enphase micro inverter, is it really better?

[pepper]

hi guys

I finally got to talk to a solar panel installer today, and wanted to know your thoughts on the enphase micro inverters ? he was telling me there 7-9% more efficent then the other inverters they have out???

are they worth the extra cost, and do they really make a panel more efficient?


thanks for shedding any light on this topic

[Sunking]

Micro inverters have niche applications where shading and/or mixed orientation become issue. Installers like them because of higher profit margins.

More efficient? No not really proving proper design using appropriate size conductors.

[Mike90250]

So, they are 7% better than a 96% efficient multi-killowatt inverter? That's some trick.

[russ]

@ Pepper - You received a full line of BS from the salesman. Either -

1) He has no idea what he is chattering about

2) He is lying to try to make a sale.

Either way that is not a person I would want to deal with. There are plenty of honest folks selling solar systems.

I suggest looking around for one that seems honest and then verify their 'facts' here if possible.

Russ

[Naptown]

Here we go again
They are not 7% more efficient than a string inverter. About on par with a string inverter for inverter efficiency.
The difference is in harvest. By shortening the DC cables, eliminating module mismatch so each module operates on it's own MPPT instead of the lowest common denominator in the string. Variations in soiling on modules, output etc is how these obtain a better harvest, not because they are more efficient. They are particularly good for arrays where different tilt and azimuth for portions are required along with a partial shading issue such as a telephone pole, antenna or something rather small throwing a shadow on part of one module or different modules during different times of the day may occur.
However they will generally cost more than a string inverter. You will have to weigh the additional cost vs projected additional harvest. If shading is not an issue at all I would say that 7% is high and 5% is more reasonable, higher if some of the shading or orientation factors come into play.

[Naptown]

@ Pepper - You received a full line of BS from the salesman. Either -

1) He has no idea what he is chattering about

2) He is lying to try to make a sale.

Either way that is not a person I would want to deal with. There are plenty of honest folks selling solar systems.

I suggest looking around for one that seems honest and then verify their 'facts' here if possible.

Russ

I take a serious issue with the statement above.
How can you extrapolate from a single comment from someone who is obviously not an expert that may or may not have understood what was being said or misquoted what was said and make a blanket judgment. Were you there?
This is what i happen to do for a living and have many systems out there using mostly micro inverters. And yes the harvest is higher in an unshaded situation and higher with shading orientation/tilt issues. I guess in your opinion that makes me a liar and a thief.
So was the salesman a liar? That information he quoted is directly from the manufacturer's spec's where they have tested their inverters side by side with string inverters to come up with those figures.

[russ]

I take a serious issue with the statement above.

It is up to the salesman to make it clear - not up to the customer to somehow automatically understand. Especially in an area where the customer probably has no knowledge.

If Enphase makes the greater claims then let them prove it - Been done in their own works they say?

In house testing is like polling - setup the parameters correctly and you can get many different and varying results. I consider in house testing to have ZERO value as far as the customer is concerned. That is the reason there are rating agencies.

If 3rd party testing by an official agency doesn't support the claim then it doesn't fly. If it does support the claim then there is no argument.

Sometimes wind turbine people use some independent lab for 3rd party tests - that also doesn't fly - meaningless.

The opinion of nearly all the 'electrical experts' that I follow is still that the single inverter is preferable. Installers seem to prefer the microinverter as it is an easier installation.

I have zero confidence in salesman - sorry. There are good and honest ones for sure. The one that potentially gets hurt is the customer if things don't work right while at worst the salesman only loses a sale.

[MarineLiner]

I take a serious issue with the statement above.
. . . . .
So was the salesman a liar? That information he quoted is directly from the manufacturer's spec's where they have tested their inverters side by side with string inverters to come up with those figures.

[russ]

A visit by a company salesperson is nice. Did you have someone knowledgeable about inverters present to ask questions. Or did you just accept what Lisa said as 100% correct?

The micro inverter may turn out to be the better choice but only time will tell. Enphase does not seem to be the only one on the market though they have the best PR department by far.

I read that even now Enphase is switching from the electrolytic capacitors in their next model due out soon. That addresses one potential problem many have mentioned.

I have signed purchase orders for a few billion dollars worth of equipment over the years in project management. I learned the hard way many years back that you never accept a salesman's story without your own research to check what is said.

The salesman may even believe 100% what they are saying but they have been given a false story.

Even the best of companies with long histories come up with some real doozies from time to time.

The marketing department often has the least technical expertise of any group in a company with the possible exception of the janitorial department.

[MarineLiner]

A visit by a company salesperson is nice. Did you have someone knowledgeable about inverters present to ask questions. Or did you just accept what Lisa said as 100% correct?
. . . . .
I read that even now Enphase is switching from the electrolytic capacitors in their next model due out soon. That addresses one potential problem many have mentioned.

I have signed purchase orders for a few billion dollars worth of equipment over the years in project management. I learned the hard way many years back that you never accept a salesman's story without your own research to check what is said.

The salesman may even believe 100% what they are saying but they have been given a false story.

Even the best of companies with long histories come up with some real doozies from time to time.

The marketing department often has the least technical expertise of any group in a company with the possible exception of the janitorial department.

[russ]

That is what the forum is - a place to discuss.

I was asking about the visit by 'Lisa' to your place - you said you were impressed.

The forum is not a place for sales pitches and or advertisements - you can do that on your own web site if you so chose.

The forum is a place to try to assist people who have questions or problems with solar. Rich has been great about that. The Enphase claims do not seem to be accepted by the larger community of 'electrical experts' as of yet.

Russ

[MarineLiner]

That is what the forum is - a place to discuss.

I was asking about the visit by 'Lisa' to your place - you said you were impressed.

[QUOTE=MarineLiner;22155]

[russ]

@ Marine Liner,

I am not even sure what you are trying to say.

I don't remember a company representative of a well known company requesting to post or posting. I do remember a lot of nobodies trying to drop links.

The attempts out of China by small parties have no use at all. Trying to collect on their warranties would be good for a laugh.

This is like discussing the Clarion plug and play unit that has been coming to the market for a couple of years now. If and when they get UL certification and meet NEC code they could be of interest. Unfortunately with their small size (wattage) I doubt they ever will do anything on the market - overpriced no matter what they do.

Russ

[MarineLiner]

@ Marine Liner,

I am not even sure what you are trying to say.

I don't remember a company representative of a well known company requesting to post or posting. I do remember a lot of nobodies trying to drop links.

The attempts out of China by small parties have no use at all. Trying to collect on their warranties would be good for a laugh.

[russ]

Same policy as always - if you want to you can PM anyone for your own use - providing they are not deleted first.

Russ