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OutBack FP1 w/ CS6P-250P http://bit.ly/1Sg5VNH -
Probably several things at work, starting with more components and connections that can fail. I'd think what's probably a lower temp. environment of a ground mount might lower the failure rate of most electronics, but with micros there are simply more of them to fail. Hard to tell and not universally applicable, but ground mounts are probably easier to work on/assemble. That may make for a more robust wiring job. Seems to me that overall, ground mounting, while not always possible, and probably more expensive, will generally, if done right, result in a "better" solar installation in terms of robustness regardless of the inverter scheme used.
So, ground mounted systems with micros may be less troublesome than roof mounted systems with micro inverters, but ground mounted systems with micro inverters may well be less reliable than ground mounted systems with string inverters.
My guess is reliability problems with micros start with poor design for a tougher (roof) environment and are compounded by more components that can fail. At least with a ground mount, temps. are probably lower and accessibility is a bit easier most of the time.
If I'd built the desert magnum opus I designed and got through plan check, the PV design would have been a grid tied ground mount with unobstructed view and with a string inverter.
So, why do micros fail so often: 1.) There's 10 or 20 times as many of them to fail. 2.) Quality may be a problem. 3) They do not like higher temps. than any other electronic components.Comment
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Howdy Suneagle and All,
Good question, we havnt done any ground mount systems with mico's most of the ground mounts we have done have been with SMA and Fronius and quite a few ABB's in the old days, the SMA and Fronius have both been great with a few more failures from ABB so we dont use them anymore. In fairness to mico's the bulk of the problem's were with the early versions but in saying that we had 2 dead on arrivals on a new install a few months back.
The other thing about mico's is they can be very annoying to installers as many newb solar system owners wig out if one panel is making 5 watts less than the one next to it and want someone out to fix the system when in fact there is nothing wrong with the system, Most people want micros because of panels level monitoring, but I think the monitoring that comes with the new fronius inverters is excellent (we use a lot of them on single phase installs) and certainly able to give you enough info as to '"is the system functioning correctly"
So is it the heat on the roof's that stuff up the micros/ optimisers, I think so, and maybe combine that with crap installs as Butch points out, and being that we are in Oz and it gets hot ...damn hot I would rather my inverter (s) live in the shade under a roof, not under a panel on the roof, cheers
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I just went through the same thing with my Sunworks 8.28kW system here in CA. Noticed at year 2 PGE true up that I was paying way more than last year. Looked at SunPower panel monitoring (only 60 days available) and noticed about a third of my 24 panels were not doing well. My installer replaced all of the microinverters (SunPower provided the parts). I'm figuring I'm out at least $200 for under performance in the 4 months just prior to micro replacement. I was under the proposal numbers by about 600kWh in year 1 and 1300kWh in year 2, but SunPower doesn't actually have a "power production" warranty, they only warrant the parts and will replace. While the installer provides "monitoring", it is only on an alert basis for critical failures, not for 5-10% power reductions.
So Tommygun45, did SunPower ever compensate you for lost power? I'm wondering if I should hit them up?Comment
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