Inverter Life Study - 15 years

[peakbagger]

Survey shows 34.3% failure rate for residential inverters over 15 years – pv magazine International (pv-magazine.com)

Kind of confirms my guess over the years for string inverters. Most seem to make it to 10 years as long as the house has a good low clamp voltage surge protector but if someone wants 20 years they had better buy and extended warranty. Knock on wood, I have few 10 year plus Fronius string inverters still cranking along. One was a warranty replacement for a utility surge with a prior SPD. My original inverter on my 20 plus year old system made it to 18 years.

[J.P.M.]

Survey shows 34.3% failure rate for residential inverters over 15 years – pv magazine International (pv-magazine.com)

Kind of confirms my guess over the years for string inverters. Most seem to make it to 10 years as long as the house has a good low clamp voltage surge protector but if someone wants 20 years they had better buy and extended warranty. Knock on wood, I have few 10 year plus Fronius string inverters still cranking along. One was a warranty replacement for a utility surge with a prior SPD. My original inverter on my 20 plus year old system made it to 18 years.

Thank you for the article. Among other things the piece reinforces the KISS principle by writing that inverter reliability is proportional to the reduction in the number of power electronic components. It also notes that outdoor installations also have shorter times to failure.

The piece seems to reinforce my opinion that for unshaded arrays a string inverter with fewer failure points than a bunch of micros or optimizers on a roof is better than a bunch of stuff in a hot and hard to get at environment where the components will be exposed to the elements including about the hottest and coldest place on a residence.

Also knock on wood, 10+ years and going well with a Sunpower rebadged Power one 5 kW inverter operating in my garage.
I've got aux. cooling fan on the unit that holds the operating temp. to max. of ~ 30 F above ambient garage air temp. at max. inverter output, less in approx. proportion to input from the 5.2 STC kW array. I've also got an identical replacement inverter a box when the current one takes a dump, hopefully that won't be for a long time.

Thanx again.

[peakbagger]

All of my inverters are in my nice cool basement bolted up to a concrete wall on the shady side of the building. One is oversized (3 KW for a 2.2 KW array) and the other is 2 KW for a 2.1 KW array. I have a spare 6 KW with dual MPPT in a box for backup. My original 660KW array (4 panels) is running fleabay Enphase 215s mounted in my basement. When I first put the array over 20 years ago I had the wire so I home ran all the panels to a terminal strip in junction box in the basement. When the old string inverter died after 18 years, I just removed a couple of jumpers and installed MC4 compatible connectors from the terminal strip to the four Enphase's which are also mounted in a nice cool basement. I am curious how long the Enphase's will last given that they are underloaded and in far nicer environment.

[J.P.M.]

All of my inverters are in my nice cool basement bolted up to a concrete wall on the shady side of the building. One is oversized (3 KW for a 2.2 KW array) and the other is 2 KW for a 2.1 KW array. I have a spare 6 KW with dual MPPT in a box for backup. My original 660KW array (4 panels) is running fleabay Enphase 215s mounted in my basement. When I first put the array over 20 years ago I had the wire so I home ran all the panels to a terminal strip in junction box in the basement. When the old string inverter died after 18 years, I just removed a couple of jumpers and installed MC4 compatible connectors from the terminal strip to the four Enphase's which are also mounted in a nice cool basement. I am curious how long the Enphase's will last given that they are underloaded and in far nicer environment.

That's 6.6 kW right ?

Did you need to get the re-work inspected or did you claim proficiency and sign off on it yourself ?

[peakbagger]

My first array was 660 watts. Back when panels were in the $4 a watt range and a 1 KW grid tie inverter was $1,500 The financial payback on that array was never dollars per installed watt was about $7. On the other hand it was at least partially responsible for career change from a dying industry to energy and renewables so intangible payback was pretty high.

No residential inspection "out in the woods". This type of work is generally considered replacement in kind locally. I felt I had adequate proficiency for my own use.

I keep it running mostly for nostalgia, I got installed in 2002 and was one of the first grid tied in my area.

[DanS26]

I have over 11 years on my matched set of Fronius 7.5 transformer based string inverters. 1.5 DC-AC ratio. I have them hung on a north side wall....never gets too hot but does get cold, some days below zero F. Both inverters are mechanically cooled which I believe is one of the reasons for longer life.

Have a Sunpower badged Fronius 7.5 as a backup. Just hope those big capacitors stay healthy.

[J.P.M.]

My first array was 660 watts. Back when panels were in the $4 a watt range and a 1 KW grid tie inverter was $1,500 The financial payback on that array was never dollars per installed watt was about $7. On the other hand it was at least partially responsible for career change from a dying industry to energy and renewables so intangible payback was pretty high.

No residential inspection "out in the woods". This type of work is generally considered replacement in kind locally. I felt I had adequate proficiency for my own use.

I keep it running mostly for nostalgia, I got installed in 2002 and was one of the first grid tied in my area.

Thank you. I've got a thermal flat plate water heating system I designed in 2005 that's fully functional and supplying most all the DHW for the house but somewhat nostalgic also.

[Ampster]

I also saw that article. I saw one interpretation that the study did not include some of the more recently produced inverters since the study started sometime in the nineties.

[Calsun]

Reliability starts at the design phase with the selection of the components and ends with the quality control people at the factory. My neighbor had their inverter fail in less than 5 years but I got nearly 10 years from mine. My Sunpower (Sunny Boy) inverter was crude compared to the Solis inverter that replaced it this month. 10 years is a very long time with computers and hardware development. My Sunny Boy inverter had a 2 line 16 character display on little diagnostic capabilities. My Solis has a high def full color LCD and much better diagnostic which can be accessed over the internet by the homeowner and Solis tech support people.

When electronics were being added to automobiles in the 1970s there were frequent failures of power transistor that could not take the heat. That is very seldom a problem with today's autos where the problem is more often with the software used that is created by inexperienced programmers who do not have a clue about how to test code.

Heat is not likely to be a problem unless an inverter is in a boiler room. They are designed to operate at up to 140 F degrees. What they are sensitive to though are power surges and power sags from the utility companies. As chips have gotten smaller and use ever smaller circuits they have become more susceptible to power surges with often only a few molecules of silicon that need to be disrupted to cause a part or the internal code to fail.

[Keepsake]

Had an IG5100 smoke today. Out of warranty. Internally there appears to be two identical power modules. Has anyone here had any luck just running one board at 50% capacity ? Details please ?

[DanS26]

Have you reached out to Fronius service? They are located in northern Indiana and will do repair work. If you call them many times you will reach very knowledgeable people.

[Keepsake]

During the warranty I went thru 6 fronius inverters. Not going to ever buy Fronius or repair for that matter. Now every Sunny Boy I ever bought and Schneider Electric is still 100%.

[DanS26]

Sounds like you have a bunch a spare parts now....a good electronics tech should be able to help you out. Good luck!

[Keepsake]

I got a spare S/E mppt60 -- problem is I have to climb on roof to re-wire panels. Strings now are at about 400 volts for Fronius. mppt60 max is 150 volts.
And what's with this forum site -- constantly logs me out

[nomadh]

I have the sunnyboy with the emergency standby power for 7 years now. 7000 module but only using a 5.5k array. Curious to see how it stands up. I maybe should look for a backup as I think they stopped selling them.