My neighbor's solar panel takedown made me question my whole grid-tie setup

Ran into Bob from two streets over at the transfer station last Saturday. He was dropping off three busted microinverters, said they lasted only 6 years before throwing error codes. I've been bragging about my 4.2kW array for a while now, but he brought up something I never considered. He showed me his meter readings going back to 2018, and his production dropped almost 30% after year five. We checked my app together on my phone right there, and sure enough, mine started slipping around month 40 too. I always figured panels just keep going until they die, but this degradation curve is real. Has anyone else tracked their annual output numbers against the spec sheet? I'm wondering if I should have bought cheaper panels and planned to replace them sooner instead of spending $9k on the premium brand.

2 comments

2 Comments

uma_williams1mo ago

...and that's exactly what my buddy Dave found with his setup. He's got a 6kW system from 2017, same brand everyone was raving about back then, and we pulled his numbers last month. Year one he was getting like 8,400 kWh, but last year it was barely 6,100. That's not just panel aging, that's some serious falloff. He checked the inverters too, and two of them had already been swapped under warranty. So yeah, the spec sheet says 0.5% per year degradation, but real world is looking more like 2-3% after year five. Made me feel better about my cheapo panels I got on sale, cause if they're gonna lose output anyway, might as well have saved the cash upfront.

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milam481mo ago

Wait, two inverters already swapped under warranty on a 6kW system that's only like 7 years old? That's bonkers. I mean, I get that inverters are kind of the weak link in any solar setup, but having 2 out of however many (probably 2 or 3 total, right?) fail that fast seems crazy. And the output drop from 8,400 to 6,100 kWh is way worse than the 0.5% per year they advertise, that's like a 27% total loss in 6 years, which is nuts. My cheapo panels from 2019 are actually holding up better than that so far, knock on wood (literally, I just knocked on my desk). Honestly, it makes me wonder if those premium brands are just selling hype and a fancy logo, cause the real world numbers don't lie.