RE: Microinverters are on their way out
solareye must be working for SolarEdge or some competitor. I am an Electronic engineer and find his comments show an anti-micro inverter bias. I don't work for a solar company.
1 and 6. These inverters are not in any more hostile environment than a wall-mounted inverter that is in full sun exposure. In fact, these micros are shaded under the panels, and are fairly free from water due to the panel above, and careful sealing. Mounted correctly, they get airflow top and bottom, from roof air convection and wind. Not the hostile environment described, unless the panel is not given sufficient clearance as recommended. 4 to 6 inches from panel to roof gives sufficient airflow. Micros produce very little heat, a 6x6" box and a few watts, mounted with space under a panel do not dramatically increase heat- a few degrees maximum. Remember, its only a few % of the panel's output, not a few% of 30 or 40 panel's output that is waste heat in each micro.
2 and 7. Lower efficiency rating- give me a break! This is nit-picking. He quotes SolarEdge at 98.3% peak, EnerPhase claims 96.3%. What he does not say is that the individual MPPT trackers in EVERY micro gives up to 50% more power in some conditions of shading than a single inverter system does. He is missing the big picture- 50% energy not getting to the inverter in a series string is a tad more loss than a couple % of nearly unobtainable "peak" efficiency. Series string panels limit total energy due to shading, way more than micro inverter systems. Each Micro has its own individual MPPT control, adjusting for conditions on its single panel, not one MPPT adjustment for a dozen or more panels! Talk about nonsense!
Electronic professionals (not salesmen like this guy) have been watching this trend for years and have given it accolades due too the redundant low-power approach, that encourages reliability. No single part failure to shut down the whole system, as is likely in the highly-stressed multi-kilowatt typical inverter. If a inverter or panel fails, it disconnects, and does nothing. Yes, the Enerphase M215 limits power to around 215-220 Watts output. You can expect a long time continuous power with 240-275 Watt panels before panel degradation happens, or you can get the minimal panel power and save a dollar or two. Reality is, a 250 watt panel rarely gives peak power output, due to sun angle mismatch, dirt, temperature, wire loss, etc. so oversizing ("rightsizing") panels rarely cause power limiting! OTOH, series strings are limited by the weakest panel in the string. Too bad. A typical 250Watt panel generate around 220 Watts in typical non-tracking configurations.
solareye knows his technology "is on the way out" so he attacks micros.
3, 4, and 5. Far more expensive? the only difference is the inverter. Panel prices are market-driven. The M215 (the current production model) is around $148.00 each. The supposed "$400 to $500 per microinverter replacement" is a flat out "exaggeration." You can buy packages of panels and microinverters for about $1.80 to $2/Watt (less hardware, mounts, wiring). Difficulty of installation!? panels mount like panels. Plug in to the ac bus cable, the panel, and wire the bus to the to the service. How long does it take to plug in a plug!? If a failure occurs, you don't have do anything. Power output drops according to the failed inverter or panel. 1/32 power loss in a 32 panel system. When you feel like it, you call someone to replace the failed inverter. No emergency, no weekend calls. In a series system, when the inverter fails, the whole system goes down. Think about how much a 7kW inverter failing will "wipe out a micro inverter system owner's return on investment" as he claims? A $148.00 inverter and an hour of time vs an expensive 7Kw inverter and several hours of time (and total power shutdown). This guy is selling you a line. He clearly likes SolarEdge, which is an excellent product, BUT is not being unbiased as he tries to imply. His bias is clearly showing. From an electronic standpoint, the smaller inverters are more likely to last many years, due to the lowered component stress achievable. Go on their website- they have dozens of helpful articles and whitepapers addressing the many false attacks they receive from the entrenched single-inverter competitors. Don't listen to someone with this kind of bias!!!