Op-ed articles

The relationship between digital technology and energy

Françoise Berthoud
Françoise BerthoudDirector of EcoInfo (CNRS)

"In a world where every sector increasingly uses digital technology at every level and in an ever-growing number of processes, it is very difficult to evaluate total energy consumption."

The Digital Sector Is Energy-Intensive

Digital infrastructure, equipment and applications now account for a significant and rapidly growing portion of global energy consumption. Françoise Berthoud, Director of EcoInfo, a branch of the French National Center for Scientific Research (CNRS), reviews this trend and explores ways of controlling it.

In a world where every sector from housing to transportation, manufacturing and sales increasingly uses digital technology at every level and in an ever-growing number of processes, it is very difficult to evaluate total energy consumption. To be clear, we are talking about energy, not just electricityForm of energy resulting from the movement of charged particles (electrons) through a conductor.... This includes all the direct and indirect impacts of the activities associated with the extraction of the metals necessary for manufacturing equipment to the energy consumed by the giant data centers and routers that are needed to run the internet.

In terms of energy, the digital sector accounts for 3% to 4% of all consumption worldwide. But if the scope is narrowed to electricity, the figure rises to between 6% to 10%, depending on the study.

Digital technologies’ energy needs can essentially be divided into three parts: one larger part for terminal equipment including computers, telephones and other kinds of instruments, one part for data centers, and the smallest part for networks. But don’t be fooled by this last segment. Networks are not passive, like a gas pipelinePipeline used to transport gas over a long distance, either on land or on the seabed.. They include very active elements that underpin a number of systems (WiFi, GSM, etc.) and information flows. These consume a lot of energy and that amount is only increasing. Over 60% of consumption attributed to networks is from streaming and the ever-growing need for bandwidth is enormous. As everyone knows, we are watching more and more videos online.

Admittedly, there are also factors that contribute to a slowdown in consumption. It is possible that demand for smartphones and laptops has reached a plateau. Equipment is increasingly efficient and standards are tightening. Both companies and individuals want to reduce their spending on energy. But a steady stream of new connected objects is hitting the market and the digital sector has often experienced a rebound effect, well known among energy experts, whereby efficiency gains in equipment and processes are almost instantly offset by demand in new areas. A good example of this is the emergence of energy-saving light bulbs pushing consumers to buy more powerful light fixtures.

How to Reduce Consumption

The heatIn the field of statistical thermodynamics today, heat refers to the transfer of the thermal agitation of the particles making up matter... generated by data centers has inspired a series of ideas. The first is to reduce the amount of energy used to cool servers. This can be done by using more outside air or geothermalDescribes the technology used to tap subsurface heat to produce energy... cooling to lower temperature without relying too heavily on air conditioning. The second option is to capture the heat produced by servers to heat buildings. There are a lot of ideas and trials underway but none that offer particularly convincing results.

Another option is to collectively engage in more “reasonable” behavior. The primary lever is to lengthen the life-span of equipment. On average, smartphones are discarded every two years. Doubling this time frame would represent significant progress. We are also still building oversized facilities to prepare for spikes in demand that may occur one day.

There is also an even more fundamental problem that goes beyond the behavior of individuals. I know I am going against current trends, but maybe we could think outside the box a little and stop making everything digital! There is a big push to integrate digital technology across the board, in both public and private services. If decision-makers make digital technology the bedrock of all administration, health, food, education, tourism, distribution and manufacturing systems, our societies will be weakened and less resilient. In the event of a structural problem, many things could collapse very quickly. There are numerous studies about hacking and system security but I have seen very few exploring the question of the long-term sustainabilitySustainability indicates a state that is sustainable or reasonably manageable over the long term. of these systems.

For example, there is uncertainty regarding production of the rare earth metals necessary for the digital sector. The pollution associated with the extraction of these metals, the impacts on water and the consequences of local conflicts have not yet been properly analyzed. Without being overly dramatic, these are issues that must be considered.


Françoise Berthoud is Director of EcoInfo (CNRS) and a computer scientist at Gricad, a research unit at Grenoble Alpes Recherche, which is involved in high performance computing and data (CNRS/Université Grenoble-Alpes/Grenoble INP).

Remi Martial
Rémi MartialVice-Chairman, Digital Affairs of Chartres Métropole

"The sudden emergence of digital technologies in civic life has led to the concept of the “smart city”. The primary objective of smart cities is to provide services to inhabitants at a lower cost."

Smart Cities and Smart Villages: The Digital Revolution Outside Big Cities

The digital revolution is taking hold in a growing number of public service departments in both urban and rural communities. Many of the applications of digital technology have direct impacts in terms of energy savings. Rémi Martial, Vice-Chairman, Digital Affairs of Chartres Métropole, presents some guidelines for realistic digital development.

The sudden emergence of digital technologies in civic life has led to the concept of the “smart city”. The primary objective of smart cities is to provide services to inhabitants at a lower cost, meaning a lower monetary cost in general and a lower energy cost in particular. It is also important to remember that smart city concepts must be applied even outside urban areas. Even though three-quarters of the world’s population is expected to live in large metropolitan areas by 2050, it is vital that we prevent the formation of digital divides. To this end, France has introduced a number of initiatives to promote the “smart village”.

The need to reduce costs requires rethinking services to bring them as closely in line with demand as possible, meaning just-in-time systems in a number of areas. For example, take household waste collection. In France, waste is disposed of in large containers, often in the ground. Traditionally, there is a set route for waste to be collected from these sites regardless of whether containers are full or not. Sensors could be installed to measure how full the containers are and establish a more logical pickup route. This would result in significant fuelFuel is any solid, liquid or gaseous substance or material that can be combined with an oxidant... economy, not to mention other impacts on areas including personnel and equipment management, and emissions.

This idea of closely matching supply to demand could be widely applied across all networks in general, as seen with the French powerIn physics, power is the amount of energy supplied by a system per unit time. In simpler terms, power can be viewed as energy output... grid and its Linky smart meters. By learning more about how inhabitants and communities consume, we will be able to reduce spikes in use that drive the construction of excess capacity.

Benchmarking, Experimentation and Pragmatism

Implementing intelligent solutions in rural areas needs to avoid certain pitfalls.

Solutions cannot be imposed top-down across all regions. Each community has its own specificities and limitations. Leaders have to benchmark solutions implemented elsewhere and pick the best option. They must be pragmatic.

They must also be ready to experiment. In Chartres, we concentrated services on two streets located in a very busy and touristy part of town to study their required capacity and potential coordination. We looked at street lighting, smart sprinkler systems, parking management, electric vehicle charging stations and waste collection to determine the best data collection and processing methods.

Saint-Sulpice-la-Forêt, a smart village in Brittany, France, is also a good example. They carried out an experiment on connecting up municipal buildings, including the socio-cultural center, the multi-purpose room, the school and the rec center. Each location is now equipped with sensors that make up a network to monitor energy consumption. Over three years, the village has reduced its spending on electricityForm of energy resulting from the movement of charged particles (electrons) through a conductor... by 20%.

Experimentation helps avoid falling for gadgets. For example, the most effective way of reducing the energy use of street lighting is to install LEDs, which are more efficient. We are currently installing this type of lamp in 66 urban and rural communities in the Chartres region with the goal of reducing consumption by up to 40%. We aim to optimize costs while at the same time providing high-quality service with varying light intensity depending on time of day and type of street. We have to keep sight of the realities of every situation.

Without going too far into complex financial considerations, I’m a big believer in the Pareto principle: 20% cause for 80% effect. We need to make smarter investments to meet peoples’ real needs at a reasonable operating cost.

Lastly, something obvious but very important: we can implement the most sophisticated digital services in the world but if there is no high-capacity network (fiber, 4G or 5G), the outcome will be a digital divide that communities feel more strongly every day.


Rémi Martial is an economics professor, advisor to the Eure-et-Loir Department in France and Vice-Chairman, Digital Affairs of Chartres Métropole. He is also the mayor of Lèves, a town with 5,900 inhabitants in the heart of the Chartres region.

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