Enphase Energy Micro-Inverter

[Mike90250]

Emphase requires one solar panel and one Emphase inverter. Common sense dictates Emphase is more reliable.

Statistics lie.

Unless Enphase has OUTSTANDING QA, and beyond space age technology, I don't see how they can state "Mean Time Between Failure (MTBF) of 331 years". ( 2,899,560 hours)

http://www.enphaseenergy.com/products/products/micro-inverter.cfm

( oh, wait, they say "someone else said it" )

http://www.enphaseenergy.com/downloads/Enphase_WhitePaper_Reliability_of_Enphase_Micro-inverters.pdf

MTBF is obtained by the sum of all the individual internal components, and then wrapped around the final product.


So if they sell 331 inverters, ONE will fail each year.

They do have a 15 year warranty, which is pretty good, if you can meet the requirements.

http://www.enphaseenergy.com/support/enphaseentrust/warranty.cfm

[Aussie Bob]

Inverters are a good subject. First let me say this. If you take a whole bunch of solar panels and connect them to one inverter it works until the one and only inverter fails. These type of inverters are analog in nature. Emphase requires one solar panel and one Emphase inverter. Common sense dictates Emphase is more reliable. If a Emphase inverter fails you loose a little power. The single inverter fails and the whole system is down. Now for another fact. Emphase is a digital inverter. They apear to be very robust in design and performance. It is up to you. I will be talking to Emphase soon and then I can answer more of your questions.

That's a good point, not having a single point of failure, ie - one inverter.

But back to costs, is it cheaper to use the mini inverters per panel, or go with the one main inverter? Has someone crunched the numbers? I do like the instant expandability of the panels with the built in mini inverters, without the need to have a big inverter sitting there waiting to be fully utilized.

[gogreensolar.com]

How do the costs compare, for say a 2Kw system with the micro-inverters in the panels, compared to a 2Kw system with one 2200w inverter?

The cost per watt for a complete solar grid tie system with enphase m190 inverters would be greater than a solar complete grid system with a central inverter.

although when comparing enphase inverters vs central inverters, you have to realize enphase is not simply inverter that turns dc into ac but an "inverter solution" which comes with the ability to monitor your system's performance through the internet, increased system reliability and saftey since the high voltage DC is being converted to AC right at the module level. Simplicity of installation since mirco-inverters are connected in branch circuits versus having to deal with the complicated process of string sizing.

so do you think value enphase inverters bring to the table are worth the extra dollars?

[MarineLiner]

Cost with enphase m190 inverters would be greater

The cost per watt for a complete solar grid tie system with enphase m190 inverters would be greater than a solar complete grid system with a central inverter.
.....
so do you think value enphase inverters bring to the table are worth the extra dollars?

[Mike90250]

an "inverter solution" which comes with the ability to monitor your system's performance through the internet,

And there is a yearly subscription fee for the monitoring.

There are good points for both systems, lots of redundancy with micro inverters, but as to complexity, over 2 KW, I think the Single inverter solutions are better, with much less complex wiring, simple DC string to inverter, AC to panel. Micros have DC to inverter (1-4 panels) and then daisy chain AC to a sub panel and then to the main panel.

I'm not sure how they get away with not having a DC disconnect, if there is a daytime fire, the F.D. wants to be able to kill power sources. They'd have to pull the main breaker, and trust the modules all shut down properly (except the smoking one).

I suppose time will tell what works and what does not.

[Aussie Bob]

The cost per watt for a complete solar grid tie system with enphase m190 inverters would be greater than a solar complete grid system with a central inverter.

Yeah, I figured it would cost more.

although when comparing enphase inverters vs central inverters, you have to realize enphase is not simply inverter that turns dc into ac but an "inverter solution" which comes with the ability to monitor your system's performance through the internet, increased system reliability and saftey since the high voltage DC is being converted to AC right at the module level. Simplicity of installation since mirco-inverters are connected in branch circuits versus having to deal with the complicated process of string sizing.

They're benefits, no doubt.

so do you think value enphase inverters bring to the table are worth the extra dollars?

For me, as a consumer, it would depend on what that cost difference is, as to whether I would see the benefits of these micro inverters being something worthwhile.

Great website you have too.

[EdgarNewt]

Any update to this thread?

I just sat in on a Akeena presentation yesterday and the panels they were showing incorporated Enphase micro-inverters. I like the Enphase micro-inverter, but I was less sold on the Akeena folks. Current thinking is that I might try and find an installer that will pair Sanyo 200s with Enphase micro-inverters for my installation. I would love to know if people have installed Enphase and if there is any additional feedback since June.

[Jason]

Hi Edgar,

Thanks for joining Solar Panel Talk.

Here is a quote from a recent post a member made about the enphase inverters:

"I just did a 3.3KW system with enphase inverters. They are very cool. A little harder to install than a conventional inverter because you have to ground the inverters and run the AC wiring along the rail. It just makes a bit more work trying to keep the wiring clean. There is some offset since you don't have to mount a big inverter on the wall but the enphase is definitely a bit more work. The cost of the enphase is not a lot more than a typical inverter. The monitoring is sweet and their customer service is awesome. But they are behind in production. We had to wait 3 months to get 25 inverters 15 for the 3.3KW and 10 for a 2KW that we haven't installed yet. Due to their lag time we just got the inverters when we could and are hiding them for this 2KW customer. Three months isnt too bad though. They told us when we ordered it would be 3 months and they came through exactly three months later. If you want their inverters and monitoring its worth waiting 3 months to get what you want."

by JustinSolarGuy

http://solarpaneltalk.com/showthread.php?p=2861#post2861

So I wonder if companies will start shipping their panels with a micro-inverter already attached? That would save on installation time and cost. It would most likely be cheaper to ship as well, rather than having it all shipped separately. Are these enphase inverters real heavy?

What area are you in Edgar?

[slade1977]

Jason,

I know it's something I'm looking at integrating on my solar panels once I get everything up and running. I'm about a year or so away from ironing out commercial viability of my panels (gotta love the UL process...I really wish one of the other testing labs would do equivalent testing to 1703 already).

My only concern is cost per panel. I haven't done much digging on price, but they seem to run around $200 a piece retail (not sure about what the wholesale/manufacturer's price is just yet). Even with the increased efficiency, I am looking at a much higher retail price then my chinese competitors without the micro inverters. I am still working on marketing the panels in a 'vanilla' form without them. In about 6 months or so, I do plan to extend my market research to include the micro inverters as an option, and gauge the interest from local installers.

I think it has great potential. Despite the wiring headaches, it does increase the efficiency, but not enough to equal the cost. Of course, once you look at overall system costs, it becomes more competitive. Personally, I like them because it keeps open the possibility of custom built modules that can vary in sizes across the entire system.

[EdgarNewt]

I am in Los Angeles. Andalay's new panels (175s) come either with or without the Enphase attached. Akeena is installing them in California (and I think acting as a distributor elsewhere). I wasn't planning on using Akeena as an installer or Andalay panels as I wanted a smaller footprint (using Sanyo or SunPower 200/200+ panels), but I liked the idea of a plug-n-play approach with Enphase built in.

The 3 month wait on Enphase doesn't sound wonderful.

I am also right on the bubble for solar as my summer electricity cost is around $45-50/month (no AC) and will likely be approximately $60/month in the winter. I am likely looking at a 2 to 2.5KW install.

[Jason]

I am in Los Angeles. Andalay's new panels (175s) come either with or without the Enphase attached. Akeena is installing them in California (and I think acting as a distributor elsewhere). I wasn't planning on using Akeena as an installer or Andalay panels as I wanted a smaller footprint (using Sanyo or SunPower 200/200+ panels), but I liked the idea of a plug-n-play approach with Enphase built in.

The 3 month wait on Enphase doesn't sound wonderful.

I am also right on the bubble for solar as my summer electricity cost is around $45-50/month (no AC) and will likely be approximately $60/month in the winter. I am likely looking at a 2 to 2.5KW install.

I'll get Justin in this thread, he's an installer in your general area that could give you some input.

[EdgarNewt]

I received a proposal for a 2.45KW install that uses Enphase inverters. Came in about $2k higher than I thought it would. Still thinking about it.

[varnuke]

My Enphase installation - 80 Sharp panels - 40 Enphase D380 inverters

My wife and I decided to install a solar system back in 2011. Did a lot of reading about the different types of components out there prior to taking steps to have one installed. Went to the "approved list" of installers here in Ohio and decided upon one from out of Cincinnati. BIG MISTAKE! Yes the guy was a master electrician, but he knew nothing about the engineering involved with respect to the increased dead weight on the roof and how that would affect the overall loading on the roof trusses with the addition of live weight in the winter months. But that was just the beginning. He also had no knowledge about the use of stainless steel (SS) fasteners and how using a high-speed drill to run nuts down on SS threads could cause galling and the freezing up of the nut on the bolt as if it were welded in place. Plus, he mounted the panels end to end without leaving a space between panels for expansion, and mounted some like diving boards totally contrary to the installation instructions taped to the back of each panel.

To make a long story short, the "approved" solar installer was a quack of the highest ranking, holding himself out to be something he wasn't. In the end I had him come out and remove all the panels and then told him to "take a hike." My friend and I re-installed the original 24 panels along with the other 56 we added to it.

I have read where people have complained about Enphase not being up to par on their warranty, but I have not had that experience with Enphase. On the contrary, I have had several D380s go bad and the monitoring system that comes free with an Enphase installation notified me of the problem right away. Enphase was quick to send a replacement inverter which I can replace in about 20 minutes; postage paid both ways by Enphase.

If I had waited a little longer prior to installation, I could have used the newer Enphase inverters that have a 25-year warranty instead of the 15-year one on the D380s, to match the 25-year warranty on the Sharp panels.

Have a friend who had an installer put a Sunnyboy 8000 installation on his home. Last month he got a billing statement from the electric company that was much larger than it should have been. Problem is that there is no way I can think of how to determine whether or not his system was delivering power to the grid or not during that whole month since there is no monitoring system like Enphase's Envoy monitoring system for the Sunnyboy that I am aware of. My guess is that his installer probably has the components installed improperly so that they are shutting down frequently when the grid voltage is at its low end, probably because he did not design the system for the lowest voltage drop from the inverters to the grid, thus causing auto-shutdown when it should not happen.

So far our system, since January 2011, starting with 24 panels to 80 panels pumping out electricity, has produced 46.7 MWhrs. Had it not been for the spa heater on the aquaponics system to keep the water temp at 80 degrees F for the Tilapia during the winter months (used 4-5 MWhrs), we would have had zero electric billing statements from the time we caught up after the 80 panels were put on line. Using blue gill this next winter; no heating required.

https://enlighten.enphaseenergy.com/public/systems/EUHq12526

I'm an Enphase enthusiast completely. When my D380s go out of warranty, I'll replace them with the new 25-year modules a branch at a time so that I have spare D380s for a while until I only have one branch left using D380s. My suggestion is to install a solar system yourself. It's hard work, but you won't be paying a premium for someone else to do it. You'll just be paying for the hardware essentially, and your payback will be much earlier than having had hired a quack to install it. How do you know if the installer is a quack or not prior to installation? You probably won't know until after the job is botched.

[bonaire]

Well, a string inverter install like your friend's could indeed be done wrong. Doesn't mean string inverter installs are a bad idea. Perhaps he has shading? Or, like you said, he may have a bad voltage setting. You can view the SMA front panel at certain times and inspect the activity. Has it started acting up recently? Does he take active notice of the front panel numbers and record daily output on good sun days? Perhaps one string of his strings has a bad module taking out a good portion of his potential production. When in doubt, call them out. Have him contact his installer for a module inspection.

For my own system, I have two PowerOne string inverters. Each has two MPPT controllers. So effectively, I have "four" inverters with 32 total module. If any one of the four strings shows out of spec voltage or amps during peak sun of a good sunny day, I can call out the installer for a string analysis. So far, no problems at all. A good install usually means a solid future of production.

[varnuke]

I'm not sure bonaire. I know he had it inspected by the installer and everything was supposedly okay. I looked up on SMA's website and found that they have a monitoring system available for their installations, similar to Enphase. I recommended that he get one of their monitoring systems up and running on his array so that he could monitor production daily, monthly, etc.