enphase micro inverter, is it really better?

[Naptown]

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

I think history has shown that there were similar sentiments regarding the new fangled horseless carriage.

We are just going to have to agree that we disagree. The debate is fun however!

[russ]

I am neither for or against either one. I don't know enough about the topic.

I think Enphase should support their claims of extra watts gained through a 3rd party though. Then there is no discussion - what is, is.

Their annual monitoring charge puts me off a bit. The way they enforce it by refusing access to 3rd parties is not too nice - reminds me of a software company.

What about other micro inverters - Enecsys and others?

[MarineLiner]

I am neither for or against either one. I don't know enough about the topic.

[russ]

We have about 4 guys - maybe 6 and one lady that have the expertise in electrics/electronics to say anything about the microinverters - only Rich has experience with the units. I mean many units - not 8 or 10 on one roof.

I read that Enphase is doing away with one of what is considered as a weak point by various parties at this time - the electrolytic capacitors.

The definition of moderate does not include standing back when someone gets on on a strange/silly line of thought or is trying to exploit a weakness.

Russ

[MarineLiner]

I think history has shown that there were similar sentiments regarding the new fangled horseless carriage.

We are just going to have to agree that we disagree. The debate is fun however!

[Vandergraaff]

Enphase "Backward Compatability"

I will likely be installing the enphase D380's for my 14 module roof array in a few weeks. A big part of my decision is based on the way the sun rises over trees in the AM, and sets over them in the PM (around 3 PM in the summer). I can watch the way the shadows sweep accross the roof and figure I can buy around 1/2 hour more of good sun each day this way.

I understand that there have been some reliability issues and that enphase has stood behind their product. However, time marches on and products continue to evolve. Assuming that enphase is still in business, will they be able to supply me a replacement inverter in 10 or 15 years? It doesn't appear that their new product is backward compatible, but are they making an effort to address this?

Should I buy a spare micro-inverter?

As my old boss put it, we get paid to worry.

Thanks,
Art

[russ]

Hi Art - You are correct - Worry about it now - later (after the purchase) there is no use in worrying as you will have what you have.

The actual question I will leave to Mike, Sunking and Rich - possibly others.

Russ

[Mike90250]

Buying a spare never hurts, if nothing else, it cuts down on the days/weeks for getting a replacement unit. Be sure to test it for a month or so, then swap it back, and store a known good one with a month of use.

Who knows what companys will be around in 3 years, let alone 14 years, but if they are still in business, they should still honor the warranty sold with the unit.

Be sure that you understand their warranty, they talk up the 15-25 years design life, but the warranty is shorter.

[mwild]

Microinverter advantage analysis

My impression, and I'm not an engineer, was that the main benefit of the microinverters was that the DC/AC conversion was right at the panel. Therefore, you eliminate the DC losses betweeen the panels and the inverter in a typical system. I wonder if someone knows how to calculate (or estimate) the DC losses. How much power do you actually lose per ft?

[Mike90250]

If the wires are sized properly, losses are less then 2%. They shine in situations where shade covers the roof, and instead of an entire array being knocked offline, only individual panels go off.

They aren't magic, if you get a blob of bird poo on a panel, it's shadow shuts down the PV material in the shade, which limits the current through the whole string. Enough shade, and the bypass diodes kick in, enableing a string inverter to operate at a lower voltage at full current, but an enphase inverter may just drop offline !

[Naptown]

I will likely be installing the enphase D380's for my 14 module roof array in a few weeks. A big part of my decision is based on the way the sun rises over trees in the AM, and sets over them in the PM (around 3 PM in the summer). I can watch the way the shadows sweep accross the roof and figure I can buy around 1/2 hour more of good sun each day this way.

I understand that there have been some reliability issues and that enphase has stood behind their product. However, time marches on and products continue to evolve. Assuming that enphase is still in business, will they be able to supply me a replacement inverter in 10 or 15 years? It doesn't appear that their new product is backward compatible, but are they making an effort to address this?



Should I buy a spare micro-inverter?

As my old boss put it, we get paid to worry.

Thanks,
Art

I would wait before I installed the M380's The M215 is coming out in a few weeks and seems to be a better inverter, completely redesigned Higher wattage, lower voltage tolerance and a 25 year warranty. I believe they also switched away from electrolytic capacitors but am not 100% sure.
There is some stuff on their website or I can post a link if you need it. I just got the product info announcement today.

[Vandergraaff]

The D380 will handle 2 modules, but it seems as though the M215 is only intended for 1.
I have to imagine that this translates into higher cost. Guess I'll have to contact enphase and find out first hand.

Thanks,
Art

[Naptown]

Actually no the 380 is twice the cost of the 190 and the 215 is comparable to the 190 price wise

[Vandergraaff]

Actually no the 380 is twice the cost of the 190 and the 215 is comparable to the 190 price wise

At the moment I see the 380 going for $335 and 190 for $214. About a 25% savings if I go with the D380 instead of 2 M190's.

Do you see better prices out there?
Where do you see prices for the M215?

Thanks for the help.

[Vandergraaff]

Now that I look more closely, the M215 and D380 are completely different animals. The M215 works with a 45V max input, while the D380 is made for 2 56V max inputs.

When considering these max voltages, I assume I need to add 25% to the module Voc (as per the NEC). This puts the M215 out of spec with the panels I'm considering.

I better give them a call....

Art