There's an Apple data center near me. They feed the hot water into the district heating system and use wind for electricity.

Even if it's environmentally neutral, it's still a ressource hog. Other businesses who want to switch to electricity are currently put on hold, because the data centers are maxing out the grid capacity. I guess it's a luxury problem, but they're causing delays for other businesses in going green, and all only for the purpose of storing iPhone messages and family pictures.

They have about a dozen employees. I think it's mainly security. This has received some criticism because they originally pitched the idea with thousands of new jobs.

So overall, even in a best case scenario it's waste of renewable energy and area which doesn't create any income.