Germany is much cloudier than California and it is also at a significantly higher latitude, where the solar insolation is a lot smaller.

Solar panels above about 50°N almost never break even from a carbon budget POV over the lifetime of the panel once you account for mining, smelting, panel production, transportation and end of life processing.

You can fudge it if you have a location that far north with both a high altitude and low annual cloud cover but there aren't very many of them. AFAIK the only place with good annual solar potential at that latitude is in the Amur Oblast of Russia.

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That said, all of this applies to solar buildouts in the northern and central latitudes of Europe. Building panels in Spain/Italy/Serbia/etc and transmitting power is a wonderful idea that hasn't seen as much uptake as anybody with green ideas would like.