Greenpeace International today reevaluated its rating of Apple’s iCloud power sourcing following announcements from Apple that it would add more solar power at its North Carolina-based data center and source 100 percent of its energy for all of its data centers from renewable sources. While Greenpeace revised its grading of Apple on the news, it still wants more clarity into how Apple plans to meet the ambitious goals.

When Greenpeace released its report: “How Clean is Your Cloud?” earlier this year it gave Apple three “D” grades for its Energy Transparency, Energy Efficiency & GHG Mitigation and Renewables & Advocacy, and an “F” for its Infrastructure Siting policies related to its data center strategies. Under the revision, Energy Efficiency & GHG Mitigation and Renewables & Advocacy were upgraded to “C”, while Infrastructure siting was upgraded to a “D”. The revisions, the only one that Greenpeace has thus far issued, place Apple ahead of some competitors including Microsoft and Amazon.com, but still behind Google, Dell and Yahoo.

“Right now, in data centers, Apple’s made a  great claim. It’s a bold vision that they want to be 100 precent renewable, but its more. They need to show the details,” Greenpeace IT analyst Gary Cook. “We’re giving them credit for the new commitment but we need to see more details about how they’re doing it,” he said.

The revision came largely as a result of Apple announcing that it is doubling the solar photovoltaic array at its Maiden, N.C. data center, that it would make all its data centers, which include one in Newark, Cal., one in Prineville, Ore., still being built, coal free, and that it’s newest data center will be in sun and solar-rich Nevada.

However, just how the company is doing it, isn’t so clear, according to Cook. For instance because of regulatory filings in North Caroline, Greenpeace is concerned that Apple may be selling the energy directly to Duke Energy, the state’s only utility and one that primarily uses coal. Greenpeace wants to know that Apple is using the energy produced by the 40 megawatts of PV and the 5 megawatts of fuel cells its installing at the North Carolina site.

Greenpeace also is concerned about what direction Apple CEO Tim Cook will take the company in terms of its environmental efforts. For instance, the company reacted quickly to allegations of labor issues in China. But Apple’s decision to back out of the voluntary EPEAT standards, which were designed to make sure electronics are environmentally friendly concerned Cook. Still, Greenpeace has put a lot of pressure on Apple that has helped deliver change.