Optimizer vs Micro Invertor Question

[insaneoctane]

I'm sure there are LOTS of debates on this topic, so let me narrow my question.
Regarding the DC optimizer vs micro-inverter debate, one of the pros to microinverters (IMO) is the removal of the central inverter, which I think most folks would agree is the shortest lived component in most solar arrays. But, in DC optimizer installations, you have BOTH a local component on the panel (most folks like to point out that this is "many points of failure" model) AND an expensive central inverter! It just seems like if you were going to gamble on a new technology, you'd at least get one that removes the $2k or $3k central inverter??

Am I missing something obvious?

[Mike90250]

Am I missing something obvious?

Yep. You are taking away the central inverter (shortest lived component) and replacing it with a dozen hard to access inverter boxes that alternately bake in the sun and chill each night. I'll keep my short lived inverter where it's handy to replace.
Word is now filtering out past enphase's "firewall" that they are having inverter failures and they are warrantying them now. couple more years, that may change.

Optimizers and micro inverters are problem solver gadgets. If you don't have an issue where you must install panels that will be shaded, they are the fix for that. otherwise, stick with a central inverter.

[insaneoctane]

Yep. You are taking away the central inverter (shortest lived component) and replacing it with a dozen hard to access inverter boxes that alternately bake in the sun and chill each night. I'll keep my short lived inverter where it's handy to replace.
Word is now filtering out past enphase's "firewall" that they are having inverter failures and they are warrantying them now. couple more years, that may change.

Optimizers and micro inverters are problem solver gadgets. If you don't have an issue where you must install panels that will be shaded, they are the fix for that. otherwise, stick with a central inverter.

Without a doubt, the central inverter is easiest to replace. Data and warranties show you should expect to do so after 10 years or so. Don't the micro inverters and DC power optimizers have a 25-year warranty? Agreed they will require more work to replace, but between years 10 and 20, you have the cost of an inverter (say $2k to $3k for 6kW), of "savings" to pay some labor to have those micro inverters replaced under warranty? Then from years 20 to 25 you have another 1/2 the cost of an inverter to apply to this same scenario. Clearly, micro inverters don't have long term data on their side, I'm just saying that you can't change the technology/equipment/industry if you aren't willing to change anything...

Also, I personally see value in panel-level performance and diagnostics that micro-inverters offer. Let the flames begin....

[Mike90250]

i'd much rather hoist a 80# inverter onto the wall, than pick 6 year weathered panels off a roof to get to the dud inverter.

Just because they slap a sticker with 20+ years on it, does not mean you will get 20 years on EVERY uInverter, just a free one after you justify that THEIR part broke, and that you didn't expose it to weather or some weasel word in the fine print. A $20 hr laborer is not likely to take good care of your roof and cables.

Any decent GT inverter can give detailed power data, but not for individual panels in it's string. you have to chart and suss that yourself

[russ]

Also, I personally see value in panel-level performance and diagnostics that micro-inverters offer. Let the flames begin....

Really only to the extent you can have a "solar party" where you show your and they show theirs.

[insaneoctane]

Really only to the extent you can have a "solar party" where you show your and they show theirs.

You don't see any value in being able to pinpoint where a 3% or 5% or 7% or x% problem is coming from? I will agree that if the system is working splendidly, you don't need the data. If it is not, it seems like great data to have.

I admit that I am a solar newbie... does someone want to share what kind of info your central inverter will, in fact, tell you?

[Volusiano]

Regarding the DC optimizer vs micro-inverter debate, one of the pros to microinverters (IMO) is the removal of the central inverter, which I think most folks would agree is the shortest lived component in most solar arrays. But, in DC optimizer installations, you have BOTH a local component on the panel (most folks like to point out that this is "many points of failure" model) AND an expensive central inverter! It just seems like if you were going to gamble on a new technology, you'd at least get one that removes the $2k or $3k central inverter??

If you think that the central inverter is short lived, why do you think the microinverter can last longer? Just because the warranty says so? Before you're ready to lap up microinverter's 25-year warranty, why don't you ask Enphase why they no longer include labor in their warranty? Sure, part is cheap to replace, but labor up on the roof 2 times, once to retrieve, another to replace, is where the money is. What is Enphase hiding by not including labor in their warranty? Isn't it because they don't trust that their microinverters will last the 25 years they warranty them to be? If not that, then why else?

Both microinverters and central inverters use the same electronic components to do the same function. One is miniaturized for 1 panel while the other is a larger scale design for multiple panels, but yet they use the same components for the same function nevertheless. One is down on the ground, most likely in the cool shade, while the other is up on the hot roof baking day in day out in the summer time. Which one do you think has a better chance of lasting longer?

And why you said, did SolarEdge do the dumb thing and still use the expensive and short-lived central inverter on the ground if they already have optimizers up on the roof? Maybe because did you ever consider that it's not a dumb thing to do, but a smart thing to instead? Maybe because they KNOW that putting microinverters on the roof is a bad idea, and that using central inverter is a better idea. The real problem that needs solving (if there's shading issue) is to localize the optimizer. Localizing the inverter is NEVER a problem that needs to be solved in the first place. Localizing the inverter is instead an asking-for-trouble problem in itself.

By the way, SolarEdge include labor in their inverter warranty, and also in their optimizer warranty.

By the way, central inverter companies include labor in their inverter warranty.

By the way, why doesn't Enphase include labor in their microinverter warranty again?

[Volusiano]

You don't see any value in being able to pinpoint where a 3% or 5% or 7% or x% problem is coming from? I will agree that if the system is working splendidly, you don't need the data. If it is not, it seems like great data to have.

I admit that I am a solar newbie... does someone want to share what kind of info your central inverter will, in fact, tell you?

With central inverter, if there's a performance problem with a panel, it'll manifest itself by showing a performance problem on a whole string itself. OK, so with microinverters, you can tell exactly which panel is a problem panel before you have to go up on the roof to do repair or replacement. With central inverters, you won't know which panel on the problem string has the problem until you go up on the roof and do debug. But so what? What's the big deal? The bad panel will still be found either way in the end, and replaced.

Panels rarely ever go bad, and if they do, most likely it'll happen before the warranty expires. So from the homeowner's point of view, problem detected, warranty call made, service call is made and bad panel repaired in the end. So why would a homeowner care to be able to pinpoint up front which panel is bad? That ability is over rated.

99% of the time, you don't care about the data anyway. You may fuss over it the first few months, then afterward it becomes stale and gets forgotten because panels rarely ever go bad.

[kellycross]

Panels are not good.

[sdold]

Panels are not good.

I'd watch this fellow, something isn't right.

[inetdog]

I'd watch this fellow, something isn't right.

Thanks for the advice. He could just be very terse. Or maybe just working his way up to ten posts for PM access.

[Jeepman]

With central inverter, if there's a performance problem with a panel, it'll manifest itself by showing a performance problem on a whole string itself. OK, so with microinverters, you can tell exactly which panel is a problem panel before you have to go up on the roof to do repair or replacement. With central inverters, you won't know which panel on the problem string has the problem until you go up on the roof and do debug.

Wrong... SolarEdge Optimizers (25 year warrenty) show each panel output and allow one panel to be shaded without dropping the whole string. On their monitoring site you can see each panel and watts/voltage/amps etc for each panel also. SolarEdge inverters are way smarter than just a inverter. Solar Edge inverters come with a 10 year warrenty that is extendable to 25 years for around $500.
Also your SolarEdge inverter will be compatible with Tesla Powerwall...if your are thinking that route in the future.

[ButchDeal]

Solar Edge inverters come with a 10 year warrenty that is extendable to 25 years for around $500.

They come with a 12 year warrant which is extendable to 20 or 25 years. Price varies based on size of inverter and years extended.

[Jeepman]

They come with a 12 year warrant which is extendable to 20 or 25 years. Price varies based on size of inverter and years extended.

Sorry...my bad. Lol With the new HD inverter I will probably not opt for spending money on the extended warranty and would just upgrade instead. I've had my system since July, 12 years is a long time...then again, 25 years looks good too.

[Yaryman]

Both microinverters and central inverters use the same electronic components to do the same function. One is miniaturized for 1 panel while the other is a larger
scale design for multiple panels, but yet they use the same components for the same function nevertheless. One is down on the ground, most likely in the cool shade, while the other is up
on the hot roof baking day in day out in the summer time. Which one do you think has a better chance of lasting longer?

By the way, why doesn't Enphase include labor in their microinverter warranty again?

My Enphase micro inverters are on the roof under each panel. No sun strikes them unless the sun is almost at the horizon. ( rising or setting )
My panels are on the south side of my house as is the main panel. That main panel and single inverter had I gone that route sit in the sun all friggen day.
Using the heat and sun make all the difference logic, I should have gone with micro inverters as they sit in the shade.

I understand the math of having 18 micro inverters vs one inverter might increase the chance of failure for my system.
There is also a certain logic of having 1/18 of my system fail vs the entire system failing.

Were that failure past the warranty of the single inverter system, I would be paying a large chunk of change to fix it.
Were the failure on one of 18 single micro inverters, it might make better financial sense to no bother fixing it.

As for the question about why Enphase stopped paying for labor on their warranty.
My honest answer is it's pretty hard to pay an installer $100 - $200 -$300 to replace an item the costs the installer $100 or so.
Maybe paying for the repair labor was a way for Enphase to gain market share.
That paying for the labor then bit them in the arse when there were more than expected problems with the M190 model.
Hopefully they figured out the problem, and the failure rate of the newer models is much lower.
Do a search for failures of the Enpahse M250. I wasn't able to find any horror stories.

Here is an interesting read as to why this company doesn't sell the Enphase M250