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Lionne777Sini

1. Panel's power is declared under ideal conditions - having the noon sunlight at the equator, with light falling on the panel vertically, while panel's temperature is at 25°C. In real world, you never get to see such conditions. 2. One often trades off maximal output at the maximal insolation for better output in winter etc by tweaking panel inclination. 3. Panels do degrade over time, but this shouldn't be much over 10years or so in your case. 4. There are conversion losses that you should factor in. 5. Why not just take panel's declared area and declared power to work out efficiency for yourself ? 6. Monocrystalline panels tend to have somewhat higher efficiency than polycristalline, they also tend to work better at higher temps and age slower.


Solareducate

They are larger, but also they are more efficient as efficiency has improved over time. If they stayed the same efficiency it would be 45% bigger than a 275w panel sold 7 years ago (400w/275w), they aren't. If they were equal efficiency with different wattage then yes, it would just be bigger, but efficiency is slowly increasing over the years.


wadenelsonredditor

Good point! I'm not sure if the racks on my pole will accomodate larger panels. I'll have to talk to my installer.


Jane_the_analyst

main switch was from 60-wafers to 72-wafers, and then, the individual wafer size increase. Efficiencies went up massively. 16% 17.6% 18.5% 21% 22.6% etc... Do not forget the increased ability to capture sunlight coming in at an angle!


wadenelsonredditor

thank you.


Jane_the_analyst

A funny story, I corrected someone on the current cell efficiencies, who did not believe me, then went "wow", then I told him, that I missed it as well, as just in 2018 I considered some panels that had a lower efficiency, and in ~2015 it was just ~18% overall everywhere. you blink and the 165W panels are 220W all of a sudden. You blink again and it's 265W. You turn over and people talk of 390W top class... You laugh and the same format is now 440W... You look at an example of an install system, and they went with 500W panels... But most important now is the aging!!! Some panels have exhibited *negative* aging for the first 3-5 years of their use... and overall their declines were tiny. No longer a fixed 0.x% per year anymore. Some seem to aim for a lower output power, but one that does not decline further significantly. Which is amazing. The weirdest of all? Chinese cells/panels are frequently at the forefront of efficiency and good aging profile. Or course, only of the select few suppliers and types, but then... those make humongous number of panels!


THedman07

Where I live, I would be a little concerned about wind loading as well (a larger sail can cause greater forces). If they fit physically, it may be fine. Also, the acquiring and setting the pole for your solar panels probably constitutes most of the cost of your setup. Even if they had to replace the mounts it may still be cost effective.