Something doesn't quite add up in the article's numbers:
Area of the solar farm is said to be 610 km², so 61*10⁷ m² containing 7 million solar panels.
That would be an average area of 87 m² per panel, while a standard panel itself covers ~2m².
Lot's of empty space, I would say... Seems like someone found a way to blow up some numbers so it sounds more impressive...
Also: 7 million panels to supply enough power for 5 million households? I don't think so, even in rural China...