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Eight hours and 50 minutes of sun with the suns peak altitude at 22 degrees (Northern NH) , It all uphill from here. Usually, the transition to winter in my area is cloudy and with frequent fronts coming through the region making for lot of cloudy days, and poor production,usually that switches over to colder sunnier days after New Year's when I will see some of the highest peak output of my adjustable pole mount array. Cold temps lag the solstice by about 6 weeks so usually the middle to end of January is when I will see my inverter clipping despite it not being over paneled.
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The good news is that the earliest sunset is about two weeks ago, but the bad news is that the latest sunrise is two weeks after today's solstice....BSEE, R11, NABCEP, Chevy BoltEV, >3000kW installed -
Not so in my area of the world. Is this caused by mountain shading where you’re at?
Weather Underground says The days were getting shorter by a few seconds, but today is 0 seconds shorter than yesterday.
I read on an article in NASA that the atmosphere bends the sun so when we see it has just risen, it is actually one one sun lengths below where you see it. That can change the angle it comes up, but not make days longer or shorter.Comment
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Yes, today, the winter solstice is the shortest day, but the latest sunrise does not coincide with the earliest sunset.BSEE, R11, NABCEP, Chevy BoltEV, >3000kW installedComment
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This time of year, I can look roughly east at just about the horizon. I can see things getting brighter and then the sun goes behind a local mountain. I can see its behind there but no direct light until about an hour and half when it pops out from behind a steep vertical slope.I have the later sunrise effect. Of course in the afternoon after about 6 Hours of sun, the sun drops below and another mountain. but with snow pack on the ground it sure is bright. I even got out the roof rake and cleared my roof panels to get all four arrays running.
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Local solar time is not the same as local clock time for 3 reasons:
1.) Daylight saving time may be in effect.
2.) Local latitude will in almost all cases be different by up to +/- 7.5 degrees of longitude from the time zone meridian.
3.) Perhaps the least commonly known and so least commonly understood reason is due to something called the "equation of time" ("E.O.T.") which takes into account the perturbations in the earth's rate of rotation in its elliptical orbit and also some additional and relatively minor perturbations caused by the earth's "wobble" on it's axis both of which affects the time when the sun crosses the observer's meridian.
There are various empirical algorithms/equations to account for this, most of reasonable accuracy within a few seconds of one another. The E.O.T. varies from a bit less than +/- 15 minutes or so over the course of a year but is not a regular function and gallops around a bit with 2 local minimums and 2 local maximums throughout the year.
The atmospheric parallax (bending) only effects the sun's apparent altitude above the horizon (the vertical plane) but does not act in the other plane and so does not affect the apparent time.Comment
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Sunrise and sunset times in Chicago (timeanddate.com)
Plug in your own location to find "solar noon"Comment
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Wait! Don't we get an extra hour of sunlight due to daylight savings time or is that in the summer?
We don't do that clock re-setting nonsense here in Arizona.
Today, we'll see about 10 hours between sunrise and sunset but how many "sun hours" is that? Let the debates begin. Ha!
At my location in Phoenix, we see much less production in the winter of course. Since the electrical demand is much lower we still end up with a surplus over the winter months. April and May are when we really build up the grid-tie reserve for the summer A/C season. December is usually our worst month but still do about 20% over our needs.Dave W. Gilbert AZ
6.63kW grid-tie ownerComment
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When making production plots, I had to take solar noon into account
to get consistent results. Have a chart day by day, can be off 20
minutes from standard time. The problem with production here is
the clouds. Most of the year I can get 8 solid hours when the sun
is bright, but that is very, VERY rare in Dec.
Snow usually happens at night, panels are cleared for the next sun.
Bruce RoeComment
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