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cbdh19 said in October 29th, 2009 at 10:28 pm

The micro inverter almost sounds too good to be true. A few quick questions:

1. How much more does a system with micro-inverters cost exactly?
2. How long do micro-inverters last?
3. How durable are they?
4. How long have they been on the market, have they been able to prove themselves?
5. Are there any cons, because Ken doesn’t mention any in this video?
6. Am I making a mistake going with a traditional inverter for a system we’re having installed in a few months?

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Dave said in October 30th, 2009 at 5:29 pm

Great questions, I will make sure to ask some of them in my next interview.

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cbdh19 said in October 31st, 2009 at 8:13 pm

Dave,
Looking forward to the interview. I’m especially interested in the “how long to micro inverters last” question. If they last substantially longer than a traditional, centralized inverted (supposedly these last 10 to 12 years), then the costs potentially even out over the long term.

Always wondered how solar companies can get away with projecting your long term costs — without ever adding in the cost of replacing your inverter at year 10 or so of the system…

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cbdh19 said in November 1st, 2009 at 10:50 pm

I’m going to answer a couple of my own questions.

According to Enphase.com, the micro-inverters have a “mean lifetime” of 119 years. That’s right, they’re claiming a life that’s probably 4 times that of the panels themselves.

Of course, Enphase only guarantees the inverters for 15 years.

In comparison, Sunny Boy offers 10-year warranties on its inverters. And it’s my understanding that a centralized inverter lasts no more than 15 years. At which point, you’ll need to plop down probably a couple thousand dollars (or more) to replace it.

The micro-inverters are really beginning to intrigue me. Of course, my solar consultant is trying to steer me away from them, saying they’re too expensive.

But I wonder — if you add in the cost of replacing a centralized inverter at year 10 or 12, plus lower efficiency of the system, which means more panels are needed, and IF the micro-inverters really do last 100 years, maybe it’s not more expensive to go with micro-inverters…

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cbdh19 said in November 3rd, 2009 at 9:12 pm

I wanted to correct the 119-year figure. I misunderstood some of the info on the Enphase web page. In fact, Enphase predicts a 25-year life for its micro-inverters.

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