Computer giant Apple, which has been under attack from environmentalists for its greenhouse gas emissions, has announced it will power its main US data centre, used for its iCloud services, entirely from solar energy by the end of the year.

It plans to invest an unspecified amount in solar generation capacity sourced from SunPower Corp, plus solid oxide fuel cell technology from Bloom Energy.

The fuel cells will supply stored power generated from the sun, when it isn't shining, and use a ceramic powder instead of platinum to produce electricity with greater efficiency than traditional fuel cells.

They operate at extremely high temperatures, typically above 800°C, which improves their electrical efficiency.

Bloom Energy already supplies Google, eBay and Walmart as well as Adobe, Coca-Cola and other household names.

SunPower Corp was the foremost commercial solar installer in the United States last year.

According to Apple's CFO Peter Oppenheimer, the investment will benefit its North Carolina facility, which holds the servers that host its iCloud data services.

The solar farm will provide 84GWh of energy annually, more than sufficient to power the data centre.

This data centre is not the only one used for the iCloud by Apple, but it is the main one.

Greenpeace last month challenged Apple in its report “How Clean is Your Cloud?” that it was not as green as Facebook and Google.

Data centres contain thousands of computers that store and manage the world's rapidly growing accumulation of data for consumption at a moment’s notice. They consume a tremendous amount of electricity and are responsible for around 2% of global GHG emissions.

But Greenpeace says that most IT companies are rapidly expanding without considering how their choice of energy could affect climate change.

Greenpeace said that Yahoo and Google both continue to lead the sector in prioritising renewable energy to power their cloud expansion.

It accused Amazon, Apple and Microsoft of rapidly expanding without adequate regard to the source of electricity, and of relying heavily on dirty energy.

It applauded Facebook for committing to power its platform with renewable energy, and Akamai, responsible for carrying much internet traffic, for being the first IT company to begin reporting its carbon intensity under the new Carbon Utilization Effectiveness (CUE) standard.

In response, two weeks ago, Microsoft promised that it would go carbon neutral after July. Its chief operating officer Kevin Turner said that it would use carbon offsetting and improved energy efficiency.

Greenpeace criticised Microsoft however, because carbon offsetting still allows it “to keep building data centres that rely on coal, such as its new investments in Virginia and Wyoming".

Apple, however, appear to have listened to Greenpeace's advice.

Story: David Thorpe, News Editor