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Solar Radiation Max value

Discussion of the Cumulusutils tool and website generator.

Moderator: HansR

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rogerthn
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Solar Radiation Max value

Post by rogerthn »

Where is Cumulusutils Solar Radiation Max value read?
https://rogerthn.se/cumulusutils/ do say 56 W/m2 while CumulusMX Dashboard say High 12 at 11:09
Edit:
Seems to be Current theoretical max solar radiation.
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HansR
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Re: Solar Radiation Max value

Post by HansR »

The value displayed in the Dashboard is the sensor value and below that is the max theoretical value.
There has been a lot of discussion on how to calculate the theoretical max value. Search on the forum and you will find some threads about the subject from the beginning of times.

However it truly is complex because it depends on what you measure: which frequency (or frequency package) and with what you measure it. So a theoretical max has a relation to reality of atmosphere, angles, frequencies and sensor sensitivity for certain bands. There is an awful lot of literature about this on the web. Have fun.

And CumulusUtils - as it is by conception - is only the messenger: it displays values it finds (of gets from) in the CMX database. So if you really want to go in depth about the how of the calculation of the max value or different sensors, you'd better start a threat either in CMX forum for how CMX determines the solar max values. Or in general if you want to go theoretical.

It is a very interesting subject btw.
Very educational in relation to your solar cells on your latitude as well: which frequencies do they use for generating electricity? How do they capture most energy? Should they turn with the sun? :D :groan:
https://meteo-wagenborgen.nl / Cumulus 3.9.4 (build: 3099)
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rogerthn
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Re: Solar Radiation Max value

Post by rogerthn »

HansR wrote:
Sat 09 Jan 2021 10:34 am
The value displayed in the Dashboard is the sensor value and below that is the max theoretical value.
There has been a lot of discussion on how to calculate the theoretical max value. Search on the forum and you will find some threads about the subject from the beginning of times.

However it truly is complex because it depends on what you measure: which frequency (or frequency package) and with what you measure it. So a theoretical max has a relation to reality of atmosphere, angles, frequencies and sensor sensitivity for certain bands. There is an awful lot of literature about this on the web. Have fun.

And CumulusUtils - as it is by conception - is only the messenger: it displays values it finds (of gets from) in the CMX database. So if you really want to go in depth about the how of the calculation of the max value or different sensors, you'd better start a threat either in CMX forum for how CMX determines the solar max values. Or in general if you want to go theoretical.
OK, I did compare daily high from CumulusMX Dashboard with Current theoretical max from realtime.txt :bash:
HansR wrote:
Sat 09 Jan 2021 10:34 am
The value displayeIt is a very interesting subject btw.
Very educational in relation to your solar cells on your latitude as well: which frequencies do they use for generating electricity? How do they capture most energy? Should they turn with the sun? :D :groan:
I do poll every ~10 second but with snow on the panels :|
PS
https://rogerthn.se/weather2/picture.php
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HansR
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Re: Solar Radiation Max value

Post by HansR »

rogerthn wrote:
Sat 09 Jan 2021 12:29 pm
I do poll every ~10 second but with snow on the panels :|
:lol: limits of solar power.
Wouldn't it be a great idea to have a heater in those panels? To keep them just above 0 degr.?
Like they have in the Davis stations or in the water pipes in Scandinavian countries (if I remember well from my visit once to a Norwegian island just above the polar circle).
https://meteo-wagenborgen.nl / Cumulus 3.9.4 (build: 3099)
Davis Vantage Pro 2+ / Raspberry Pi 3 Model B Plus Rev 1.3
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rogerthn
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Re: Solar Radiation Max value

Post by rogerthn »

HansR wrote:
Sat 09 Jan 2021 12:36 pm
:lol: limits of solar power.
Wouldn't it be a great idea to have a heater in those panels? To keep them just above 0 degr.?
Like they have in the Davis stations or in the water pipes in Scandinavian countries (if I remember well from my visit once to a Norwegian island just above the polar circle).
Heater will not be economic since the sun doesn't shine for to many hours while the temperature is below 0 and there is ~50m2 to warm up :(

I did notice that the snow started to "slide of" and using my 5m telescope brush there is no snow left on the panels resulting in 1.362 kWh today :D
hmmm, less than 2 SEK for an hours work :lol:

BUT
The efficiency of solar panels is changed with 0,4% per degree and there have been some discussion regarding cooling of the panels during HOT summer days.
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