The move is part of Apple’s goal of having its data centres run on renewable energy. There is a lot of sun in Nevada and not much else. The new solar farm will provide power to Sierra Pacific Power electric grid that serves Apple's data centre and when completed will generate about hours 43.5 million kilowatt of clean energy a year.
Apple already runs its largest data centre in the U.S. on solar power. The centre in Maiden, North Carolina produces 167 million kilowatt hours, the power equivalent of 17,600 homes for one year, from a 100-acre solar farm and fuel cell. Ironically the North Carolina site was a draw card for Apple because of its cheap coal power energy. It is still not clear what Apple wants all its data centres for, but at least we know that Fruity Co is not killing dinosaurs to power them.