Like where? And for a minute assume you are in New York city and covering central park with solar panels is not an option. That is the situation in most of West Europe.
Bullshit.
France : 116 people/km²
New York City : 10800 people/km²
You should rewind a few posts more and then you'll read that those rooftops are way too small to fit enough solar panels to meet that demand. I'll admit it might be hard to imagine for people who aren't used to really densely populated countries.
Nope. it works:
There are, in france 6 billion m² of roofs for 67 million people, and 600 billion kWh demand/Y.
That means 85m² of roof per people, for 8500 kWh/y, which means 105kWh/m²/y electrical. At 15% efficiency, that means 702kWh/m²/y of insolation, which is roughly 1/2 to 1/3 what France gets on roofs:
http://sycomoreen.free.fr/imgs/energie_solaire_france.GIFCovering (the best) half of the roofs woud be much more than enough to meet that demand, but with a seasonal time shift.
So yes it's possible to extract enough energy, but it would need a year scale storage to replace completely fossil electricity including nuclear. That seasonal scale storage wil not happen before very long.
Still, it coud replace on the long run roughly half of fossils just by the simple measure of making PV mandatory on roof renovation.
source :
http://forums.futura-sciences.com/environnement-developpement-durable-ecologie/428704-surface-toiture-france.htmlSome more details on electricity in France:
France has 85% of nuclear electricity, and more than half of the homes are heating with electricity, and badly insulated, for a country with a big part in a quite cold climate.
This is total nonsense, so roughly a third of electricity could be spared by a more efficient heating method, insulation, etc, requiring much less solar in the first place.
Politics want to keep the very high nuclear ratio despite the enormous risks, double cost, and unsolved long term storage. Why you ask? To be able to maintain bombs to nuke the world. Utter nonsense.