Mots clés : #decarbonization #energy #efficiency #economy #ecological transition
In 2019, the Government asked RTE, the electricity transmission network, to do a prospective work to reflect on the energy model of the France by 2050. RTE presented its first results on Monday 25 October. As a reminder, the France has set itself the goal of reaching zero net emissions in 2050 and less than 40% of energy consumption. Fossil fuels now account for 60% of energy consumption in France. Therefore, the challenge is ecological, but it is also of energy origin, regarding our dependence on fossil fuels imported from abroad.
Is it conceivable for us to get out of fossil fuels cleanly and quickly to start our eco-transition?
In the report, the achievement of these objectives goes through 3 main axes: The electrification of uses, the development of renewable energies and low-carbon energies, then the increase in energy efficiency and energy sobriety. The solution might be a mix of the different scenario that the RTE report deal with, and it is legitimate to consider several of them to achieve our objectives. There are two families of scenarios: there are three scenarios with 100% renewable energy and three other scenarios with the construction of new nuclear power plants. Even if RTE does not directly pronounce itself in favour of one scenario rather than another, it defends the energy mix and the renewable energy – nuclear duo for ecological but also economic reasons. RTE concludes by stressing that regardless of the scenario chosen, the urgency to act is the same. The President of the Republic should even make announcements in the coming weeks. It is essential to consult upstream with local elected officials who are at the heart of the ecological transition.
All these scenarios came up with the same conclusion including a security supply and a zero-emission balance in 2050. There are not all possible considering that electricity consumption is going to increase in the coming decades and that the nuclear plants are starting to get cost effective, and we will have to deal with nuclear energy in 2050.
The “M” scenarios do not rely on the construction of new nuclear power plants with a total nuclear phase-out thereafter. The difference between these scenarios is the pace of development of renewable energies and the energies selected. The 100% renewable energy scenario is possible but difficult. In all its scenarios, the means of flexibilities are essential because they are the ones that reduce the effect of the intermittency of renewable energy. They all start with an installed capacity of 1.7 GW of electric vehicles (V2G Vehicle to grid). Indeed, security of supply is fundamental.
The “N” scenarios are based on the construction of new nuclear power plants. The difference between these scenarios is the pace of construction of new reactors. The scenario N03 provides for the construction of new reactors but also the extension of the current power plants. Scenario N also contains a lot of renewable energy. These scenarios are more varied and have the merit of being at the same time more realistic. They highlight nuclear, modular, and decarbonized technologies.
The three main axes that will help to achieve our objectives:
Acting on consumption
The reduction in consumption implies improving energy efficiency but also developing energy sobriety, less energy consumption by taking transport that emits little or no C02 instead of taking the car for short trips or even favouring appointments by videoconference instead of returning to the plane or the car to go directly to the appointment. The development of energy sobriety therefore implies a global change in our lifestyles.
Develop the means of management to maintain the balance between supply and demand:
In all scenarios, it will be necessary to develop the means of control via the management of consumption thanks to digital, interconnections, hydraulic storage, and battery. To ensure this balance, it is also essential to rethink the transmission but also distribution network with significant and planned long-term investments. The need for flexibility is not the same depending on the scenario. Nuclear scenarios imply less flexibility.
Considering the effects of climate change on the electricity system
Temperatures in France are likely to rise to +2.9° between 2041-2070 compared to the period 1976-2005. Heat waves will multiply and be more and more intense but cold waves without wind will also be more numerous in winter. It is indeed climate change and not global warming that awaits us. To cope with this phenomenon, it will be necessary in the coming years to double the pace of investment in the network regardless of the scenario chosen. These investments will be used to adapt the electrical system but also to help the electrical system cope with the high heat that directly affects it.
Development of renewable energies: solar and wind in particular
The report insists on the need for a harmonious development of these energies. A 100% renewable energy scenario is possible but implies an acceleration of the development of renewable energies and their acceptability. This scenario, which involves the rapid closure of power plants, has a significant economic cost. Finally, the report highlights the competitiveness of renewable energies but also the need to develop large parks that allow economies of scale. RTE also calls for the need to maintain public support for both renewable energy and new nuclear reactors that will not arrive before 2035. It also defends the maintenance of a system of regulation of energy prices. On the issue of wind power and renewable energies, the report highlights a space issue especially for the 100% renewable energy scenario but rejects the idea of generalized pressure on the artificialization of soils. This pressure will be mostly localized. It also highlights aesthetic and heritage issues to be taken into consideration. These challenges will be found for small nuclear reactors with the addition of safety issues. On the issue of rare earths, RTE does not identify a risk of voltage but emits points of vigilance especially on metals such as lithium or nickel necessary for batteries. It is therefore essential at the same time to reduce the number of cars but also to reduce the size of the batteries and to promote their recycling as much as possible. For nuclear power, the report does not see a specific issue on uranium supply but draws attention to the issue of untreated or recycled nuclear waste.
Developing low-carbon hydrogen, particularly in certain difficult sectors
Hydrogen may be an attractive solution in replacing the original gas, but there are many uncertainties about the hydrogen economy. Hydrogen makes it possible to decarbonize sectors that are difficult or impossible to electrify economically and technically, such as industry or freight transport. The priority objective is therefore to replace fossil hydrogen with low-carbon hydrogen. For the scenario of the development and use of hydrogen we will in any case have a significant growth in electricity production. The production of hydrogen by electrolysis is flexible and adapts to renewable production. However, this flexibility is possible if hydrogen storage and transport infrastructure is acquired. For hydrogen to be flexible, it is important to develop hydrogen storage and transport infrastructures.
Achieving carbon neutrality by 2050:
To achieve this goal, it is necessary to understand that the electrification of uses must allow us to get out of our dependence on fossil fuels, particularly in transport and industry.
Extending the life of nuclear power plants or replacing them with new generation reactors ready in 2050 only.
According to RTE, the construction of new reactors is economically relevant. The extension of existing plants is a technical but also an economical challenge to avoid the “cliff effect” (Closure of plants at the same time since they were built in the same period and have the same lifespan). This extension appears mandatory because the new generation reactors will enter service at the earliest in 2035.
Whatever the scenario is, the cost of energy will remain stable or at least more stable than in the current system dependent on gas and oil. Only the photovoltaic on small roofs remain more expensive than the new nuclear. RTE estimates the current full cost of the electricity system at €45 billion per year. In 2050, in its report, it oscillates between 59 (scenario N03 with 50% nuclear in 2050) and 80 billion euros (scenario M1, with 100% renewable energy in 2060) annually in total.
On this graph, we note that nuclear costs more than renewables energy. However, the disadvantage of renewable energy is that they participate into the destruction of the landscape (Wind and photovoltaic on the ground). The advantage of new nuclear being that it allows to centralize in one place the electricity produced.
We notice that the higher the share of nuclear power in the chosen scenario, the lower the cost of flexibility is, which costs a lot of money. A scenario that intelligently combines nuclear power and renewable energy seems to me the most desirable.
Which scenario seems to be the most realistic?
The N1 and N2 scenarios seems to me the most interesting because they have a more reasonable cost. N2 scenario would make it possible to keep a reasonable share of nuclear power and to develop renewable energies over the years. Overall, we can achieve the electricity system of carbon neutrality by 2050 at a controllable cost for our country. We need to develop mature renewable energies as quickly as possible before about ten years and we need to extend existing nuclear reactors to maximize our low-carbon production. Finally, the clearest conclusion we can make is that there is urgency, no matter which scenario is chosen.
According to the Figure 1, we can see that the N2 scenario is positioned with 63% renewable energy and 37% old and new nuclear. It will mainly develop solar at 20%, onshore wind at 20% and new nuclear installations at 22%.
According to the Figure 2, the N2 scenario slightly accelerates the deployment rates of terrestrial renewable energies, develops, and connects new marine energies, compensates for the variability of renewable energies by means of adapted flexibilities. It will also weakly reconfigure networks and evolve operational reserves. This scenario will moderately ensure the stability of the electrical system and extend some current reactors up to 60 years. N2 scenarios will greatly accelerate the commissioning of a large number of new reactors between 2035 and 2050 (one pair of reactors every 3 years). According to the Figure 4, from the graph we can see that the N2 scenario by 2060 will mainly invest in nuclear and renewable energies. We also see that the N2 scenario has a more reasonable cost than the other scenarios.