Amsterdam based data center operator Interxion is building a new European data center for cloud service operator Salesforce in France.

The data center is one of three planned for Europe by Salesforce, with facilities for the UK and Germany also promised. A spokesman for Salesforce would not divulge details of the location of the new site or the capacity. Interxion says the site will be powered by renewable sources, but experts have cast doubt on this claim.

The UK-based data center is planned for autumn 2014, with the French and German sites to follow at unspecified dates in 2015. The data center building strategy is to cover Europe’s three biggest markets as the demand for Salesforce’s cloud services continues to rise, according to the software vendor.

According to Interxion the French data center will be powered by renewable energy sources. However, with 85% of France’s electricity generated by nuclear power, according to Roseau de Transport de electricite (RTE), that could limit the options for the siting of the facility.

Analyst Clive Longbottom, senior researcher at Quocirca, cast doubt on the possibility of a sustainable data center in France.

“Overall, the statement is 100% greenwash - and should be treated as such,” said Longbottom.

“The only way that you can guarantee 100% sustainable power is to have a system that is self-contained and off-grid; something that I would not recommend for any data center, which at the very least needs to be on-grid for availability purposes,” said Longbottom.

The ‘sustainability’ claim, he said, is likely to be a case of Salesforce paying its bills to a generating company that has a stated aim of fulfilling the power on its contracts through sustainable means – but which include nuclear power in its options. “Most of these utility companies only have it as a stated aim - they cannot fulfil these requirements at the moment,” said Longbottom.

Salesforce recently unveiled a new French headquarters in Paris, the Digital Transformation Hub.

"Interxion's state of the art data centre will deliver outstanding connectivity and will offer a highly resilient facility for salesforce.com's growing customer base in France and Europe," said Fabrice Coquio, MD of Interxion, France.