Saint-Ouen-l'Aumône (France) (AFP)

Without a digital safe, it is impossible to send an email or use an application.

"Data centers" or data centers have become essential in our daily life and are proliferating in Ile-de-France, where their "energy-intensive" presence arouses contestation.

Behind the small screen of a phone hides "a warehouse in which we store tens or hundreds of thousands of computers that operate 24 hours a day and are part of the cloud", summarizes Arnaud de Bermingham, president of Scaleway, a subsidiary hosting company Iliad (Free).

The group has four data centers in France, all located in Ile-de-France.

These infrastructures, which have nothing virtual, are settling in the Ile-de-France region because "they need great electrical power, optical fibers and land away from areas of natural risk", explains Cécile Diguet, town planner at the Paris Region Institute.

In 2021, Ile-de-France has 124 "data centers" out of the 138 referenced in the region.

And Seine-Saint-Denis constitutes the first concentration of data storage in Europe, because with its industrial past the department has "large plots of wasteland at low cost", specifies Ms. Diguet.

Interxion, one of the world leaders, has offered the Airbus Helicopters plant in La Courneuve to set up "the largest data center in France on seven hectares", according to its director Fabrice Coquio.

In September, the American group will inaugurate the first building of the mega-complex, an investment "of more than one billion euros", specifies Mr. Coquio, who had installed his first center in Aubervilliers in 2000.

Its clients: Facebook, Google, Tinder ... "All the major players in American tech, telecommunications, but also French groups and institutions".

The increase in digital consumption, especially with teleworking, the development of connected objects and artificial intelligence, requires more storage.

Photograph of July 9, 2021 of the Scaleway "data center" or data center in Saint-Ouen-l'Aumône ALAIN JOCARD AFP

"In the 19th century, we built stations, in the 20th century highways and airports, in the 21st century, we built cable networks and data centers," analyzes the boss of Interxion France.

And the constraints to settle "are light", estimates Cécile Diguet, director of a study on "data centers" in Ile-de-France, a region which is approaching saturation in terms of electricity supply and land availability.

These digital safes can have effects "on health", further estimates the town planner who points to "the risks associated with the storage of fuel oil" intended for generators in the event of a power failure, electromagnetic waves or the noise of air conditioners.

In 2015, two residents of La Courneuve and the environmental association URBACTION'93 obtained the cancellation of the prefectural decree which authorized the operation of the Interxion "data center" in a residential area.

The group ended up getting its sesame after being upgraded.

But voices are still rising to contest its mega center under construction along the A86 in La Courneuve, where PCF mayor Gilles Poux would have preferred to see a school and housing set up.

- Amazon failed -

In Essonne, an agglomeration won a first step against the construction of the Amazon "data center" in Brétigny-sur-Orge.

The regional prefecture refused approval in April but the digital giant filed a graceful appeal.

In its decree, the prefecture notes "that no solution for the recovery of the fatal heat (released) produced by the project (...) is proposed".

Photograph of July 9, 2021 of the Scaleway "data center" or data center in Saint-Ouen-l'Aumône ALAIN JOCARD AFP

"I am not against data centers", assures AFP Eric Braive, president of Cœur d'Essonne which brings together 21 municipalities.

"But we are saying to Amazon: + you are the largest company in the world, you cannot build an average data center. It must be as innovative as possible and contribute to the energy bill +".

This future center "is not attached to the heating of a swimming pool or of social housing, it is an energy-intensive product which loses this energy", regrets the elected official.

Amazon wants to build its center near an industrial building belonging to it, but also next to an organic farm which "produces 130 tonnes of vegetables per season," recalls Mr. Braive.

The elected official hoped that the arrival of Amazon would provide jobs.

But the project is only equivalent to "100 or 200 jobs maximum".

Contacted by AFP, Amazon said it did not have a spokesperson available.

"A data center is very energy intensive", concedes the president of Scaleway.

For its center in Saint-Ouen-l'Aumône (Val-d'Oise), the electricity bill amounts to one million euros per month.

As far as the eye can see: rows of computers, servers or routers connected to optical fibers.

But this "data center" does not use air conditioning and "consumes between 40 and 50% less energy", by using an "ancestral" system called "adiabatic", welcomes Arnaud de Bermingham.

The heat given off by the machines, which is permanently overheated, is mixed with the outside air and reused to cool the computers.

If it is impossible to do without "data centers", "virtuous technologies are possible", assures the company manager.

© 2021 AFP