Energy saving: Are data centers really the “digital ogres” of ecology?

In recent years, data centers have improved their performance considerably. While their development is certainly not without consequences in terms of energy consumption, are they still energy chasms?

In 2015, the digital sector consumed around 10% of the world’s energy production, 18% of which was consumed by all data center and the IT servers they host. These figures come from a summary published in 2017 by the “negaWatt” Association, whose objective is to abandon fossil and nuclear energies by 2050.

Data centers, their infrastructure and energy consumption

Data centers are data storage centers—physical places where several thousand central units called servers are gathered. Servers are machines connected to one other, i.e. networked. The objective is to be able to host large volumes of digital data. The Internet connection is essential so that users, often external, can access the data stored on these servers. At the beginning of the digital age, companies had their own internal LAN server. The principle is the same as when we save our data on the hard disk of our own computer. But such a structure, which stores more and more data, requires a substantial budget. Especially since the risks of breakdowns often put companies at risk. Nowadays, backup or data hosting methods have evolved. With the Internet, cloud computing is becoming a trend: “Cloud Computing”.

The Cloud, the system that changed everything

The Cloud can be defined as a virtual storage or hosting system. In reality, it consists in circulating your digital data, from your hard disk, tablet or smartphone to remote storage, grouped in a data center. Your data, and even your software, are then available at any time, wherever you are, provided you have an Internet connection. This makes data management easier for users and companies. Outsourcing IT hosting has naturally become a major trend with the growing volume of data circulating, especially in e-commerce where professional websites are always available without interruption. According to a study released by Cisco, the current storage capacity of data centers will no longer be sufficient by 2021: it should be multiplied by 4. It is in this context that data centers are becoming more and more strategic, but with this growing question about their energy-intensive reputation. Because it is true that it takes a significant amount of energy to keep the machines running all the time and, above all, to cool them efficiently.

If energy consumption is unavoidable, why not recover the heat dissipated from the Data Centers?

In 2015, the French Electricity Union (UFE) indicated that French data centers consumed about 3 TWh. This is almost equivalent to the electricity consumption of the city of Lyon. Half of this electricity consumption is used for cooling and air conditioning in data centers to ensure the security of hosted data. This is a major concern of data center professionals who are striving to reduce the cost of cooling bills by opting for “free cooling” or cooling via fresh air from outside. This is the case, for example, of the offshore Facebook servers installed in Sweden, since the Nordic country has a cold climate.

Exploiting heat dissipation for district heating

Of course, the Joule effect – the generation of heat when an electrical current passes through any conductor – can be used to counter the large expenses incurred in cooling systems. This heat produced can be used as district heating. Several places in France already benefit from this specific use. The Val d’Europe business district, a student residence in Grenoble, and a public swimming pool in Paris are two examples. Although the technology is still quite limited, it represents a significant step forward in offsetting the energy costs associated with data center operations.

Performance gains and the recovery of dissipated heat are all positive points for data centers. Especially since, according to the “négaWatt” Association’s report, other infrastructures are much more energy-intensive than data centers. For example, all the terminals used, namely computers, tablets and smartphones, altogether consume twice the energy used in data centers.

Finally, to further reduce energy consumption in the digital sector, it is important to remember that everyone must play their part by adopting simple everyday habits such as, deleting old emails, especially those with large attachments, or limiting the consumption of streaming videos. In 2017, Le Parisien published a quote from Greenpeace analyst Gary Cook, stating that simply viewing the video of Korean singer PSY, “Gangnam Style”, consumed the equivalent of the annual production of a modest power plant. Indeed, this video has been viewed more than 2.5 billion times worldwide.