RobG Posted January 21, 2019 Share Posted January 21, 2019 Hi the Forum. Why is there such a difference in maximum PV amps on sunny compared to partly cloudy days? PV is N facing 3000W and on partly cloudy days I see maximum of 3100W/56A but on sunny days maximum of 2300W/43A approximately. Is this normal? Thanks Rob Quote Link to comment Share on other sites More sharing options...
___ Posted January 21, 2019 Share Posted January 21, 2019 2 minutes ago, RobG said: Is this normal? Yup. Two reasons. 1. Cooler temperatures. On days with lots of sun, everything tends to bake a bit warmer, and PV panels don't like to be hot. They make less power under those circumstances. 2. Cloud flare effect. As the sun shines through the edge of the cloud, it tends to flare and you get insolation spikes that are higher than the 1000W per square meter that PV panels are rated at, giving you a nice big spike. Arandoza 1 Quote Link to comment Share on other sites More sharing options...
Gabriel_2018 Posted January 21, 2019 Share Posted January 21, 2019 3 minutes ago, RobG said: Hi the Forum. Why is there such a difference in maximum PV amps on sunny compared to partly cloudy days? PV is N facing 3000W and on partly cloudy days I see maximum of 3100W/56A but on sunny days maximum of 2300W/43A approximately. Is this normal? Thanks Rob Yes it is. You have to consider cloud edge effect, which can add 20-40% extra radiation. Arandoza 1 Quote Link to comment Share on other sites More sharing options...
RobG Posted January 21, 2019 Author Share Posted January 21, 2019 Thanks for the answers. Quote Link to comment Share on other sites More sharing options...
SilverNodashi Posted January 21, 2019 Share Posted January 21, 2019 1 hour ago, plonkster said: Yup. Two reasons. 1. Cooler temperatures. On days with lots of sun, everything tends to bake a bit warmer, and PV panels don't like to be hot. They make less power under those circumstances. 2. Cloud flare effect. As the sun shines through the edge of the cloud, it tends to flare and you get insolation spikes that are higher than the 1000W per square meter that PV panels are rated at, giving you a nice big spike. I know some people like that as well ___ and Gabriel_2018 2 Quote Link to comment Share on other sites More sharing options...
Gabriel_2018 Posted January 21, 2019 Share Posted January 21, 2019 1 hour ago, SilverNodashi said: I know some people like that as well To be hot or not, is that the question? Quote Link to comment Share on other sites More sharing options...
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