Who knows that Germany has the world’s biggest installation of solar power? Probably not as many who are aware that Germany is a long way from the equator — at 51 degrees north, it is further away than Tasmania and even the south Island of New Zealand. That latitude only gets 62% of the sunshine as an equatorial location (cosine of 51 degrees is 0.62). Germany is also notoriously cloudy.
Obviously not a great location for solar panels. So why did they do it?
Further, those clouds stick around because there is little wind on many days.
Fortunately, they have a new word for their predicament: dunkelflaute.
Dunkel means “dark”; solar is simply not available half the time, and solar power production is significant for only around six hours a day even when the sun is shining. Flaute is “doldrums” – when the wind is not blowing. So the “dark doldrums” are times when solar and wind power is not available in sufficient amounts.
This chart is just wind [green] and solar [yellow] for March 2016 in Germany. Red lines are periods less than 5GW. Spectacularly intermittent.
Remember, you need to have coal or nuclear already running, or have gas turbines ready on standby, as backup for all that renewable capacity — for when it stops. Renewables do not reduce the need for coal or nuclear, except to replace some of it with gas capacity. Gas companies love renewables.
As for home usage in Germany:
UPDATE: A reader writes that the house pictured is actually a small pharmacy near Brussels. There was large financial support for home installation of solar PV in Belgium, since drastically reduced. Still, Belgium is a similar distance from the equator and has similar weather, so I’ll leave it up. The reader notes, from Theodore von Karman:
Scientists discover the world that exists; engineers create the world that never was.
UPDATE: Solar farm in Bavaria (yep, really), IBC Solar AG, Bad Staffelstein:
Apparently Bavaria is the ultimate place for solar photo-voltaic investments. It is not a matter of maximizing electricity production, so much as maximizing subsidies.