[tpoindex]

I have a 19 year-old, roof mounted, 6.3 kW nominal system in two arrays (east/west facing), 40 deg. north. I've never washed the panels outside of rain and occasional hail storm "scrubbing". Replaced a failed inverter two years ago.

My peak summer output is basically the same as when installed, making 36-38 kWh on a cloudless day. I'm actually impressed my panels haven't really degraded in performance over those 19 years.

[sgt]

That's really impressive and well built solar system, for it to last thta long. It shows how durable quality panels are. I have a 6 month old ~3.7kW system (6 panels in total), planning on installing another 6 very soon. My house is surrounded by trees so it's been a bit of a struggle in the winter.

[tpoindex]

My latitude plus east/west arrays are a struggle anyway. On the best (presumably cloudless) December day, I got 13.98 kWh. My 12/1/2025 through 1/31/2026 average per day was 10.32 kWh.

[manmal]

Panels should do 30 years, easy. Inverters will usually fail after 15y, and with batteries it’s unknown what the current gen will do - 15y, maybe 20? Definitely get LFP.

[noir_lord]

I’m waiting to see what the sodium packs look like before we do Solar PV (it’s on the list but not near the top so no urgency yet).

[malfist]

Sodium batteries are more grid scale I believe. They require seriously high temps to operate and thats best shared in massive banks

[noir_lord]

Not just grid scale, already been used in EV’s, less temperature sensitive than Li-ion, way more charge cycles but not quite as energy dense as lithium per kg but that’s not a downside in a static installation.

[sgt]

I've seen cheaper Chinese panels fail after less than 10 though.

[deepsun]

What the panels' technology / manufacturer?

[tpoindex]

SolarWorld, 175 watt, polycrystalline. I don't recall any model number (paper work is filed away somewhere.) ISTR mine were made in Germany. I think at the time my system was installed, there where some 225 watt panels available, but the 175 ones were a better price point per watt.

[edit - added technology]

[deepsun]

The SolarWorld company is no more :(

Which means your experience is irreplicable, other companies' solar panels may be crap.

[asdff]

Prices per watt of solar have fallen by so much over 20 years its absurd. You can probably buy the best and/or most costly residential panel on the market and still come well under whatever the median was 20 years ago. Probably well under a few standard deviations below the old median I'm guessing.

[slim]

looks like the planet is warming at the same rate your panels are decaying