Energies of the future: what energy mix to achieve carbon neutrality by 2050?
In 2019, France set itself the target of achieving carbon neutrality by 2050. If we are going to meet this climate commitment, we need to speed up the country’s decarbonisation and redefine the energy system, two-thirds of which still depends on fossil fuels. At a time when the country is launching consultations on the future French Strategy on Energy and Climate, which will serve as the national roadmap for achieving carbon neutrality in 2050 and adapting our society to the impacts of climate change, three projections performed by ADEME (the French agency for ecological transition), RTE (the French transmission system operator) and NégaWatt (a think tank) question the energies of our future.
The NégaWatt scenario: low-consumption behaviours, efficiency, renewables
NégaWatt set the ball rolling in October 2021, with the publication of its fifth energy transition scenario for France 2022-2050. The vision of the think tank, which was founded in 2001, is based on three fundamental principles:
• Reducing needs through low consumption in individual and collectives uses of energy
• Energy efficiency to reduce the amount of energy required to fulfil the same need
• Prioritising renewables, which can progressively replace fossil and nuclear energies
According to this scenario, oil, fossil gas and coal will have virtually vanished from the French energy landscape by 2050, and the last nuclear reactor will have closed in 2045. Primary energy consumption will have fallen two-thirds by 2050, and the production of renewable energies will have tripled, driven mostly by the development of both onshore and offshore wind power.
New elements in this scenario compared to the previous version (published in 2017) relate to the inclusion of imported emissions and available resources: greenhouse gas emissions generated by the manufacture abroad of goods imported into France are factored in and the scenario is based on possible changes in the consumption and production of materials (steel, concrete, copper, plastics, lithium, etc.).
RTE scenarios: increased share of electricity in consumption and strong growth in renewables
At around the same time, RTE presented the key conclusion of its study, Energy Pathways to 2050. The study sets out six electricity mix scenarios, all of which make it possible to achieve carbon neutrality by 2050. They share several common points: a decrease in final energy consumption, an increase in the share of electricity and a strong growth of renewables in electricity production.
As with the NégaWatt scenario, the RTE study considers the effects of energy efficiency and frugal behaviour on the level of consumption. Energy efficiency could lead to a 200 TWh saving in consumption thanks to proactive public policies to renovate buildings, the gradual reduction of energy consumption in capital goods and the electrification of certain uses, such as those related to transport. At the same time, profound changes in lifestyles towards greater energy frugality could save an additional 90 TWh. For example, this means voluntarily limiting heating and the use of hot water, increasing remote working to limit office space, reducing the average speed of traffic and the size of vehicles, and reducing the needs of certain industries (e.g. the food industry, in the context of less processed food).
Renewable energies feature in all the scenarios envisaged; they will account for between 50% and 100% of the French energy mix by 2050, so a significant expansion of renewables is essential. On a technological level, the greater the proportion of renewables in a given scenario, the greater the storage capacities and network resizing will have to be. The fluctuating nature of renewable production has to be offset by flexibility: new storage capacities need to be developed (hydrogen, batteries); cross-border exchanges will be crucially important for sharing renewable production at European level; and digital technology will allow consumption management to be optimised.
Three scenarios predict a 100% renewables system combine with a more or less progressive phasing-out of existing nuclear power. In three other scenarios, which combine renewables with nuclear power, envisage the construction of new-generation EPR reactors. Even so, two of these scenarios give a high priority of renewables, which account for over two-thirds of total production. Only one scenario, the most nuclear-dependent, assumes parity between production from nuclear plants and renewables.
ADEME’s 2050 Transition(s) scenarios: low-consumption behaviours, shared governance, technologies and innovation
One month later, in November 2021, it was ADEME’s turn to unveil Transition(s) 2050: 4 scenarios for achieving carbon neutrality in 2050. Two scenarios, “Frugal generation” and “Territorial cooperation”, are based on a lifestyle transformation and more shared governance. The other two scenarios, “Green technologies” and “Restoration gamble”, focus rather on new technologies and innovation.
The adoption of frugal behaviours is one of the key issues addressed in these scenarios. Those based on a limited modification of current lifestyles have a delayed impact on emissions: they put back the date for achieving carbon neutrality by five years. At issue are uncertainties over the time needed for certain CO2 capture technologies (essential in the technology-based scenarios) to reach maturity. But the trajectory matters as much as the 2050 target date: only the first two scenarios hit the 2030 milestones, corresponding to the targets set by Europe. On the other hand, the scenarios based on frugal behaviours raise the question of their social acceptability.
As far as the energy mix is concerned, the share of electricity increases in all the scenarios (although total electricity production does not necessarily increase in absolute terms). Fossil energies almost completely disappear, and there is a sharp rise in off-grid renewables (e.g. geothermal). Gas, which is necessary for certain uses, has a place in all the scenarios, in the form of biogas. There is also a big increase in liquid fuels, particularly in the technology-based scenarios, where biomass is used both for energy purposes and as a biological carbon sink.
What do we learn from all these studies and scenarios? They all highlight the need to reduce our final energy consumption, increase the share of electricity in the energy mix and strongly develop renewable energies. On the other hand, the possible trajectories are very varied and we will need to find the one that can reconcile the right use of technology (to improve energy efficiency, for example), social acceptability and a rapid decrease in emissions. We will probably have to call on all the levers identified in the scenarios: changes in lifestyles, relocation of production that currently emits large amounts of energy abroad, optimisation of uses through more sharing and greater efficiency, and technological progress. On this last point, in particular, many hopes are resting on a green hydrogen revolution, especially in industry and heavy mobility. As it becomes a tool for storing the energy produced by renewables, hydrogen would make it possible to optimise the production of these intermittent energies and the land used to produce them. However, this will require an improvement in the efficiency of hydrogen production as well as a readiness to invest, as this emerging technology remains a costly one.