ELROY wrote:I am leaning towards the Enphase because of their proven track record. I had not even heard of the Power One Microinverters till yesterday when I was looking at Solartec USA on Ebay was pushing this microverter with their Telaphase 280 watt panels. But it looks like you might even need more connectors to make it work. Incidentally, Power One headquarters just happens to be located in my city of Camarillo.
I agree that at 280W the Power One might make the most sense, but I wonder if they really only offer a 10-year warranty. That's pretty low for a microinverter, IMO.
ELROY wrote:Also, with a 240-250 watt panels, do the M215 microinverters just "lose" anything over 215 watts?
Yes, the output power is hard limited to no more than about 225W.
ELROY wrote:Are others actually getting the 225watts mentioned here also?
Yes, that is what people get from the M215 when it is limited. We get about 199 from the M190s we have. We see this occasionally in the wintertime with the 235W panels we use them with.
ELROY wrote:If so. with a 240-250watt panel, isn't the 225watts about the max you would get AC anyways?
Yes, that's the point. You will probably never limit the output of a 240W panel using an M215 microinverter. With a 250W panel, you might limit a couple of times a year, if that. Keep in mind that the peak efficiency of the inverter is 96.3%, so the panel would need to put out over 233W to hit the 225W limit. In order to produce 233W from a 250W panel the sun needs to be near the boresight of the panel and it needs to be quite cool. For a house like ours with a south-facing roof, the sun only gets really close to the boresight in the spring and fall. In wintertime, it needs to be even colder for the limit to be reached.
ELROY wrote:Any other sources for good deals on the Enphase Products?
A Google search gave $142, but I don't know how much shipping is.
ELROY wrote:If I supply my own parts for the job, am I still okay with all the rebates/tax deductions as long as I keep the receipts?
That's what we did. But we only dealt with the federal rebate and my local (tiny) utility.
ELROY wrote:If I purchase all these parts, do I have to install them all by the end of the year to get credit?
Yes. It is tied to when your array enters service. My understanding is that the federal government considers all purchases to have happened in the year when the system enters service.
ELROY wrote:Or does it not matter when I actually purchase them since the timetable starts with the permit application/installation/finish of the entire job?
Service entry date for the federal tax credit.
AndyH wrote:Maybe I'm missing something here, Reg - can you explain why you suggest MC4 connectors have high connect/disconnect forces? My panels use MC4 connectors - one finger and one thumb on each side for dry assembly is overkill.

When unplugging, one inserts the disconnect tool and holds the tool and one connector while tugging the other connector. A bit of silicone-based grease on the o-ring during initial assembly should make for very easy disconnects in 5 years when it's time to replace the first couple if inverters.

If you use only MultiConnect brand (or any single brand) MC4s for everything I think your experience is typical. So anyone building a string of panels will likely have good experiences mating/demating MC4s. However, PV panels and microinverters are made by different companies and the chances that they use MC4 connectors from the same manufacturer is pretty low. My experience with Sharp panels and Enphase microinverters is that one way (like male PV, female microinverter) they go together fine, but the other direction is nearly impossible to mate or demate. It's particularly challenging to do it when the connections are being made underneath the panel.
AndyH wrote:Bulkhead connectors are fastened to the case/box/bulkhead, but the electrical connectors inside are not. In other words, any connector stress is passed to the case and not the wiring. Unless you think the company is using a special bulkhead connector with hard connections to a PCB?
http://www.aliexpress.com/store/product ... 30167.html
I'll just say that the mating force for some of these connections is MASSIVE. The fact that Enphase moved from bulkead connectors to pigtails makes me think they had some sort of problem with them.
One other problem with bulkhead connectors is that the nut is inaccessible once the case is sealed. If the connector gets rotated, it may be impossible to retighten it without damaging the internal connections.