davidmcbeth3 wrote:Not just loss in sunlite hours in winter ... its the angle and power of the light that is able to shine.
I think, from my memory, in summer its 1500 W/sq. meter .... winter about 500 w/sq. meter. So not only is your hours of sun shortened so it the "power" of the sun that hits the panels.
All that is required to debunk this is to use the insolation data readily available from NASA, PVWATTS, and many other sources. It is true that due to the tilt of the earth a panel laying directly on the earths surface and pointing straight up will receive a cosine function based decrease in sun energy with respect to latitude. But wherever you are on the earth you can tilt your panels to point directly at the sun for any given seasonal solar noon.
It turns out that at the top of the atmosphere a panel tilted directly toward the sun receives about on average 1,367 Watts/Sq-M (a bit more than 1,400 at the earths annual closest approach to the sun, and about 1,330 at its annual furthest distance from the sun), and at the surface and at sea level at solar noon the same orientation of panel will receive about 1,000 Watts/Sq-M regardless of latitude (this being why the STC [standard test condition] for solar panels universally utilizes 1,000 Watts/Sq-M).
Panels at higher elevations actually receive more Watts/Sq-M than at lower elevations, eventually approaching 1,367 if you go high enough to leave the atmosphere. That is why my charge controller manufacturer warned me that if I lived at an elevation of 3,000 ft. or greater I would need to get their next size up (I.E., more expensive model) as to my charge controller, but for my 1,200 foot elevation they did the math and said I was going to be OK. They were given my latitude when I requested that they assess this (being concerned as I am that to save money I had to buy components at the lower end of the money scale, meaning components that are potentially marginal). If it were true (as you state) that less sun hits a panel titted directly at the sun with rising latitude, then the charge controllers manufacturer would have chuckled at me and told me: "No worries, as at your high latitude angle there won't be as much sunlight as at the equator anyway. But alas, in the end they were ONLY (and highly) concerned with my elevation, and not with my latitude.
It is true that my area receives about 4.1 insolation hours per day overall on average, and as much as about 5.9 in the summer and as little as 2.1 in the winter, but the sun is the sun, and if you can point to it directly at solar noon you will receive its maximum possible energy (on a perfectly clear day of course). The only deficit of latitude is the disproportional amount of time available per day to point at it, and not in the energy it delivers.
The cosine of 90 degrees (the latitude of the north and south poles) = 0
The cosine of 50 degrees (Germany's latitude is somewhere in this ballpark) = 0.64
The cosine of 40 degrees (I,m in this ballpark) = 0.77
The cosine of 0 degrees (the latitude of the equator) = 1
But teams of scientists studying Antarctica (albeit admittedly that they only generally stay during the summer months) routinely utilize solar panels to provide their energy, as it isn't going to conveniently come to them in any other form. Even there you can angle them to point straight at the sun, thus proving the irrelevance of this cosine matter.