Sadly, and I state this because I really wish microinverters would achieve higher levels of quality, as up to date microinverters continue with its high failure rate.

Two things caught my attention:
1) Companies that sell both string inverters and Microinverters are not promoting microinverters. So I called a few support groups from those companies and their techs advise me to continue to use string inverters that meet the rapid shut down criteria. This pretty much discourages me to try them again on our customers installso weation.
2) Installers that are focused on commercial and high efficiency production guarantees are not using microinverters. Simply put, the efficiency, the cost and the output are not there.
So I did another search and came across this analysis from a serious university in Denmark:
Optimizers lose vs string inverters.
I was sad to see this , but now the time that you have to spend trying to get a support tech from Solaredge over the phone vs a tech From SMA makes sense. Its almost impossible to get someone to support you on optimizers in the after noon. You can always get someone from SMA on the phone.
Although the support from Solaredge is much better than two years ago, they are still far behind in response time and quality of service compared to SMA.

We really wish Enphase and Solaredge would improve their quality/Failure rate. The concept and ideal conditions make more sense than using string inverters. The problem is that using them in the real world applications and commercial installs is still not possible. They are still much more expensive than string inverters and their failure rate makes installers that use them mark up their price or charge labor to change them.

We seldom hire installers from competitors, but when we do we always hear the same story:
They still have to go back some weeks after every install to replace the initial fallout of microinverters.

2019…..A few years ago, I posted the following article about microinverters:
While microinverter companies still claim to have a better solution than string inverters, the USA is still one of the few countries that use them.
Kaco pulled out of the US market , knowing microinverters are not a good solution for rapid shutdown and power control. And believe me, Germans are practical.
While SMA (yes another German company) still prefers to add a Rapid Shut down system rather than to place any electronic equipment in the worst place possible, behind a solar panel.
In theory they remain loyal to their claim: You can monitor each single panel production by website. And its true! But a good installer knows better than install panels pointing west, east and north or doing installs that just wont work.
Sure, all companies will replace the microinverters that fail (which I have seen failure rates on the field of up to 30% in less than 5 years of usage). But they don’t disclose that the installer will charge to replace the inverter. And that’s is coming from the end user pocket.
Lets face it. The technology is still not there.
But hey, we still believe it will be there one day . And we support research.
We offer our customers no charge to replace a microinverter . BUT notice we wont recommend a microinverter system when a string inverter system can be used.
Interested in installing micro inverters? Do your homework and research how many countries besides the USA use them. You will see the impractical defeats any good theories.
I am all up for protecting our firefighters, but there are better methods of disconnecting solar arrays than micro inverters. And as for monitoring, in our company we offer guarantee of production. We dont let the customer worry about which panel produces and which one wont. Thats our job!.

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