesn't allow any changes to videos once published - you can basically only blur parts of the screen or mute/delete sections. I've added a correction action note at that point in the video, which should hopefully do the trick - thanks 👍

[@haysdb]

I’m glad someone pointed this out. I did rewind 3 times to make sure I heard what I thought I heard.

[@CoderTronics]

Thanks some things to consider and investigate

[@GaryDoesSolar]

You’re most welcome 🙏 😀

[@coniow]

One point worth noting with Solar Edge Optimisers is their ease and safety for setting up: When a panel has full sun on it, it is producing electricity, a full string produces a hell of a voltage, potentially life-threatening! This makes connecting up panels to the inverter a potentially hazardous operation. The Optimiser restricts that to 1 volt. Ten panels connected = 10 volts. If that is measured at the Inverter, you know that all panels are connected and operational. If 9 volts, then one is out Etc. When the array is either disconnected from the inverter, or the inverter is turned off, the same holds true: 1 volt per panel. This makes it a lot safer for Firemen, and for fighting the fire: Spraying water on to live power cables will not put the fire out!

[@GaryDoesSolar]

Thanks for sharing this - I think over time, more and more countries will mandate optimisers/microinverters on properties.

[@WolfClinton1]

Thanks Gary, that was very helpful. We are about to commit to expanding our very early (Solartube) 4Kw system with a 5Kw on a different roof with a chimney, I was dubious as the installer quoted for Tygo optimisers. You've made my mind up to go for it.

[@GaryDoesSolar]

You’re most welcome. All the best with the install, and I’d love to hear how things go. Cheers!

[@PhotoWaVolt]

Highest quality thank you

[@GaryDoesSolar]

That’s great feedback to receive - thank you 🙏

[@mark_just_mark]

Really detailed view of all the options… I choose no optimisers based on ‘No shading’ and ‘reduced failure risk’ by not having another element on the roof. Watching KZbin solar installers doesn’t help with the potential failure rates as I’ve seen two failures, one panel and one optimiser! 😂

[@GaryDoesSolar]

Thanks Mark. Yeah, shading is certainly the primary driver for fitting optimisers, and so if there are no shading issues, then the financial case weakens dramatically...

[@SPdesi1]

Thank you Gary, you cleared my doubts on using optimizer, very well explained.

[@GaryDoesSolar]

Great to hear that my video was informative for you :-) Thanks for taking the time to tell me!

[@devroombagchus7460]

Thank you very much. Very clear and valuable.

[@GaryDoesSolar]

You're most welcome - thank you for watching :-)

[@NiceGamingHU]

@GaryDoesSolar, can you help me if i have to select 600W or 450W opzimizer is enough for a system, where all opzimized panels are DAH 410W panels. Optimizer is Huawei PV 600W or as asked the same but with 450W? I'm not sure i only need to check the W rating of the solar panel, or some other detail from the datasheet? Thanks in advance for your feedback!

[@GaryDoesSolar]

Unfortunately, l'm not in a position to provide individual advice (not least because of potential liability issues, even if that advice is given free - such is the world today). You're best to speak to an installer for such advice, or post a comment onto a solar forum (e.g. this one in the UK: facebook.com/groups/2197329430289466). Good luck!

[@NiceGamingHU]

@@GaryDoesSolar hehe world is a crazy place for sure waaaaay to many freedom, people dont know what to do with themselves thanks for the tip, joined the group and hopefully someone will help me to understand which one to use and for what reason why i asked is, i just have my system installed, and in the offer it was 600w optimizer, but now i see in the system monitor that they installed 450w i did not pay yet, so i dont worry much, just want to understand if my system will make less if i settle for 450w and ask for better price, or should i insist on them change to the 600w which they offered

[@moez2388]

great information. Thank you for sharing

[@GaryDoesSolar]

You're very welcome, and thanks for the great feedback! :-)

[@diwright]

Hi Gary, and thanks for your video's. I do find them extremely informative. At 11:49 you show a screenshot that appears to come from the Solar Edge monitoring app. Would you happen to know how you get this type of layout? I have access to the same tool (supposedly....) but the layout I see is nothing like the one you show, which to me seems much more detailed. Any advice on this would be much appreciated. Thank you.

[@GaryDoesSolar]

Hi Dave, thanks for your kind words! :-) Now, I searched the Internet for suitable SolarEdge dashboards and picked that one. What you could do is write to them, enclosing a screenshot in your email, and ask them how you can get the same functionality... Cheers, Gary

[@stevenshaw9314]

Great video. What is the average line loss for an optimizer? You mentioned adding optimizerto an older system, as I have a 10 year old system with 46 Sunpower panels split into 7 strings between 2 inverters, the system is starting to show a several percent loss in efficiency. A couple of strings do have shade loss in the mid afternoon until shutdown of about 10 percent. The question then becomes, do I look to add optimizers, and will the increase in production then offset install costs (US labor rates) to calculate the next ROI? On a side note, to help prolong inverter life, I had my inverters placed in the basement. This has had a few benefits, the inverters run much cooler and they stay cleaner. Yes they dump a minor amount of heat into the basement, but my heat pump hotwater heater negates that issue. It also helps provide air flow and some dehumidification when the heater cycles. Lastly, I have been trying for years to find data on the "R-value" from adding panels to a roof? As my system covers 50 percent of the total roof and over 75 percent of the roof with direct sun the heat load offset is significantly increased.

[@GaryDoesSolar]

Hi Steven, thanks for taking the time to comment. Unfortunately, l'm not in a position to provide individual advice (not least because of potential liability issues, even if that advice is given free - such is the world today). You're best to speak to an installer for advice, or post a comment onto a solar forum (e.g. this one in the UK: facebook.com/groups/2197329430289466). Good luck!

[@stevenshaw9314]

@@GaryDoesSolar thanks for the reply. I commented mainly to give discussion on some of the variables. Great videos, it's appreciated.

[@masonfamily2363]

Informative and clear. Thanks Gary!

[@GaryDoesSolar]

You're most welcome. Glad the videos are helpful to you :-)

[@d.b.cooper1]

Again thanks for explaining this Gary! Our installer recommends 5 tigo optimisers (£60 each) out of the 11& a £300 tigo gateway. I don't mind but I just hope the surveyor did his calculations right & was conservative as wouldn't want anything dragging it down due to a chimney neighbours house to the east shading early morning sun. Going via big company so their tech/pre install team informed us of this which is disappointing as the surveyor mentioned nothing to us, slightly harder having a detailed convo via/email with people who aren't too sure on things. Alas they're knocking 50% off the additional cost which makes it worthwhile Do you think it would be worthwhile putting an optimiser on all of them even if not needed?

[@GaryDoesSolar]

My pleasure and thanks for the detail around your installation plans. I can't advise you on what to do, but if you don't have shading you may want to keep everything on the roof as simple as it can be. My own roof doesn't have shading and I decided not to have any optimisers on the panels for that reason. My panels are performing flawlessly. Good luck with whatever you decide! :-)

[@brentfrank7012]

Gary, I know my first two panels in the array are shaded in the morning. By running all of the panels in parallel I can separate those two from dragging down the other eight units. No optimizers.

[@GaryDoesSolar]

Yes, a parallel arrangement can certainly help solve shading issues 👍🏻

[@wesa665]

At $50 per optimizer does the slight efficiency change justify the cost? I’ve for 12 panels that for about 2 hours a day are subject to tree shading of various degree. $600 for 12 optimizers. How many years will that take to recoup?

[@GaryDoesSolar]

It’s a great point. I’m not sure if optimisers are worth it 🤷‍♂️

[@peteglass3496]

That's great, I'm slowly learning. Things are not at all obvious.

[@GaryDoesSolar]

Hi Pete, you're not wrong - it can be a bit of a minefield, trying to figure out what information is correct and what's not. Hope my videos shed some light on the former :-)

[@erfquake1]

Gary, could you please make a video on potentially damaging weather phenomena affecting solar panels, like hail and lightning?

[@GaryDoesSolar]

I'll add to the list, but I tend to choose video topics that would appeal to the most.

[@johnreid725]

Hi Gary, nice video. I see you have a GivEnergy inverter from your video. Do you actually see your bypass diodes cutting in ? I never see the GivEnergy inverter giving up voltage to maintain the current. So my string collapses with small amounts of hard shading. ( No optimisers)

[@GaryDoesSolar]

Hi John, glad you liked the video :-) Yes - I have a 5kW Hybrid GivEnergy string inverter. Now, I don't have any shading issues on my panels, so the bypass diodes will never kick-in, but I am planning some shading tests at some point - I also have a spare panel to do these tests on as well :-) Let's see how my kit performs...

[@johnreid725]

@@GaryDoesSolarLook forward to it, sounds like we have the same kit. For refrence, my half cut cells are in a 6 panel string. Hard shade on 1 half of a column drops current to around half, as expected, but if both halves of a column see shading, or more of the panels I get a drop to lowest denominator current. So PV drops from 2kW to circa 1kW, then around 300w. Stays there all the way to all panels shaded.

[@johnreid725]

@@GaryDoesSolarJust found something interesting. If you do the test with a piece of cardboard directly on the panel, you get the expected results. However with hard shading ( so still some illumination) then the diodes don’t seem to cut in with the GivEnergy mppt

[@GaryDoesSolar]

@@johnreid725 Hi John, did you mean to say "diffuse" instead of "hard" shading in your text above? If you did indeed mean hard shading, I would not expect any illumination?

[@johnreid725]

​@@GaryDoesSolar Hi Gary, to expand, in case definitions differ. The first case was with zero illumination, ( Cardboard directly on panel). And I was defining hard shade as a neighbours roof, where the shade is uniform, with the roof being between 3 and 10 metres away as the roofs diverge. For context, as above, the current through a panel where both halves of a half cut column are shaded drops from 9 amps to 0.9 of an amp for the whole string. I was thinking hard ( close solid object ), soft (distant tree) . Perhaps it is a s simple as the MPTT sticking with the local maximum, as the shade isnt "hard enough" The thing I dont fully understand is that most internet articles discuss the behaviour of the diodes under shading, as if they act independently. I believe that the behaviour of the string MPPT is crucial in deciding if current is maintained, forcing bypassing diodes to operate, or voltage is maintained, leaving the diodes not bypassing. This is seldom mentioned ? ( Your videos in contrast are much more whole system :-) )

[@haldo691]

I have 4 optimisers to install on a 4 panel string that are either side of an east / west pitched roof

[@GaryDoesSolar]

Can you expand on that?

[@robwalker6167]

It's a sobering read from Mark. Neither SolarEdge or Tigo fill me with confidence, yet it seems that on an installation with shading and/or split aspects then solar optimisers make a lot of sense. There's not a lot of choice in the market so is this Hobsons Choice? Tigo seems to be the best of them, but whatever happened to integrated solar optimisers in the panel itself aka Jinko PERC MAXIM? Great work Gary and thanks for the links to Mark's site in Australia

[@GaryDoesSolar]

Thanks Rob - yeah, it's murky world with optimisers! I believe Sunpower do an integrated optimiser (or microinverter?) but those panels are the most expensive on the planet :-/

[@larseiriksalte9357]

If I have 8 panels in one direction, and 3 in another direction. And if I only have optimizers on the group of 3. Is it true that the group of 8 panels will not have reduced production because of the optimizers on group of 3. But the the group of 3 will have reduced production, when the group of 8 is in shading? Planning on using Tigos

[@GaryDoesSolar]

As you can imagine, I receive a large number of questions about specific situations and needs, and unfortunately, I can't respond to them all individually. However, there are several solar and battery groups online, such as this one in the UK, where knowledgeable members are often happy to provide free advice and support: facebook.com/groups/2197329430289466. If you live in the UK and you'd like more personalised guidance from me directly, I offer a "Chat with Gary" service. While this isn't a free option, it does allow us to dive into your specific circumstances in detail: garydoessolar.com/chatwithgary/. Best of luck in finding the answers you need!

[@brentfrank7012]

Hi Gary, Hooking up an array of ten 400 w each panels. Going into a EG4 18k hybrid inverter. Then EG4 battery bank. Two or three panels on the east end of array will be shaded in the morning by a tree. Should I add optimizers to just those three? What would be the point in doing all ten when the seven panels are clear of shade all day? Thank you very much.

[@GaryDoesSolar]

Hi Brent, unfortunately, l'm not in a position to provide individual advice (not least because of potential liability issues, even if that advice is given free - such is the world today). You're best to speak to an installer for such advice, or post a comment onto a solar forum (e.g. this one in the UK: facebook.com/groups/2197329430289466). Good luck!

[@codetrade6437]

I have a question what if i have a solar panel with same voltage but 150 watt less than other panels then can optimiser on this panel can allow my other panels to produce full power?

[@GaryDoesSolar]

I think that's a question to ask your installer. There could be other factors at play...

[@codetrade6437]

@@GaryDoesSolar there’s none actually i have a very tight budget so that I don’t have solar panels with same specs, i have 4 solar panel of 530 watt, 1 solar panel 400 watt and 1 solar panel 450 connected in series, i know that because of these 2 panels my system is not working on its optimum. So as i’m trying to learn about solar optimizer and if it can help my solar panel than i try to buy one and i will install it by myself. Thanks for your reply. Your videos are amazing. By the way can you make a video on it i think it will be a great experimental video.

[@daviddb2528]

At last a solar presentation not full of excitable hype and blah-blah. Consider yourself subscribed. An optimiser failure on our 2015 4kw solaredge system bought me here so just another single point of data from someone who is absolutely not a techno-pup. The solar edge app has allowed easy identification of the failed unit and access via scaffolding tower from our excellent local installer was only thwarted by high winds. My non technical mind has been swayed by tge advantages optimisers may give as dirt accumulates on some panels. Particularly as we are in a very coastal location and salt accumulation is anecdotally claimed by those of an agricultural persuasion to be as high as one ton per year per acre. Perhaps coastal installations is the subject of a whole new video. Certainly the luminosity of lighf reflected off the water is a plus. Anyway keep up the good work Gary! PS Dang! And then the Immersun unit failed this week - replacement by an Eddi has blown a gaping hole in this year's payback caculations. That and Good Energy going ,via smart meter info, to paying foe exports on actuals rather than a caculated 50% of output. Sorry to rant on but.....pfftt!!!😮😢

[@GaryDoesSolar]

Hi David, thanks for sharing your experiences and also for your kind words. Given you had a failure a few years ago, would you say your overall impression is good, or would you have preferred to have gone with a different inverter?

[@daviddb2528]

@@GaryDoesSolar Hi Gary! Funnily enough, back in 2015 when the system was only 6 months old the main Solaredge inverter in the garage did fail and was replaced under warranty, the fitter said they had had a complete rash of failures locally hence the upgraded replacement item. I was just pleased the guarantee worked as advertised. As for the diverter/prioritiser (was Immersun, now Eddi) again the fitter said a 'fair few' of the mark I version as he called them had failed , a new improved version was available from Immersun but we just went, as bog standard consumers , with the local company hence Eddi. I take you view that the ROI on such a device is arguable but as two dotty old pensioners who are not mega price sensitive the big advantages for us is , firstly ,that the hot water is almost always there without any intervention or input from us. (Do I like getting into a shower and finding I forgot to make hots). Secondly the new Eddi app is much improved for us in deciding when to go and switch a dishwasher or some other machinery on plus if needed I can remotely boost the hot water production even when I'm out and about fishing for example. Thirdly this is our first ever house with a walk in airing cupboard. Over the last nigh on fifty years Mrs B has measured her progress in life by the stature of her kitchen and her airing cupboard and to walk into one that is always warm just floats her boat. This is all a long winded way of hinting that ROI is not the be all and end all for all of us and no doubt we are not unique in that way. More about the way we choose to run our lives . Even the opportunity cost argument bears some scrutiny. I see now our 4kw system cost in 2015 , £6350 including scaffolding and Immersun. To date we've had back £5177.87 in FiT payments and produced 34.8 Mwh of lekky an unknown but substantial amount of which we used ourselves. The same year I 'invested' in two funds, Scottish Mortgage and Woodford Equity Income. Scaling those investments to match the pv solar system cost one returned me (back of fag packet) £18000+ and the other £3000+ . Pffftt!! And yet, and yet, out of the three 'investment' I've had much much more engagement and pleasure from the solar system and a toasty warm airing cupboard !! Just need Tesla battery car prices to come down to move onto the next stage. Really enjoying working through your videos. Apologies for banging on for so long like the garrulous old git I am.

[@GaryDoesSolar]

@@daviddb2528 Thanks David - such a wonderful comment - I really enjoyed reading it - and you're right - it's not always about the ROI 🙂 I hope others reading it benefit from your experiences too!

[@jonathancotterell6301]

I have Enlighten micro inverters on 2 strings of three panels. Unfortunately the Enphase collector/gateway seems to have failed -just flashes ref lights - support said its out of warranty. New ones are £600! Only benefit of replacing is to be able to 'actively manage and monitor' the panels. I'm struggling to see the cba of replacement. Thoughts? Have I missed something?

[@GaryDoesSolar]

£600 is a fair whack, especially when it's just to get you back to where you were. Assuming the solar array is performing as it was before (same generation as this time last year, or in line with PVGIS) then might be worth waiting for the day (that may never come) when the array performance drops...?

[@mutton_man]

My roof is unshaded but i do have a somewhat large antenna that create some shading on panels. Would it be worth getting optimisers for that?

[@GaryDoesSolar]

Now, I can't give advice for individual circumstances (not least because of liability issues, even if that advice is given free) but if it were me, I would first look at moving or removing the antenna. Otherwise, I'd certainly be looking at either microinverters or optimisers if the shading was going to affect more than say 3 or 4 panels...

[@richardhogben3776]

very good video, thank you

[@GaryDoesSolar]

Cheers, Richard - thanks for taking the time to let me know :-)

[@JouniKyyronen-nv1ep]

what if half self panel bottom is broken, can it just be used half power or should solder off

[@GaryDoesSolar]

Hard to answer without knowing the detail… cheaper just to replace the panel?

[@keithbishop9126]

I installed a SE system, One optimizer failed about 2 years later, at 7 years two more failed. These seem like a weak link in the system. Changing out is a real pain ! ( I had to remove most panels to get to the failed one) Think about easy access if possable.

[@myluxuryworld]

Thanks for another well researched video

[@GaryDoesSolar]

You're most welcome! Thanks for watching :-)

[@rudolfespinola9231]

Very interesting video!

[@GaryDoesSolar]

Thank you! 🙏 😀

[@basilkearsley2657]

For the example of string inverter and optimisers would not a failure of one optimiser impact all solar panels as you don’t know how it will fail. It can fail safe, impact only one panel. Or can fail unsafe and impact all the panels

[@GaryDoesSolar]

They’re certainly designed to fail safe, but you’re right. They might not…

[@mjbastian3677]

So the solar system with optimizers, you still need a mppt?

[@GaryDoesSolar]

Yes

[@jamesthurgood8083]

Excellent video

[@GaryDoesSolar]

Thanks for the great feedback, James :-)

[@OutdoorsWiththeKids-zm9dt]

I wish you would have addressed battery storage. There inefficiencies that come with switching between AC and DC. Switching to AC at the panel and then back to DC at the battery and back to AC for the home is not ideal.

[@GaryDoesSolar]

Don’t worry - I did address these aspects in this video: kzbin.info/www/bejne/rmmWpWSfeLKLrtksi=xViJYjdm2cl44lmJ Although DC Coupled batteries are slightly more efficient, in terms of an overall daily modelling picture, there’s not a lot of difference, so I would choose AC or DC Coupled based on the other relative benefits.

[@timcat1004]

I have four 330 watt panels that I use to charge an Ecoflow power station. The panels are wired in 2S2P. The other day one panel suddenly stopped working and I lost 50% performance. The panel that it was in parallel still shows amps using my amp clamp and the suspect panel shows zero amps. I tried the panel in a series string of three and I get zero amps. If I take the plus and minus of the bad panel and connect them together I get 9 amps the panel is rated for. I'm thinking bad bypass diodes. What do you think. I have ruled out connectors.

[@GaryDoesSolar]

Sorry that you’re having issues with your setup. Unfortunately, I’m not in a position (not insured) to provide individual support/advice. You may want to contact the manufacturer direct. Good luck resolving 👍🏻

[@harism5589]

Can you please create video on "how to add more panels" if already installed are not enough. After I bought electric car, now my consumption is gone up. This is reason need to add another 5 kW system. I do not want to "replace" existing inverter already installed 16 panels. Because I may loose warranty on it.

[@GaryDoesSolar]

I'll add to the list of future video suggestions, but it's a BIG list... You could always add a second inverter (ideally the same manufacturer so just one app to control both)...?

[@sparadonja]

Gary, thanks for this really great content and clear explanation you do. As it is in my nature I double check all your claims with other sources. And I can say you highly credible solar expert. However I found some ambiguities which are more related to global markets. As an example warranty periods that solar vendors give. While Enphase gives 25years warranty for US and Canada (+ labor reimbusment), it gives only 10 years for EU. I know warranty doesn't mean failure rate, but maybe SolarEdge 12year warranty for their string invertors also reflects in minimal risk for failure. For their optimizers they offer 25years. Any thoughts?

[@GaryDoesSolar]

Hi Grega, great feedback - thank you! :-) You're right about warranties on a lot of products these days - anyone buying products should really check the warranties carefully. But it's a bit like reading end-user licence agreements with software - nobody does! I'll check out the Enphase warranties for the EU again...

[@sparadonja]

@@GaryDoesSolar I checked again Enphase support page, where i can find different warranties depending on EU member state. Big markets such as Germany or France have full 25Y warranty including labor reimbursement costs, which is similar to US and Canada. However smaller countries do not get same level of warranty and support (yet). Warranty also varies on microinverter models and date of installation.

[@GaryDoesSolar]

​@@sparadonja Very strange that Enphase have varied policies in different regions! Certainly pays to read the warranties thoroughly, certainly! Thanks for checking this out further 🙂

[@nightmareinaction629]

6:40 thats now how an optimizer works. Your talking about a bypass. The way most work is they are dc dc step up / step down converters. So lets say all solar panels putput 30v 10 amps and shaded one maybe 28v 8 amps. What the optimizer will do. It will either step down the voltage down to maybe 20v and output 10 amps. Or the other optimizers will boost the voltage to 32v and putput 8 amps instead

[@khachoang1719]

After listening to your explanation, I still don't get why having one or few optimizers on the un-shaded areas might help maximizing their power output since the current at the shaded area is being bottlenecked at 8-9A?

[@daninbar3446]

I think the point is that the optimizer solves the bottleneck by increasing the amps and lowering the voltage of the shaded area.

[@khachoang1719]

@daninbar3446 I was wondering about the case where he draw optimizers elsewhere, not where it is shaded but still reap the benefits somehow.

[@franklyden]

Meget god video. Tak fordi du laver dem

[@GaryDoesSolar]

Det er mig en fornøjelse - tak fordi du så med! 😄

[@christopheclique134]

Bonsoir que pensez-vous des optimiseur Tigo car je voulez installer cela suite à des ombrages sur différents panneaux

[@GaryDoesSolar]

Bonjour Christophe, si vous recherchez un optimiseur rentable, la solution Tigo semble très populaire. Et vous n'avez pas besoin de les avoir sur tous vos panneaux, mais uniquement sur ceux qui présentent des problèmes d'ombrage. Notez cependant les points de ma vidéo : vous ajouteriez de la complexité à votre toit, ce qui pourrait entraîner des coûts (non inclus dans la garantie) en cas de panne.

[@christopheclique134]

@@GaryDoesSolar bonsoir merci beaucoup votre retour je vais voir pour effectuer cela les mois suivants part contre je dois acheter le kit de suivi avec ou juste les optimiseur fonctionneront parfaitement sur les panneaux merci 👍

[@Mywhtjp]

I have 2 arrays, (both ground mount) and heavily shaded for the morning and late afternoon. I wonder if I can "try before I buy" option..?

[@GaryDoesSolar]

You could certainly purchase a handful of Tigo optimisers (around £50 each) and try them on those panels with shading, then see how they perform over time?

[@caterthun4853]

How do you access these electronic nunits on a roof when one fails...seems should be easily accessible.

[@GaryDoesSolar]

In the UK, scaffolding is required, which can be expensive.

[@slimanus8m]

Why do you think both solaredge and enphase aren't used in the RV market? they seem to have the same features as the rest of themץץlike victron and such

[@GaryDoesSolar]

Not sure. I don't know much about the RV market - might be too small a market for those companies perhaps?

[@ModernUkrainianHomestead]

thanks. however, you did not cover the fact that optimizers allow you to put panels on different slopes and azimuths, and have them still connected to that same MPPT of your string or hybrid inverter. for me that is probably the biggest benefit of them, and I'm going to install Deye optmizers soon when they arrive, together with adding more panels to additional roof slopes that were panel-free before.

[@GaryDoesSolar]

What you say is true, but it's a limited benefit and not one that many installers recommend, from what I hear.

[@ModernUkrainianHomestead]

@@GaryDoesSolar it's the most benefit, since I now can add 3kW of solar easily without losing any efficiency and without any major system rework.

[@GaryDoesSolar]

@@ModernUkrainianHomestead Hopefully your inverter is one that can accommodate such a configuration (i.e. global MPPT scanning). I'd be interested to hear how this goes... thanks!

[@ModernUkrainianHomestead]

@@GaryDoesSolar it actually already does. Since it's Deye 10kW 3 phase, and currently I have 6+7 panels paralleled strings on its MPPT1, and MPPT works perfectly balancing the power output from various size paralleled strings (currently all the panels are on same 33 tilt and -22 azimuth), I've been doing many tests with it. But optimizers will allow me to get more panels added there to the other roof side (55 tilt and 68 azimuth) to cover the evening peak better, and also due to high tilt it will be so much better for winter (better winter angle to the sun, and no snow build-up).

[@GaryDoesSolar]

@@ModernUkrainianHomestead Sounds great - and good to know, thanks! 😃

[@mohdahmed8911]

How technically did the optimiser reduce panel voltage to 1 V during the fault or in case the inverter switched off ?

[@GaryDoesSolar]

I don't know the answer to that. Worth contacting one or two suppliers as they may have different approaches...

[@davethefab6339]

Great stuff👍

[@GaryDoesSolar]

Thanks Dave :-)

[@adrianmaguire5459]

This sounds silly to ask, but would optimisers help if panels are mounted flat on a flat garage roof?

[@GaryDoesSolar]

Not a silly question at all, and it all depends whether there is any shading on that roof, bearing my mind the panels will be tilted.

[@alf699]

Good explanation, but you didn't talk about cost difference. Example..I have a 24KW Solar system with 60 panels at 450W. I can get my three 8.2KW Fronius Primo String Inverters for around $7,500,- while the 450W enphase micro inverter would cost about $14,700,-. That's close to double the cost. There are a lot of plus and minuses on both sides when it comes to String Inverters/Micro Inverters/Optimizers. I can just talk from real world experience. In 20+ years we are now on our 3rd system. 1st one was a 3KW system with a quality string Inverter installed under the Eve outside...never a single component failed or showed noticeable degradation in 10 years. We sold the house and I do believe that it's still working (now 20 years) as I drive past the place fairly often and I can tell that the original panels are still on the roof. 2nd system was a 4.2KW hybrid system with the Inverters installed in the rumpus room. !0+ years absolutely no issues and after 10+ years I could not tell any degradation. In that period I went twice on the roof and gave the panels a wash-down with pure water, no detergent. This system has now been upgraded to 24KW. I directly know of 3 users of micro inverters that all had one or more issues with them, including one within weeks of the installation. Were they just unlucky?..possibly. Have I been just very lucky..also possible. But I also put the odds in my favour by selecting quality and proven components and reputable installers.

[@GaryDoesSolar]

Would be interesting to know if the microinverters in question were Enphase IQx series. I don’t really rate other microinverter products.

[@alf699]

@@GaryDoesSolarThey are/were Enphase, but which model I wouldn't know. This was at least 5 years ago with the one where failures happened shortly after the install. He had a 10KW system installed and there were issues with 3 or 4 panels, which took multiple months to be resolved. Although that says more about the Installer then the product itself.

[@scott-lc8xc]

Anyone have any input on using Tigo Optimizers for a Motorhome Rooftop Solar Array? Would be 12 200W panels which would be in varying mounting directions do to space limitations on the roof. Installer is recommending them.

[@GaryDoesSolar]

Hi Scott, I don't have an answer for you on this topic, but perhaps others do...

[@MR-ub6sq]

1:44 How can such long wires be prevented so that the conditions do not cause wear of their surface insulation and eventually a short circuit and fire? If the conductors scratch that rough brick roof over time due to temperature changes and wind, then structural safety has been neglected. It is definitely not enough that the wires are "nicely" hidden under the panels.

[@GaryDoesSolar]

Valid point. I don’t speak for the installer of this particular installation but I’d imagine they would tie-wrap the cables before laying the panels.

[@NackDSP]

String MPPT optimizers have a wide voltage range. People selling optimizers always seem to ignore this fact. The Tesla power wall has an MPPT range from 60-480 V DC. Anytime shading has the string above 60 Volts you will be getting all the power there is to get and expensive individual panel optimizers will not get you any more power.

[@GaryDoesSolar]

Optimisers will help with certain types of localised shading though (e.g. one or two panels shaded by leaves on a tree).

[@Candisa]

3-Phase connection -> 3 single phase string inverters instead of one 3-phase one. Disadvantages: slightly messier cabling, bulkier, slightly higher cost than a single 3-phase inverter Advantages: cheaper than micro-inverters or optimisers, soft shading on one panel only affects one of three strings, any failure within a string (incl. inverter) still only results in a loss of 33% production, overvoltage protection kicking in on one phase doesn't affect production on the other two, nothing but panels and cables on the roof. It's like having 3 huge panels with micro-inverters that are easily accessible.

[@GaryDoesSolar]

Interesting. Although, could the same effect be achieved with a single-phase string inverter managing 3 strings?

[@Candisa]

@@GaryDoesSolar A single multi-string inverter would also do the job shading-wise indeed. Downside is that a fault with the inverter itself means 0% production until the inverter is fixed/replaced, using multiple smaller string inverters is a middle ground between a single string inverter and micro-inverters when it comes to redundancy vs simplicity.

[@GaryDoesSolar]

@@Candisa Good points - I like your thinking! 😃👍

[@prakashs8536]

A tug of war between Microinverters and String with optimisers. Everyone is lying, not infact they are biased one or the other side. If cost and ROI is the concern, always go for legacy and proven. We need regulation in both sides to have some standards body to make sure customers do not suffer losses due to vendor lock-in as the solution is supposed to last half a century or more.

[@GaryDoesSolar]

Certainly, it's always worth putting in time and effort to check the performance and reliability of any product you're interested in before you part with your hard earned cash. Solar forums on social media is a great way to do this.

[@andyfeimsternfei8408]

One other consideration is that optimizers offer less current because of higher voltage, meaning smaller conductors for the same amount of power.

[@GaryDoesSolar]

What are you saying is the advantage of this though, Andy?

[@andyfeimsternfei8408]

@GaryDoesSolar With microinverters, you are collecting the power from each panel at 240vac. With optimizers, you are collecting the power from multiple panels at up to 400 vdc (600 max). So, for the same amount of power collected at 240v from microinverters versus 400v optimizers, the current will be lower with the optimizers, thus smaller or fewer conductors leaving the array. Granted, it doesn't make much difference on smaller arrays.

[@andyfeimsternfei8408]

@@GaryDoesSolar Plus optimizers' higher voltage DC home run could make a big difference if the array is a long distance from the load.

[@keyable]

Great explanation! +1 Sub

[@GaryDoesSolar]

Thanks you, and thank you! :-)

[@harryniedecken5321]

My con on micro inverters is that now you have ac and what people really want is dc going into storage for backup power. Selling to the grid isn't really that interesting.

[@GaryDoesSolar]

You can still have battery storage with a microinverter installation - it just has to be using an AC Coupled battery - see 3m26s into this video I made a few days ago: kzbin.info/www/bejne/rmmWpWSfeLKLrtk

[@chuongma3773]

Excellent

[@GaryDoesSolar]

Thank you!