Apple’s sapphire plant project in Arizona didn’t work out, so Apple is investing another $2 billion to convert the facility into a massive data center, the Wall Street Journal’s Daisuke Wakabayashi reports (paywall):

The company plans to employ 150 full-time Apple staff at the Mesa, Arizona, facility, which will serve as a command center for its global network of data centers. In addition to the investment for the data center, Apple plans to build a solar farm capable of producing 70-megawatts of energy to power the facility.

For context of what a 70-megawatt solar facility entails, one Arizona solar plant, Solana, says its output is 280 megawatts, supplying some 70,000 houses with clean energy. Apple boasts that it is “the only company in our industry whose data centers are powered by 100% renewable energy.”

The announcement comes after Apple’s sapphire partner, GT Advanced Technologies, filed for bankruptcy last year. The facility was to “produce 30 times as much sapphire as any other plant in the world,” Wakabayashi wrote last year (paywall). At the time, Apple was already consuming “one-fourth of the world’s supply of sapphire to cover the iPhone’s camera lens and fingerprint reader.”

Meanwhile, the sapphire question still needs an answer. The Apple Watch is set to go on sale in April, and certain models include sapphire screens. Apple had also reportedly intended to start making iPhones with sapphire displays. As long-time Apple watcher John Gruber asks today, “So does this mean we aren’t getting sapphire iPhone displays, or that Apple is going to procure them elsewhere?”