<html><head><style type="text/css"><!-- DIV {margin:0px;} --></style></head><body><div style="font-family:arial,helvetica,sans-serif;font-size:12pt">Hi Ryan:<br> I don't want to take your money, but I am sure I could, if I had the time to waste. I have issues with Enphase, too, and I am very aware of the drawbacks, but they are not nearly as extreme as you make them sound.<br> You did not even mention the #1 reason to use Enphase, however, which is the awesome monitoring ability. This is the clear reason to utilize Enphase. I have replaced more than 50 bad modules in the last couple of years, and I bet there are a ton more out there that we haven't found. I was at a site yesterday which had BP modules, and three of the modules had failed on one 36 module system. Micro-inverters could have saved a ton of troubleshooting time. On this job, we had to uninstall dozens of modules, test
them, and re-install the modules, adding up to more than 10 hours of labor. At $90 per hour, that is $900 that would have been saved by this one customer. Plus, the failed modules would have been discovered much earlier, and would not have caused multiple strings to fail!!!!!!! What a waste. Enphase eliminates this.<br>- I have installed thousands of Enphase inverters, and have only seen one failure. Only one. They are far more reliable than string inverters<br>- The wiring included with the Enphase wiring harnesses is too small, so I break each circuit into two sub-circuits, so this adds a $50 cable, which is necessary, but manageable, IMHO.<br>- They are more expensive, and listed at .5% lower efficiency than some string inverters, but higher than others.<br>- It can be difficult to maintain a 1.5% voltage drop on the AC side, but there is almost no DC drop, which is a plus that makes up for the lower
efficiency.<br><br><div> </div>Nick Soleil<br>Project Manager<br>Advanced Alternative Energy Solutions, LLC<br>PO Box 657<br>Petaluma, CA 94953<br>Cell: 707-321-2937<br>Office: 707-789-9537<br>Fax: 707-769-9037<div><br></div><div style="font-family: arial,helvetica,sans-serif; font-size: 12pt;"><br><div style="font-family: arial,helvetica,sans-serif; font-size: 10pt;"><font face="Tahoma" size="2"><hr size="1"><b><span style="font-weight: bold;">From:</span></b> Ryan LeBlanc <ryan@naturalenergyworks.com><br><b><span style="font-weight: bold;">To:</span></b> re-wrenches@lists.re-wrenches.org<br><b><span style="font-weight: bold;">Sent:</span></b> Tue, August 31, 2010 9:47:34 PM<br><b><span style="font-weight: bold;">Subject:</span></b> [RE-wrenches] Micro-Inverter Vs Central Inverters $150 Design Challenge<br></font><br>
Ok just got off the phone with a former student, now a designer at a<br>significant module manufacturer and I've almost hit my limit discussing<br>this, which now I'll make worse I'm sure. <br><br>... I can't believe that Enphase has received as much attention as they<br>have. <br><br>In my humble opinion, I'm asked way too much about this relatively<br>insignificant industry product. I wish I never discussed the ups and downs<br>of micro-inverters with Raghu and Martin before Enphase was Enphase. <br><br>Too many downsides to list, there are few niche applications that they can<br>work well within. Small residential is absolutely as far as it goes. Large<br>scale, no way. Their marketing department deserves the MVP for the company,<br>and the psychology of regular people and mostly solar newbie's today, plays<br>right into the "New & Shiny" toy thing. We all know conductor runs benefit<br>from higher voltages, at lower voltages for the
same power, systems require<br>larger more expensive conductors, overcurrent protection devices, Yadda<br>Yadda Yadda. <br><br>They are not less expensive.<br>They are not easier to design with. <br>They are not more reliable. <br>The proof will surely come out.<br><br>Don't be afraid of string inverters, you can do very short strings, and<br>don't choose to go with the bite size, but still un-satisfying experience of<br>working with them.<br><br>OK, yes, it may be true that, central inverters are no more reliable than<br>micro-inverters, by the same logic micro-inverters are no more reliable than<br>central inverters. There will always be a small percentage of bad units, a<br>known reality of electronics. <br><br>So I ask, as you are installing these inverters, do you know if they are<br>good until you have installed the modules, plugged them in and run them? I<br>know I don't, in which case I don't know if I'm burying 1,2,5,10,20,
etc of<br>bad units under the modules... in which case, you have to remove the<br>modules, often involving a lot of labor on the roof, requiring getting the<br>harnesses back on, setting up the ladder, replacing the "one-time-only"<br>WEEBS (if you use them) or undoing the equipment ground, cutting and<br>re-bundling wires and zip-ties, etc, etc. <br><br>The reason they won't be able to get much cheaper will be because of quality<br>control and testing each one extensively before leaving the factory, and<br>support, service and warranty response teams will be busy, busy. <br><br>If there's a project bigger than one string of 3 typical cSi modules,<br>shortest length I know the Sunny Boy 700U can work on, and you believe<br>Enphase is required due to shading or whatever, then A.) You probably<br>shouldn't be installing PV there, or B) You may need to learn about the<br>existing options and brush up on some other design techniques. <br><br>A good
question recently asked about performance is, "Are the claims of<br>shading performance gains that Enphase provides only good for panels that<br>don't have any bi-pass diodes or just one diode?" - I'm not sure and haven't<br>looked at their literature in a while, nor do I care to, so I would<br>appreciate an education on this one.<br><br>All I know is that customers don't like to see me back too many times, and I<br>know I've had to replace the same inverter a few times... with micro, it's<br>multiplied. <br><br>The beauty of central is that it doesn't take much, if any work on the roof,<br>to trade out a Xantrex for an SMA, Fronius, or whoever, but say you get to a<br>point where you do want out of the Enphase family... you'll have to<br>reinstall every single module... I'm nervous for the cool-aid drinkers.<br><br>Oh, and as for the future, ACPV... none for me thanks either... not for a<br>professional, for similar reasons mentioned above, and
not for homeowners.<br>We really don't need a homeowner installing their own ELECTRICAL systems.<br>This can only fuel the counter argument to solar with a likely exacerbated<br>blanket statement of solar being a dangerous fire-hazard on rooftops.<br><br>Here's a challenge, I will pay someone $150 dollars (same as Enphase<br>inverter replacement reimbursement) to show me a project designed using<br>them, greater than three modules, that I can't redesign using something<br>else, with equal or better cost, time or performance results. Seriously,<br>send me an old or new Enphase design, I'll look it over, and propose an<br>alternative. If a reasonable person won't agree in that alternative, I will<br>send a check.<br><br><br>Ryan J. LeBlanc<br>NABCEPT Certified Solar PV Installer<br>Cell: 707.591.1950<br>Direct: 707.536.9839<br><a ymailto="mailto:ryan@NaturalEnergyWorks.com"
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