An important problem is the fog in the winter months. The nights are longer than in summer and the ground cools off. Moisture condenses and fog develops. The Swiss plateau is special that it is essentially a wide valley about 60 miles wide and 200 miles long. The Rhine and the Rhone rivers leave Switzerland through constrictions. So the cold air tends to stay. During the day the sun warms the clear air above the fog such that a temperature inversion manifests itself. Such a situation can be very stable for weeks. Sometimes it even snows slightly under the fog cover. The Swiss living in the plateau complain about the depressing dark and gray weather and try to flee as often as they can by going up somewhere, sometimes the next hill is enough if the fog cover is not very high. Some cities are more affected than others, for example Zurich, Lucerne and Aarau can have months of fog some years.
Google sea of fog switzerland to get some pictures. These are beautiful.
Maine doesn't exactly have usable sunlight, really, ever, between November and March. How Europeans don't freeze to death and go stark raving mad in the dark and cold when they are farther north than our Acadian Nilfheim always leaves me goggling at the wonders of the Gulf Stream.
> How Europeans don't freeze to death and go stark raving mad in the dark and cold when they are farther north than our Acadian Nilfheim always leaves me goggling at the wonders of the Gulf Stream.
You win my certificate of accomplishment for best written description of a feeling that I've read so far this year.
The mountains are more of a problem. There is a famous Swiss village that only gets a few hours of sun in the summer because the prominence of the mountains around it is so high.
I was in the Aosta valley (on the Italian side of the Swiss border, surrounded by the highest mountains in Europe) a few weeks ago in the middle of the winter.
In short: yes there are only about 9-10 hours of daylight but it can get very bright when the sun comes out over the mountains for 3-4 hours. They also grow wine on the south facing parts of the mountains (which requires plenty of sun). And you have to consider that mountains often have clouds/rainy weather.
Another thing to consider is the peaks of the mountains are often above the cloud layers. You can get a sun burn in the middle of the winter in Switzerland quite easily. Just because it's north of most of the US, doesn't mean solar is uneconomical.
So yes, it's not optimal but there's plenty of light. And people do put solar on their roofs there and it apparently makes economical sense to them.
The population density map of Switzerland and the elevation map of Switzerland look like inverses of each other. The famous Swiss villages don’t have many people in them compared to the cities, so the situation you describe, while real, isn’t important.
In the denser parts of Switzerland, apartments are very common. I don’t see how solar works when people are living in a 5 story building. I couldn't see solar working that well where I lived in Lausanne, for example, at least on a person housed/energy unit basis.
Five floors probably isn’t too bad, thought of course that depends entirely on how many people in each apartment and how large they are — e.g. one person in a 50 m² place, divided by five floors, with 20% efficient panels, 25% duty cycle for night/latitude, still implies 500 W, compared to the average electricity consumption in Switzerland of about 900 W per person. It’s not everything but it’s also a pretty impressively large number.
(Something I only found out by looking up Swiss energy consumption: apparently Switzerland produces just over half of its current electricity from hydro power, which makes sense considering the terrain).
Maybe the problem isn't necessarily latitude, but light intensity. Any info on that? It's great that countries here and there are considering alternate options.
There could be a problem with a roof getting covered with snow. Sometimes Alpine pitched roofs have raised strips to stop snow all sliding off at once, you would lose that if it had PV panels on it.
Google sea of fog switzerland to get some pictures. These are beautiful.