A stiffer, more formal (form, schmform!) way to ask this is:
Is a solar panel field the size of Spain enough to cover the worlds energy needs?
(This assumes that everything in the world runs on electricity. This of course, can be technically true, but we would need much smaller ships and different planes etc.)
There's this Businessinsider article that states that the world energy consumption can be covered by a solar panel area the size of Spain? (Source seems to be TechInsider) 
Since Spain is only 0.335% of total global land area, then, if every country dedicated one third of one percent of their area to solar panels, we would be able to supply the worlds energy, aside from rockets, (according to Elon Musk in 2nd paragraph)
But doing the math told me that:
- a. the world consumes 157,5 PetaWh/year (1.575 × 10^17 Wh)
- b. about 1000 Watt of sunlight hits one square meter,
- c. at 100% efficiency, 157.000.000.000.000 m2 is needed or 157 million km2
- d. but actual average efficiency/effectiveness is 16,6% efficiency so we would need six times that much solar panels or 942 million km2
- e. Even at recent Japanese claims of 26.6% efficiency we would need about 590 million km2
World area 510.million km2 of which land is less than 150 million km2
So, where do I or the article go wrong?
EDIT: sorry to edit so much.
