Solar in the Sahara

The Sahara has a few interesting properties: lots of sun, lots of sand, and lots of empty space. I first came across the idea of large-scale solar development in the Sahara in David MacKay's book Sustainable Energy Without the Hot Air, looking at using it to power Europe.

Now it seems that there's a Japanese-Algerian collaboration trying to use the Sahara as a basis for worldwide power distribution, trying to construct solar cells using the sand of the desert of a base ingredient.

(The Sahara is about 8.6 million square kilometeres... covering around 10% of that with solar panels would produce energy output equivalent to the entire world's current consumption. Add in the storage and distribution challenges of course).