I looked up the numbers for Aswan in the south of Egypt. Roughly 360 hours of sunshine or a bit more in the summer, 290 hours in winter months [1], so about 80

I looked up the numbers for Aswan in the south of Egypt. Roughly 360 hours of sunshine or a bit more in the summer, 290 hours in winter months [1], so about 80% of max. If we look at direct normal irradiance instead, a more appropriate metric, it varies between 7.93 kWh/m^2/day in June vs. 5.51 kWh/m^2/day in December [2], so about 70% of max. Hour-to-hour and day-to-day fluctuations are another thing altogether, and higher demand in winter (e.g. for heating) yet another consideration, but if we're purely interested in some sort of "seasonal correction" I guess you'd want to overbuild by 40% or a bit less if you set the angle of the panels in such a way as to optimize winter production at the expense of summer production, a common strategy. The closer you get to the equator, the less it matters whether you're in the northern hemisphere or the southern hemisphere. Aswan is at 24°N, a latitude at which you can still find a lot of smaller cities, but as you go to the south of that, infrastructure disappears and it might not be economical to build PV or solar thermal installations in the absolute middle of nowhere. Seems to be about the latitude to which DESERTEC proposes to lay HDVC connections. Not an expert though, just someone who can look up some numbers. [1] https://en.wikipedia.org/wiki/Aswan https://en.wikipedia.org/wiki/Aswan [2] https://www.researchgate.net/figure/Average-Direct-normal-irradiance-of-Aswan-Egypt_fig3_324538284 https://www.researchgate.net/figure/Average-Direct-normal-ir...