Solar Guppy wrote: »
And why Enphase can sell the inverters below cost, just like the Cell Phone company's
Got to give Enphase credit, the PR is convincing allot of posters to use the inverter when it has zero advantage to harvest. All the BS about partly shadowed arrays is a fix for a problem that shouldn't have PV panels installed in such locations in the first place. I guess PV has gotten big enough that its about shoveling product, not installing productive systems
On the comments on whether a company is having financial difficulty, who cares, either the panel works or it doesn't. If PV production follows other industry's, in 5-10 years all PV will be made in China, so comparing a company in Japan vs Germany is a useless point, they all can't compete to China.
Evergreen isn't going anywhere, The stock or bond holder may not be happy, but the company will have no issue with wiping out the stock or bonds holders and happily keep going
Solar Guppy wrote: »
The Enphase are 190 watt maximum ( or whats listed on the sponers site ), not a good match for a 230 watt panel
Solar Guppy wrote: »
Technically, the maximum power point on a PV panel is quite flat. What this means is you can have a string of panels with different tolerances and they all self adjust to the lower current, sound horrible as Enphase promotes but what is ( intentionally ) over looked is the panels that are operating at a slightly lower current are operating at a higher voltage so the still are harvesting very close to the name plate wattage.
As long as you have a single string, a 5% difference between the panels current will be offset almost entirely by the individual panels operating at above the vmp voltage and hence there is little if any loss and total harvest. A central inveter is superior in efficiency to the Enphase, 95-97% for the newest transformer-less units.
The raw cost in hardware of per module inverters is close to 2X the cost a central inverter, the monitoring is free ( central ) and your not subjecting the inverters to temperature cycling that is an impossibility that those inverters will last anywhere near the claims Enphase and others make. I'm a hardware engineer with close to 30 years of bring products to market, it defies everything I know and I call it as I see it, Its all savvy and slick marketing program to sell a product.
There is nothing except interconnections that can fail on a solar panel, and if need be can be field repaired. On a percentage basis, its probably in the sub hundredths of one percent having a panel failure, much more likely electronics are BOS stuff
As warranties, just based on what is likely to fail, you will be changing an inverter when you have 30-40 of them on a roof every few months for free long before you will ever see a solar panel fail. I makes absolutely no sense to be worried about panels and giving the new on the block inverter company a pass. Lets have this talk again in a few years ...
It becoming very obvious, installers are not technical enough to know the difference between these products or even if they solve a real problem and be able to challenge the manufactures on their claims, neither are the customers and the company that has the best things printed get the sales. Enphase is making claims for there inverters that defy the electronics parts contained in them are capable from a durability point, doesn't matter, they can sell a few million, have an IPO and later when things start failing they will just start a new LLC with the insiders laughing all the way to the bank. 20 year prepaid for data monitoring, what a scam:roll:
And with regards to who cares about a solar manufacturer's financial stability and it's ability to honor a long term warranty...I care. Since I'm putting my reputation and financial stability on the line when giving 5 - 10 year system warranties on an installation. A panel working today is immaterial to the concern about a panel having an issue 8 years down the line and there being no recourse because the manufacturer is no longer in business. Yes they make a quality product. Yes the likelihood of having an issue with the panel long term is very low. But that's also true of other manufacturers; ones in better financial shape. Evergreen may or may not survive, I don't know and neither do you. Is it really such a "rare" event for companies, even big companies, to go out of business?
solarvic wrote: »
So what good is a warranty if 1 panel in your string goes bad and you can,t replace it because that model went obsolete? Are you going to replace the whole string or just mismatch it with something as close as you can find? I have had that problem already when I wanted to get more panels of the same linage. S:Dlarvic
solartek wrote: »
One thing I (and my partners) have decided to do as a company is maintain a warranty reserve account specifically for funding the purchase a small inventory of any modules that we have installed, that are still under our warranty, and get discontinued. So far, we have not had to purchase any modules yet for this purpose. We will probably do the same for micro-inverters if the newer generations turn out to not be compatible with the ones we have installed so far.
Your question also points out one of the additional, possible advantages of a micro-inverter system The module's electrical characteristics don't have to match.
solartek wrote: »
We will just have to "agree" to disagree on the long term prospects of the Enphase micro-inverters. Only time will tell. I'm just surprised you believe the ambient temperature swing where the micro-inverters are typically installed (under the modules) is anywhere near 60-70C. I actually went out and did some spot temperature measurements on the first Enphase based array I installed here in Central Florida in August and I just didn't see that kind of ambient temperature change over the course of a very hot day in August. Granted it was just one (hot) summer day in Orlando.