I had planned on doing a product review, but it evolved into this:
My ground mount system has been running for 5 months without issues, except those caused by me.
The system consists of 10 Trina 320 Watt modules, 10 Enphase IQ 7+ micros, Enphase IQ Envoy.
The system is set to zero grid export.
Trina modules – Well they just work. Don't know what else to say other than Trina provides very good documentation in REAL English.
Enphase: I was a bit leery of Enphase, as the company had financial and quality problems.
After a LOT of research it seems the company has made a lot of improvements in both areas. Enphase replaced the people in the top 2 management positions. The new guys admitted to the companies problems (that's novel), and said how they would fix them. Time will tell.
IQ micros: Pretty sophisticated, and Enphase claims they can adapt to the varied and changing requirements placed on pv by utilities and agencies in the U.S.
Pros: I have partial shading where the modules are located, and the micros handle that well. Standard inverters with optimizers do this too – as well ?
Enphase support has been excellent so far. I called twice with install / setup issues and waited < 10 min to be connected to competent / patient people.
Installation was basically plug & play. I used the Enphase premade cable. Very easy with no diy connections to leak later. $$ though
Probably all, micros shut down without a connection to the grid. I checked a few in my system, and they put out about 1V when not sensing the grid.
Only 2 wires are needed between the micros and the breaker panel, saving some work, and money.
For me, another bennie, was that the local building official was comfortable with AC throughout the system. The GTI I was considering would have brought 500+ V DC to the disconnect at the house, and he would have wanted an engineer's review of that.
For the most part micros eliminate stringing calculations required by most central GTIs – a biggie for me as it would have been difficult to string the # of modules I bought. Cold temp voltage calculations would have added to the difficulty. -8F at twilight this a.m. The micros don't care.
Micros (especially the same type) should allow me to add a few oddball modules to my system at a later date fairly easily.
Cons:
More expensive than a quality GTI of similar capacity. Using optimizers bring the costs closer.
More failure points – though the rest of the system should still work if a few go down. They are wired in parallel.
I guess the Enphase phone app system makes system setup pretty easy, but it doesn't work with my old, bargain basement phone. BUT I called Enphase, and one of their very patient tech people spent about 20 mins on the phone and walked me thru the process.
Enphase comes out with new devices fairly often which aren't fully compatible with their older products. I'm sure you can mix the micros, they just won't talk to other devices.
Envoy: Their communication device.
It “talks†to the micros thru the system wiring, and to Enphase thru the internet. It provides a per device look at the health and operation of every device in the system about every 10 minutes, including a lot of historical data, and Alerts.
I received an email Alert from Enphase telling me the system wasn't working. It was my fault.
I find the per-module monitoring helpful as it lets me I.D. shading sources – firewood to be.
The “Enlighten†web based svc allows direct contact with Enphase for warranty and diagnostic purposes – I'd rather not use this.
The Envoy also is capable of revenue grade metering.
Racking:
I used 2 3/8†steel fence posts set into concrete for the bases and top rails, 3/4†emt for braces. Modules sit on unistrut. I couldn't find hot dipped strut near me, but would strongly suggest hot dipped if you go that route.
I hope someone finds this helpful.
PIX and updates later.
Pete
