Yes, on hot summer days I also see the sensor overshooting the prediction. It could of course be that the sensor drifted from its initial calibration, though the current weather might indicate it's not the case, but rather as you noted, it's some atmospheric effect in certain months/seasons.
In WeeWx, you need to add a new observation type, maxSolarRad which you need to append to the database columns and use in the skin config. On Sunday, April 21, 2019 at 7:33:50 PM UTC+2, Greg Troxel wrote: > > kobuki <nls...@gmail.com <javascript:>> writes: > > > Yeah, thanks for the insight. I'm aware of the various atmospheric > models. > > I want to find something that has been a) proven useful for solar power > > predictions; b) has a working open source python implementation. While > the > > scientific background is very interesting in itself, I don't intend to > > re-invent the wheel. I do have a fairly good solar and UV sensor for my > VP2 > > weather station. An interesting fact, this spring the solar sensor W/m2 > > curve almost completely overlaps with the built-in solar model > prediction > > (theoretical max. irradiation) in WeeWx, and we do have unobstructed > clear > > sky and sunshine these days. So I'm hoping to do something similar with > my > > solar power system. > > I wasn't aware there was a solar model in weewx. I have on my todo > list to compute the irradiance with a clear sky, and to graph measured > irradiance vs theoretical max. > > I have seen irradiance values higher than what I believe theoretical max > is. On a completely clear day, no, but on days with some clouds. My > assumption -- with no good basis -- is that there is some sort of > lensing as the sun passes the cloud edge and there is a temporary > beyond-max excursion. This is part of why I want to graph the > fraction-of-max. > > > I've found 2 worthy contenders in the subject so far: > > > > https://github.com/pvlib/pvlib-python/ > > https://pypi.org/project/solprimer/ > > > > I need to indulge myself in them a bit to see which might fit my needs > the > > best. I think the first one might be better suited and it's also > actively > > developed, but I just don't know yet. > > Thanks for the links. > -- You received this message because you are subscribed to the Google Groups "weewx-user" group. To unsubscribe from this group and stop receiving emails from it, send an email to weewx-user+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/d/optout.
