Not sure if this is a WD or WDL issue, but at dusk my solar (davis vantage pro +) level drops as expects until suddenly it rises to 100% until it gets dark then drops to 0 almost immediately. I have done some searching on this and found a thread from last year but no resolution. Anyone else with this problem. It doesn’t seem to show up on graphs or logs
I still have this same issue as shown here In this thread from last year.
using 1-wire solar
The problem especially with a Davis solar sensor is that the expected level close to dawn/dusk is very low and usually in single figures so when working out a percentage if the sensor says say 4 and expected max is 5 then that’s 80% or sunny. This is not an exact science and close to dawn/dusk it gets worse! You can change the timing on the WD solar control panel to stop it seting the icon for x minutes after dawn and before sunset, you can also set a value to start/stop incrementing sunshine hours, this does lessen the issue.
Stuart
I know you have been busy Brian. When you get a few mins could you take a look that this issue of the 100% solar at sunset getting stuck. The thread I posted in the 2nd post is from almost a year ago, and still having the same issue and its also reflecting on my solar graphs at the end of the day. Thanks Brian.
One possible solution to this issue…Like I said… If Possible. Not sure how hard it would be to add a Sunset and a Sunrise Icon number in the clientraw just like for other icon numbers. That way instead of showing Sunny when its actually getting dark, it could show a Sunset icon. Just a thought.
This was added some time ago, unfortunately it does not seem to work correctly - at least for me…
Stuart
So maybe thats why the icon goes from…Lets say… Overcast to Sunny at the end of the day cause the Sunset icon is not engaging like it should.
I found your thread here Stuart…Hopefully sometime down the road this can get looked at again.
At first i thought it was the 1-wire solar only having that problem. But looks like the VP is doing the samething.
The problem here is that when you are dealing with low numbers the percentage calculated changes very rapidly when the numbers change, this has always been the way it has worked in the 4+ years I have had a VP and solar. To be honest I do not believe that there is much which can be done about this from a calculation perspective as the method of generating the expected values and subsequent percentage is very much an approximation and not a highly accurate way of doing this sunshine thing.
You can already adjust the way the solar calculations work where Brian has provided a number of tweaks to try to get around this and shadow problems where the reverse happens.
It is simply never going to get any better with the available solar sensor technology (Davis Oregon or 1-wire), significantly more expensive technology which measures direct (rather than total) radiation would help enormously but that is beyond the hobbyist. If we could get my other thread sorted so that the icon values in clientraw worked correctly at least it would indicate sunrise/sunset better which would help from a web page display point of view.
Stuart
Let me jump in to support Stuart here. Issue 1 is that measuring solar radiation correctly at very low sun angles is very difficult. The Davis sensor is the only one in common use that has an optical design that will even come close. Issue 2 is that many users will not have an unobstructed view the horizon. Issue 3 is that the mathematics are unfavorable, when the numbers are very small, in single or double digits, any error will generate a large error in the percentage.
It’s an estimate folks, it can be fine tuned, it can be improved with a better sensor, but it can never be perfect because it will always be just an estimate.
I know its going to be allmost impossible to fix, and thats fine. At this point its more about the Icon getting set to Sunset rather than Sunny when Its allmost dark outside.
OK so what we need to do is to monitor the icon number value in the clientraw file at sunset (and sunrise) and see what value is displayed. I know when I last looked mine was not working, however I have not looked recently as sunrise is well before I wake up and sunset is usually when I’m relaxing and not on the computer. I will try to take a look at sunset and see what shows. What I can say is that my icon on the main WD screen I think shows correctly. Anyway we need to check and then with hopefully a few folks confirming what they see we can get Brian to take another look.
Stuart
yeah…The icon on the main display Is correct. Mine will show the sunset display with 100% solar. I’ll also try and look at the clientraw files tonight and see what it says. Im more interested In getting the sunrise and sunset numbers so that you could also add them icons In the banners too. Cause atleast with mine, it can go from showing rain in the banner, then to Sunny cause of the 100% solar issue overriding the Icon.