Olmedilla Photovoltaic Park is the largest Solar power production facility. Currently is 250,000sq m. facility with output of 85GwH per year.
We currently consume about 2700000Gw per year.
Which means with current efficiency we would need
2700000/85 * 250,000 = 8,000,000,000 m^2 of space = 3088 square miles
that's of course is a lot of space but... Mojave desert itself is 30,000 square miles.
So even without using more efficient solar cells ( developed every year ) 10% of mojave desert can support the entire US electricity production.
__________________
Человек, который почувствовал ветер перемен, должен построить не щит от ветра, а ветряную мельницу