Micro-inverters vs a single inverter

[rmk9785e]

I am being offered the choice between installing a single inverter (SolarEdge SE7600A-US) or micro-inverters (Enphase M215-60-2LL-S2x-IG-NA) with each panel (Kyocera Solar KU270-6MCA). I'm wondering which ones should I use. I'm thinking if a micro-inverter fails, there is more labor involved in going up the roof so it may be better to have one installed near my meter. I've also read elsewhere about optimizers and not sure how they fit in the picture.
Which one would you recommend and which brand is considered the most reliable?

[J.P.M.]

Unless you've got shading issues, many folks think a string inverter is the better option for the reasons you write of. String inverter systems are often a bit less $$ as well.

[rmk9785e]

I don't have any shading issues however the single Solaredge inverter configuration is about $2K more expensive than the one with Enphase micro-inverters.

[solarix]

I say that unless you have shading issues, putting electronics on your roof is a bad idea.
A regular string inverter (SMA, Fronius, ABB) is less expensive and much more serviceable.

[rmk9785e]

I say that unless you have shading issues, putting electronics on your roof is a bad idea.
A regular string inverter (SMA, Fronius, ABB) is less expensive and much more serviceable.

Thank you. That's what I'll narrow down to.

[ButchDeal]

I say that unless you have shading issues, putting electronics on your roof is a bad idea.
A regular string inverter (SMA, Fronius, ABB) is less expensive and much more serviceable.

That is not necisarily true. If you have to meet rapid shutdown then SolarEdge is generally cheaper than a string inverter.
It should be cheaper or at least same price as enphase as well but they are skimping on the micros with M215s on 270W modules.

[rmk9785e]

That is not necisarily true. If you have to meet rapid shutdown then SolarEdge is generally cheaper than a string inverter.
It should be cheaper or at least same price as enphase as well but they are skimping on the micros with M215s on 270W modules.

With my limited knowledge, I don't understand - are they proposing less than optimal micro-inverters?

[ButchDeal]

With my limited knowledge, I don't understand - are they proposing less than optimal micro-inverters?

The M215 is capable of 225w inverting and you have 270W modules. they are not going to put out 270W but will put out more than 225w quite often.
Thus there is power lost. The SolarEdge solution optimizers are capable of at least 300w.

[rmk9785e]

The M215 is capable of 225w inverting and you have 270W modules. they are not going to put out 270W but will put out more than 225w quite often.
Thus there is power lost. The SolarEdge solution optimizers are capable of at least 300w.

I see. The rated (continuous) output power of the M215 is only 215W which probably means that they won't even handle the 225W from the panel. It takes a lot of learning to understand what's going on. That's what we the consumers trust our vendors to have done for us.

[jflorey2]

rmk9785e[/B].;n326395]The rated (continuous) output power of the M215 is only 215W which probably means that they won't even handle the 225W from the panel. It takes a lot of learning to understand what's going on. That's what we the consumers trust our vendors to have done for us.

Around here (San Diego) I generally get about 80% of the rated output of the panel during "normal" (70F) days. That's 216 watts from a 270 watt panel. An Enphase M215 that limits at 225 watts output is actually accepting 233 watts due to its efficiency of about 96.5%. So your max input will be 223 watts, and you would usually expect to see about 216 watts.

LA? Phoenix? San Francisco? Florida? I wouldn't worry about it.
Denver? High desert in Arizona? Then you might see clipping more often (higher altitude, colder operating temps.)

If you are not having shading issues at all, you might also consider a "traditional" string inverter like the SMA line.

[jflorey2]

I see. The rated (continuous) output power of the M215 is only 215W which probably means that they won't even handle the 225W from the panel. It takes a lot of learning to understand what's going on. That's what we the consumers trust our vendors to have done for us.

Post didn't get approved, but to reprise quickly -

225 watts power out limit means 233 watts DC in. From my experience a 270 watt panel will put out about 80% of its rating, or 216 watts, on a 70F day. So if you live in an area like I do (San Diego) that's fairly moderate, you shouldn't have much of a problem with limiting. If you live in a high altitude/cold area (Denver CO or someplace like that) then you may see higher power percentages due to the altitude and the temperatures and thus see some limiting.

If you have no shading issues, also consider a traditional simple-string inverter like the SMA line.

[idnominal]

I see. The rated (continuous) output power of the M215 is only 215W which probably means that they won't even handle the 225W from the panel. It takes a lot of learning to understand what's going on. That's what we the consumers trust our vendors to have done for us.

How do the enphase "M"s compare to the S-230 / S-280s?

[ButchDeal]

96.5% efficiency for M to 97% for S. The S series is newer.

[ButchDeal]

...put out about 80% of its rating, or 216 watts, on a 70F day...
As others have mentioned, typically M215's limit at some power _above_ 215 watts, so that adds to your margins. So I'd expect to see little to no clipping depending on your conditions.

I love how when you mention clipping with enphase apologists come out of the woodwork with how it ain't so bad.
My point is it is there. you are paying a premium for premium parts and efficiency why would you deal with clipping.
We have systems all over the US, I monitor them and see the data. This is going to clip, particularly on cooler days with a breeze.
Not only that but as jflorey pointed out the efficiency of the M215 is just 96.5% The S series ( is a little better at 97%)

[J.P.M.]

[QUOTE=jflorey2;n326416]
In this case he is not talking about a traditional string inverter. It's talking about a SolarEdge solution (with optimizers at each panel) vs an Enphase solution (with microinverters at each panel.)


If you are not having shading issues at all, you might also consider a "traditional" string inverter like the SMA line. QUOTE]

My point - perhaps poorly stated - was that a standard (without optimizers or extra failure electronics exposed to the elements on a roof) string inverter such as you mention might be a better choice for the OP's application if shading is slight/non existent.

[silversaver]

I am being offered the choice between installing a single inverter (SolarEdge SE7600A-US) or micro-inverters (Enphase M215-60-2LL-S2x-IG-NA) with each panel (Kyocera Solar KU270-6MCA). I'm wondering which ones should I use. I'm thinking if a micro-inverter fails, there is more labor involved in going up the roof so it may be better to have one installed near my meter. I've also read elsewhere about optimizers and not sure how they fit in the picture.
Which one would you recommend and which brand is considered the most reliable?

SolarEdge optimizers, which has about the same failure points as micro inverters.

Keep it simple, period.