Solarpro wrote:The SolarEdge inverter and power optimizer combination is a much better buy than micro inverters when it comes to performance and reliability. First of all the Enphase M215 micro inverter is only rated for 215 watts maximum, so even though a typical 250 watt solar panel with a +5% tolerance rating is capable of outputting 5% more than 250 watts you will only get a maximum of 215 watts out from each Enphase inverter.
215W is guaranteed, but they limit at 225W. See my previous post earlier in this thread.
Solarpro wrote:With an average of twenty micro inverters in a typical system, this will be a tremendous loss of power over the life of your system.
I assume you mean energy rather than power since you say "over the life of your system". In any case, this is a red herring. In reality, you will likely lose less than about 0.5% of your energy production due to this power limit with a 250W panel, less in a warmer climate like CA. That is not a "tremendous loss" in my book.
Solarpro wrote:With a system using SolarEdge power optimizers instead of micro inverters you will have a much greater maximum output rating of 300 watts.
Second, the Enphase 215 is only rated for 96.3 maximum efficiency and a CEC weighted efficiency of 96%. SolarEdge offers a considerably higher peak efficiency rating of 98.3% and a CEC weighted efficiency of 97.5%. This may not seem like a big difference but when you consider the 30 to 40 years life expectancy of your solar panels, the difference in efficiency will add up to considerable amount of power.
O.K., it seems efficiency is 1.5% higher. So perhaps 2% better energy harvest when combined with the higher power limit. That's good!
Solarpro wrote:Third, the Enphase 215 will only turn on when your shaded panels have reached 22 volts whereas a SolarEdge equipped solar panel will begin producing power with as little as 5 volts which yields better shade protection and better early morning, late afternoon energy harvest.
Sorry, I don't see this as something that would make a difference in most installations.
Solarpro wrote:Fourth, with Enphase, the portal which allows you to connect to the Internet so that you can monitor your solar panel’s individual performance is optional and costs about $500.00 whereas with Solaredge the Internet portal is built in at no additional cost. Also with Enphase you have to purchase their expensive proprietary cabling which costs about $40.00 per inverter. With SolarEdge the cabling is built in at no additional cost.
Total system cost is what matters. Which has a lower lifetime cost?
Solarpro wrote:We’ve been operating a factory authorized inverter repair center for the past 11 years and a common failure that we see involves electrolytic capacitors. Electrolytic capacitors use a semi liquid paste in their design. As electrolytics age, this paste tends to dry out and introduce ripple current into the inverter’s circuitry leading to failure. The hotter the environment, the higher the risk of electrolytic capacitor failure.
Agreed. As discussed previously, SolarEdge central inverters almost certainly have electrolytic capacitors in them and there are indications that M215 microinverters do not (otherwise they would have the same 15-year life limit that the M190s have). This may be a plus for Enphase.
Solarpro wrote:Enphase is one of the few micro inverter companies that still use electrolytic capacitors in their design (yes, the M-215 still uses electrolytics).
Source, please. We have discussed this extensively and we have not been able to find a credible source, only one person who stated that they have moved the 120-Hz filter capacitor from the input to after an initial boost converter, allowing the energy storage to be done with a film capacitor in the M215. Do you have a better source for your assertion?
Solarpro wrote: Micro inverters are typically mounted under the solar panel on a hot roof which makes many in the industry question the life expectancy of micro inverters that use electrolytics. The problem is that even though you have a 25 year warranty, that warranty will not pay for the labor of removing and replacing micro inverters as they fail. SolarEdge converters do not use any electrolytics in their design and they use far less heat generating components which increases their life expectancy. SolarEdge does not use electrolytic capacitors in their under module mounted power optimizers.
An important point to remember is that micro inverters may offer a 25 year warranty but that warranty does not cover the labor costs for removing and replacing failed micro inverters. It is an inescapable fact that all inverters will eventually fail. Unfortunately they won’t all fail at the same time. You may have some micro inverters that will fail at year 11 after your installation warranty expires and a few more may fail at year 13 and a few more at year 16 and and so on.
The same discussion applies to the SolarEdge units, plus they have a central inverter that can also fail.
Solarpro wrote:None of the labor costs for these potential failures after year 10 will be covered by your warranty. And you can expect the cost for an electrician to climb up on to you roof and remove and replace failed micro inverters to be in the neighborhood of $300 to $500 per site visit.
As mentioned above, both have module-mounted equipment. The only thing that really matters is the relative reliability and relative lifespans.
Solarpro wrote:SolarEdge recently announced that they now have over two million of their power optimizers installed worldwide and was recently awarded Intersolar’s prestigious 2012 innovation award in Munich, Germany.
That's good. How many Enphase microinverters have been installed?
Solarpro wrote:We have been selling SolarEdge as long as we’ve been selling Enphase and have had no SolarEdge failures to date whereas we have experienced multiple Enphase failures.
That's good information. How many years have you been selling them? What is the current MTBF for your Enphase installations? How many failure-free module-years do you have on the SolarEdge units? I am tracking Enphase microinverters and we have an ongoing discussion in this thread
. Feel free to join in there with additional data. I would be interested to see third-party public MTBF tracking of SolarEdge MTBF for comparison's sake. FWIW, NO failures of Enphase M215 microinverters have yet been observed. However, there are several systems with multiple failures of Enphase M190 microinverters. These few systems greatly lower the observed MTBF. It is not clear why the failures are grouped by system. I suspect it is either bad manufacturing batches, poor installations, lightning or some combination of the three.