This article is an excerpt from an exchange that took place as part of “Science yourself! », organized by CEA and CENTQUATRE-PARIS.
What energies do we need for our applications, and what energies will we still be able to use in the future, given the challenges of energy sobriety, which are more relevant than ever?
Stephane Sarrade : We should reverse the question by first asking ourselves which societal choice we want to make before deciding on the most suitable energy mix for this choice. With two factors to consider. First factor: power
access to energy sources at a price compatible with our finances. This concept of cost is crucial! We have seen this clearly since September 2021 with the unprecedented increase in electricity and gas prices in the European markets and more recently the war in Ukraine, which again caused a very sharp increase in these prices. This war is reminiscent of the first oil shock in 1973 and the subsequent energy crisis. I remember the scavenger hunt, the energy savings, the speed limit on the motorway to 130 km/h: nobody believed it was possible at the time! It was the beginning of energy sobriety. Because sobriety must necessarily be associated with costs when talking about availability of energy sources.
The other factor to consider is environmental impact, which is double. On the one hand, there is climate change, the expected increase of a few degrees, which will have devastating effects. What is required of us is therefore
the decarbonisation of our energy consumption in residential areas, mobility, industry or even agriculture. With the aim of achieving zero net CO emissions2 before 2050. And on the other hand there is conservation of resources.
Although we know what needs to be done to decarbonise the energy system, 50% of the technologies we need do not yet exist. Whether it is about production technologies, conversion, storage, flexibility, smart grids, interconnection between heat networks, electricity networks and gas networks…
Rodolphe Meyer / The Awakener : 85% of the energy used in the world is fossil fuels. In France, electricity is relatively low carbon, but for many purposes we remain a “fossil country” like the others. There is climate change, conservation of resources, but also other environmental problems generated by fossil fuels, such as the degradation of biodiversity, oil spills or air pollution, which kills 40,000 people a year in France. In addition, fossil resources have a cost to individuals and are not mined on our territory. It hurts the trade balance a lot: the money is sent abroad instead of being used to develop activities in France. There are also enormous environmental impacts on the entire chain of extraction and production of these energies. The use of fossil fuels is causing so many problems that we don’t even need to talk about the climate to make people aware of the urgency of getting out of it.
What is the ideal energy transition scenario?
Stephane Sarrade : RTE, our electricity transmission network, released a report at the end of 2021 with scenarios
issues of sobriety and our lifestyle. In France, in 2022 we will use 1600 TWh of energy with a fairly low share of electricity, around 25%. In RTE’s projections for 2050, there is first of all a 40% decrease in our energy consumption and a significant increase in the share of electricity, which will be 55%. The energy transition, as imagined in the RTE scenarios, therefore involves
an increase in carbon-free electricity. When we talk about 930 TWh expected consumption in 2050, it is for a lifestyle that is not very different from ours… With, having said that, some significant changes, such as mobility or individual housing, which should be greatly reduced.
Rodolphe Meyer / The Awakener : Do not confuse two axes,
that of energy efficiency and that of sobriety. In all scenarios aimed at reducing final energy consumption, the use of electricity is increased because it makes it possible to effectively reduce the use of fossil fuels. For example, traveling with thermal cars today requires around 300 TWh of oil per year. If tomorrow we use electric cars for our individual mobility, we will need three times less energy! Energy efficiency means that less energy is used for the same performance. While sobriety is
a change in behaviour, an evolution in our lifestyle. Where we ask ourselves the question of what we really need and whether it is really necessary to use this energy, this object, in terms of the impacts that are generated. Where we adapt our way of life and our needs according to the available energies. While currently it is energy production that adapts to our needs.
How can we manage to build optimistic scenarios for 2050 and at the same time maintain a lifestyle that roughly corresponds to the one we have today?
Stephane Sarrade : RTE’s scenarios are not optimistic or pessimistic, they are factual. There are 6 scenarios with or without nuclear power, with a fairly wide range, ranging from sobriety and changes in society to much more ambitious scenarios, especially about reindustrialization. Because here also another societal choice arises: do we want to live in a country that is completely dependent on other states to access energy sources and/or produce them? Or we do
the choice of reindustrialization ? At present, for example, we buy solar panels in China. In the context of the energy transition, wouldn’t it be more interesting to have mega-factories in Europe to manufacture our panels on site?
Rodolphe Meyer / The Awakener : The energy mix scenarios can shed light on the decisions to be made, but they are not set in stone. They indicate that if we have this or that technology that works, if we make this or that choice, we will have this or that trajectory. And the more we go forward, the more we’ll be able to specify that trajectory as we go.
When we talk about energy transition, ecological transition, we are aiming for a very long-term goal, namely sustainability. But in light of the climate crisis, we must start acting very quickly, all the scenarios are very clear in this area. You don’t have to wait for the perfect, absolutely durable solution. The energy transition is an incredibly complicated project where everything has to be rethought. If we fully activate all the levers, to do wind, offshore wind, solar, nuclear, in terms of deployment, that is extremely ambitious. There are lots of hurdles that we hope to gradually resolve. That’s why you need to start right away, to have as many technologies as possible very quickly.
Stephane Sarrade : We will also have to adjust our two brain hemispheres. If we do a quick and somewhat honest introspection, we still have half the brain of a consumer (car, internet, etc.) and half the brain of a voter who cares about environmental issues. Applying these scenarios will require reconciling these two behaviors.
We also need to be very humble about how we imagine the population’s use in 2050. It is already clear that the way we live today will not be the standard of living in 2050. Personally, I don’t want to live like my grandparents did 50 years ago. Projecting yourself by saying that happiness for future generations will be that they have the same way of life as us in 2050, to me that is already wrong. In 2100 it will be even more false. It is the population in 2050 who will be the prescribers of society’s choices and thus the associated energy systems.