After showing more journalists around its solar-powered North Carolina data center (where it is building a third solar farm), Apple says that its new focus for renewable energy is its supply chain. The Guardian reports that the sapphire factory in Arizona forms part of this initiative.

The company is also moving to install solar and geothermal power at a plant in Mesa, Arizona that has been manufacturing sapphire glass. Apple would not directly comment on the Arizona factory but the state’s governor, Jan Brewer, has publicly praised the company’s decision to relocate there and to use solar and geothermal in manufacturing.

Apple’s VP of environmental initiatives Lisa Jackson said that the company is conscious that its supply chain cannot claim the same green credentials as Apple itself … 

We know that our customers expect us to do the right thing […]

We are aware that almost 70% of our carbon footprint is in our supply chain. We are actively working on the facilities that we have here in the United States.

Apple has long been criticized for using suppliers who rely on dirty energy and pollute the environment. While the current initiative will be welcomed, it is notable that Apple is so far referring only to manufacturing facilities within the USA.

Apple’s corporate renewables record is, however, viewed as exemplary – even by former critics like Greenpeace.

“They are the gold standard in the state right now,” said David Pomerantz, a senior Greenpeace campaigner. “There are a lot of data centers in North Carolina and definitely none has moved as aggressively as Apple has to power with renewable energy,” he said.

Lisa Jackson said back in April that 94 percent of its data centers are corporate campuses are now powered by renewable energy, as are 120 of its U.S. stores.