Solar% do not respond.

Apparently in winter, the solar% setting does not respond.
I can add or remove and do not react.
I have everything set up correctly but in winter it is a problem that sunrise or sunset are too high solar%.
It’s a completely cloudy sky, and it reports 100% of the sunshine and I have no other way to damp it.
I think it’s a little hairy, because with older versions like B81 this problem was not.


solar%.png

what weather station type?
also the attenuation is not normally set to 0

VP2.
Still, it is utterly tall, it would want a larger range, perhaps set to negative value.
I can say that in the summer time I have to add to a bigger hunt.
The cloudy sky loading the sunshine before dawn and dusk is about 20 minutes each day, which is quite high value.

What I dont understand is that you say you have a VP2 but your solar readings show a temp in

What you see in the picture do not take seriously, it’s just a rough installation on the other pc.
Yes, the station is the original VP6163.
Here are the new settings pictures.
I can also add pictures from the morning and before dawn when I wake up :slight_smile:


sun mon.png

when you have very small values, i.e in winter, especially close to sunset/sunrise, then it could be hard for your raw solar reading to be close to what it should be (which is what the % is based on)

I can add or remove and do not react.
its not very clear exactly what you are doing here

As Brian says the issue at sunrise and sunset it the theoretical max value is small as is the reading from the sensor so you will always get percentage values which skew the solar conditions. It’s a fact of life. The only way is to stop it setting a condition until you get higher values which gives a more realistic percentage and thus condition.

Stuart

Here I attach a new snapshot at 8:00 AM.
Sunrise 7:36 AM and outdoors again cloudy sky and as we see in the picture at 23w sunshine is 100% solar and that’s the problem.
I can not dampen any more because it’s not like that anymore.


solar.png

According to my maxsolar script your expected max should be around 21w/m2 so with an actual of 23 yes its over 100%. That’s just the way it works. Your expected max for your location does not reach 100w/m2 until around 8:53 local at this time of year. The same situation arises in summer but because the sun rises earlier and is stronger the time this problem exists is shorter and so does not skew the conditions to the same extent.

This is not a specific issue for your location but a world wide issue when using this method to estimate solar conditions. If you need high accuracy then you need a different kind of solar sensor, one which measures direct solar radiation, not the Davis one which measures global radiation (including reflected radiation).

Stuart

Yes thanks for your reply.
Unfortunately, a different solar sensor than Davis is hardly probable.
The problem is that everyday sunshine I put on a table, and if it’s cloudy for a whole week and I’m going to measure 20 minutes of sunshine in a day, that’s a lot of hours in a week.
People are asking me why I have a sundial in the table when a month of cloudy or inversion is needed.
It seems that this problem will not be solved.
But the truth is that in the wd version of 10.37R this problem was not.

This issue has always existed to a greater or lesser extent. Sometime ago Brian tweaked the expected max solar calculation to reduce it quite a small amount as it was running too high, this will exacerbate the sunrise/set issue a bit but not hugely. There is an option on the solar control panel/thresholds tab to set a number of minutes after rise and before set to prevent WD increasing the sunshine hours, you cold adjust this to stop it adding minutes to the value, however this does not stop the solar condition being set. You can also use the Time to set Icon to try to prevent these low values giving a wrong indication and there is a flag on that to affect sunshine hours as well.

Stuart

Perhaps if it was possible to set a wider range of adding% to -5 to 5%


solar.png

Changing the attenuation will affect the whole range of readings (not just at sunrise/set), not what you want in fact I dont know if Brian still uses it or if he does how exactly it works, its not a variable in my maxsolar script.

Attenuation is the reduction in the solar energy reaching the ground caused by the atmosphere, which means if you are high up say a mountain this effect is reduced and increases the solar energy reaching the ground at that location. If you increase atmospheric attenuation you will reduce the expected max which in turn will make your problem worse.

There simply is no way to avoid this within the current design using a Davis or one-wire solar sensor. I know how all this works as I spent months some years ago investigating all this and writing my maxsolar script. If you get an expected max of 5 and a reading of 4 then the result is 80% but the same reading on an expected max of 80 is 5%.

Stuart

Well, I understand that thanks for the information.
But I have to insist that this setting is inoperative.
You can do the test yourself, add and subtract the value and you will see that no change.
He tested the older program and it’s ok.
Setting the value to 0 or 5 can be seen at solar%.
Nice day.


solar.png

Well as I explained I was not sure it worked and to be honest I do not think it should be an option given what the definition of atmospheric attenuation is.

Just set the options to not set the icon or sunshine hours until sometime after sunrise that way you will not get spurious sunny conditions, or at least it will reduce.

I am not going to comment further, you have the advice and an explanation of why it happens. This is NOT fixable using this method of calculating sunshine hours, only reducible as I have explained.

Stuart

This function serves to dampen, but apparently damaged.
I went back to version 10.37R310.