Micro-inverters VS DC Optimizers (Solar Inverter) 

Wow, thank you!

I guess im randomly asking but does someone know a method to log back into an instagram account?? I was stupid forgot the account password. I love any tips you can give me.

@Peter Reed instablaster =)

@Eduardo Payton i really appreciate your reply. I got to the site through google and im in the hacking process atm. Seems to take quite some time so I will get back to you later when my account password hopefully is recovered.

You really should either take down this video or put a disclaimer that the information on Shading is incorrect. The whole String Inverter discussion about shading having an impact has been busted by several people and companies using a Scientific approach. You make excellent video's but you are doing your customers a disservice by regurgitating false information without doing any research. Joe if you wanna know the Truth look at this video or search for some others, the proof is all over the place. ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-UQ9Szhl1ceQ.html

Thanks for the support!

Yes. another good point. The micro-inverter architecture is more easily expandable. I would also say that it is more economical for smaller systems by avoiding the large cost of a central inverter. I think SolarEdge offers 3,800W as the smallest option. For a small DIY, you might want to start out with only 1-1.5kW. That's much easier to do with micro-inverters without spending an arm and a leg.

Exactly what I did... Adding more panels is just so easy.

@@SolarSurge thanks Matt and Joe, this is one of my primary questions about solar. We live in the Sierra Nevada in California. Our electricity costs twice the national average, power company powerlines start many fires each year, and we are increasingly plagued by power outages. I'm out of my home today because the power has been out for a week because of fires.

Please wait for the year 3th - 5th.

Mark my words, micro inverters won't last 25 years and those systems will have more frequent breakdowns, simply because there are more Points of failure

Glad it was helpful and thanks for the support!

@@ts757arse Not so they match, but are the highest total string voltage. This improves the inverters conversion efficiency. See this white paper Figure 3: www.solaredge.com/sites/default/files/se_application_fixed_string_voltage.pdf In the optimizer, a DC-DC converter, there is no conversion to AC. That's done at the inverter. Nothing the user need worry about.

@@ts757arse in DC systems harmonics and phase angle cut-off do not exist. That happens in AC sytems when frequencies are present. Modern DC/AC inverters can modulate sine waves in a near perfect way, it is the load wich switches the AC current and cause higher harmonics.

Exactly ... this video as so many others takes the "one panel kills a whole string" as gospel without any actual testing. In most cases a simple diode or two is sufficient to deal with the problem, much cheaper and less prone to failure than either a microinveter or optimizer. One does lose the panel level monitoring though but is this worth the added cost ?

And don’t forget that with the Micro Inverters you have grid level voltage at all times from the fuse box all the way through the rooftop array to the last panel. The optimiser system only has the DC voltage on the roof but when it is not under load it reduces down to 1 Volt per optimiser which is so much more safer.

Any brands with shade management, and expandable string DC system that is not SolarEdge?

Yes the failure rate on central inverts is a lot lower, however the optimisers have about a 90% reliability and also suffer from heat like pannel level inverters . What no one is talking about though is mow we are seeing >500w pannels appear now it won’t be long before 72 full cell models appear for residential builds , enphase development team really have dropped the ball even with the iq8 design is limited on top models to 400w that may have been fine pre covid but time waits for no one as >500w panbels have been the goal for many home owners who have significant smaller panel’s in an area often limited to 16 even with real world losses it’s still far higher than enphase allow forcing owners it to old style strings

@@ram64man Maybe a dumb question because I'm new to solar. Are the >500w panels 72 cells? Or are there 60 cell ones getting to that point?

@@TheArtificiallyIntelligent there are 72 full cell _144 half cell models from jinkco solar and ja solar 540w. 570w on the market but supplies are very limited my contacts in india only got one shipment that's being used for water heaters in combination with water pumps in rural areas

Glad it was helpful!

Yes on all, except for car batteries. You don't want to use a car battery for deep cycling. Use lead acid golf cart batteries for off-grid solar.

Thanks for the reply. You are correct. Parallel branch cable length for the microinverters is close to the Solar Edge max string length.

Hi Lee. Thanks for the comment. That's the first I've heard of the RF interference issue with optimizers. I'm a ham also, KK4WPO.

Are you the type of operator who calls the FCC on your neighbor?

@Lee Stanley - microinverters directly connect to the AC grid and hence have to comply to EMC standards in order to be legal to be sold. With DC optimizers and a string inverter there is a legal grey area. The inverter must meet EMC standards as it connects to the AC grid, however it is OK to test it without any of the DC optimizers connected or if they are connected it is OK to conduct the test with the optimizers set in their inactive 'bypass' mode. Since the DC optimizers do not directly connect to the AC grid then they don't need to comply with any of the EMC standards. This is part of the reason why optimizers are lower cost as they can be built without any form of EMC filter.

@Michael Harrisson will this also affect cellphones and two-way radios? We're planning to expand the number of panels but would not want our weak cellphone and two-way radio performance to get worse.

@@paulburger2866 technically speaking the noise generated by optimizers can interfere with all forms of radio transmissions, however ham radio is a lot more susceptible than other forms of radio. Cellphones use digital modulation schemes which are really immune to background noise and deal well with most sources of noise. They can also adjust their transmission power to help get through background noise when they detect it. If your site is a long way from the cellphone tower and you have marginal reception (only one or two 'bars' of signal strength) then background noise can be the difference between being able to have cellphone service or not, however with a cellphone you are not so aware as a user as to the impact of background noise. With a ham radio operator you are more aware of any background noise and the impact that it is having on your ability to communicate.

Not that bad if the whole system goes down. The fact is all inverters, including micro inverters, will need to be replaced in about 20 to 30 years. With a string inverter you do it once and your done, with micro inverters you will have to replace them at different times. So if you have 20 panels you will have 20 different repairs at 20 different times. What a pain and the cost will be through the roof.

@@mikegardner8450 And with a 570W panel being 130 euro these days while the micro-inverter is above that, it might be more interesting to just add panels instead of inverters.

Unfortunately its not accurate information. The Truth about Shading: ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-UQ9Szhl1ceQ.html

@@Dreadlk Interesting. Think this is true for Tesla’s inverter?

@@gilbrook It's true for any modern panel. Only solar panels that are over 15 years old where effected by shading. Since then they have added in bypass diodes that reroute the power when a section of the panel gets shaded. The other problem that Joe does not mention is clipping. You will get more power out of a string Inverter system than Micro Inverter if you live in a sunny area like Ca, Fl, NV etc. It's only when you go further North that the Micro Inverters have a slight 3% advantage. In sunny locations Micro Inverter clipping will kill up to 15% of your power generation during peak hours. Please look it up on RU-vid and you can see more detailed info on clipping.

@@Dreadlk Understanding clipping is good. Best to drive inverter to highest rating. I’m looking at 4kW (twelve 340W panels) w/Tesla 3.8kW dual MPPT inverter. No shading between 9am and 3pm. Going to allocate 6 panels to each MPPT. Your thoughts?

@@gilbrook Sounds like a good plan, just make sure that 6 panels produces enough voltage for the Tesla. It should but I don't know the panel specs.

I believe installers should look for the best solution, not the cookie cutter one they prefer.

Thanks for the tip. In my experience, SolarEdge has had good response time and they are usually willing to send you a replacement inverter without much resistance. However, the higher failure rate and customer down time is still a problem. Enphase has been way more reliable since we switched over.

I’ve installed many thousands of solar panels with micro inverters. Less than five failed. (Not 5%)

Good points here. Both micro-inverter and optimizers allow you to mix and match different solar panels.

There are some considerations that need to be made as panels are getting larger some backwards compatibly will work but may require a single inverter upgrade FYI

Thanks. Please keep liking and sharing.

Agreed...he is clear, concise, honest and straight forward. He does a good job!

Hi JP, thanks for writing in. I'm not aware of any multi brain inverter like this. Most modern homes need AC power so an inverter is going be in the equation somewhere. I would suggest to use an efficient inverter and the most efficient lighting and appliances. That keeps the home wiring and maintenance simple since it would be using standard AC wiring and circuit breakers.

Hi Ryan. Thanks for writing in. Good point about the easy expandability of the micro-inverters. In order to provide off-grid backup power, we would pair the micro-inverter system with an AC battery like the Tesla Powerwall II or the Enphase Ensemble.

@@SolarSurge Do DC batteries like the Generac not work in an off grid scenario with micro inverters? Based on your other videos I would think the Pwrcell would be the logical choice for rural homes that need to start large loads off grid and micro inverters reduce failure points. Thank you for the high quality content. Looking forward to starting a quote.

@@Bombuzzz The Generac system uses a central inverter only (1 or 2) PWRCell X7602 inverters. There is no ability to mix and match micro-inverters with Generac's system.

That is an excellent point. But what I am not clear and need confirmed is if one panel is shaded or fails the rest of the panels still work and produce energy

Thanks! Will do!

Hi Vincent. You should be able to purchase SolarEdge P340 or P400 optimizers. Try renvu.com or Krannich Solar.

@@SolarSurge The P340 might be the better choice, because it would run closer to its best efficiency point, on my 72 cell 300 watt panels. (I need 54 of these!)

Single point of failure vs multiple points of redundancy? I think anyone would prefer the latter. If I were not limited by the cost I would've invested in DC optimizers myself.

@@shahzebatiq1 The point is how many panels/optimisers have to fail before it's worth the cost of paying for a scaffold and electrician to fix them? There's going to be a curved graph in it and typically you can bet that when you've decided to repair 5 panels/optimisers then another 3 will fail the day after the scaffold is gone.

With Solar Edge you get the worst of both worlds, Failure points on the roof as well as the central inverter.

@@westcoaststacker569 That's why I was dowering about whether the optimisers could be sited within the roof space itself so that replacement could be carried out if needed?

@@videogalore Their displays are shown that way, but the leads are short and designed to be installed under the panel. To install them elsewhere would require a pair of wire from each panel to the optimisers. This would also nullify the remote shutdown feature.

Hi Geoff and thanks for writing in. I'm glad to hear you've had such success with SolarEdge. In my personal experience, they are not reliable. Especially the HD Wave Set-App inverters. When they first came out we were seeing failure rates up to 50% right out of the box.

I agree, I feel like this review was a bit biased. I know a few people who have Solar edge with virtually no problems including myself.

@@fcodxdart1083 Here's a perfect example. I got a text message today from a friend who got solar installed 2 years ago using the SolarEdge HD Wave 11400 inverter. The inverter failed with error code 18xB5. SolarEdge says the unit needs to be replaced. The local contractor is charging $500 to do the repair, but SolarEdge is only reimbursing $225. That's the kind of BS you get with SolarEdge.

Solaredge 99% efficient enphase 95% (unless it overheats then it drops quite dramatically) biggest downside is its scalding hot underneath a black solar panel

yes anything there's an energy conversion you will lose energy. also cable thickness is a loss, to small to much resistance. but dc also drops fast over distance vs ac. then heat is a factor to.

Don't be serious about the Inverter Eff. but you should look at the loss from Panel low quality, direction of pv you install and even the degree of roof slope.

Good question. Both Enphase and SolarEdge allow you to add an AC-coupled battery in the future. However, I still favor Enphase for the scenario because of its ability to partition the PV array into multiple segments to avoid overloading the battery.

Hi Richard and thanks for writing in. In this case, I would recommend that you install enough battery storage for at least 50% of your average daily energy harvest. For a 14kW system, that would be roughly 3 Tesla Powerwalls or 4 Enphase IQ batteries.

That depends on what size solar panels you are using. As of today, the highest output Enphase micro-inverters are 349W AC. So for high-output solar panels like 400W+, I think SolarEdge has an advantage to minimize clipping loss.

@@SolarSurge Thank you Panels 360Wp 268W NOCT with IQ7+ microinveters Should be ok

How would you size the AC cable for the system? For each drop? Does it all meet at a single joining or combinig panel before the point of use or the feed back to the grid? Would that panel need any kind of 'intelligent' control?

​@@atlantajunglepythons1744 I have 3 "strings", a South, East and West on the roof. They all feed into the attic, where I have 3 isolators, one for each area. Then they join together and a single feed drops down inside the wall cavity to the fuse box where it passes through another isolator, a fuse and into the main fusebox. (I may have an excess of isolators but they reflect how my system has slowly grown! Adding panels is very easy). The microinverters have their own special cable string with plugs which you purchase, although it's only long enough to link the panels and you have to extend the tail to get some useful length, but at this point you're "just" handling mains AC. I use an outdoor rated junction box under one of the panels with waterproof glands to join it to an outdoor rated silicone flex which then passes into the attic and to the isolators. I sized the cables for the maximum theoretical current possible (so higher than will ever flow), and higher than the fuse. Being a Brit, I may have an easier life with this than in USA/Canada, I only have a single phase to worry about, and regular UK twin and earth (2.5mm) solid core is rated for 20amps when internal in a wall, that's 4Kw on cable I can buy in any electrical wholesaler. Feed in fuse is 16amps. The extended wiring from the micro inverter tails is also 2.5mm, but outdoor rated silicone flex, again capable of more than will ever pass, and in excess of the fuse. Controller, yes, I'm using Enphase gear, so there's an Enphase Envoy-S next to the fuse box with a current clamp on the grid feed and on the solar feed from the attic. The Envoy gives me all the stats (panel level) and also throttles the panels to prevent grid back-feed (the feed-in tariff here is pitiful, so I'm not giving it to them!). The Envoy will also handle the battery system if Enphase ever get their act together and make the battery system available for me here!

You can use either Enphase or SolarEdge for grid-tied solar with module-level monitoring. Then you can add a Sol-Ark via AC-coupling for your battery backup needs. Most professional installers won't offer this , buy you could do the Sol-Ark as a DIY add-on with the help of an electrician.

@@SolarSurge Thank you for the quick reply - and all your outstanding videos. I've learned a lot by watching these.

@@JeffMcNeal Glad it was helpful.

Yes, in theory, optimizers are better from DC battery systems. However, in my experience, the reliability of optimizer-based hybrid inverters (StorEdge) has been poor.

This is incorrect. Enphase on the roof with Encharge storage is 👑. Passive cooling, grid agnostic, etc.

No. The optimizers allow electricity to "leap frog" over a shaded or covered solar panel.