Global energy production reaches 10 billion tonnes of oil equivalent (toe) each year. It is provided mainly by oil, gas and coal, in a very unequal way at the level of the planet. If rich countries waste, many developing and highly populated countries have a legitimate tendency to massively increase their consumption in the decades to come. Energy scenarios predict a 50 to 300% increase in global energy production by 2050. It is already clear that such an increase cannot be achieved on the current model, based on fossil fuels. , whose reserves are limited, and whose use leads to massive CO2 emissions responsible for large-scale climate change.
The development of new energy sources is essential today, whatever efforts we may make to control demand. These alternative sources are well known and relatively well quantified. Nuclear power appears to be the only source that is readily available on a large scale, but requires a significant mobilization of capital and public acceptance. Solar energy is an important source, but its implementation remains extremely expensive and complex. However, it is already competitive in areas lacking electricity networks. Wind energy represents a limited source and will probably not be able to exceed 10% of electricity production, and always intermittently and randomly. Biomass is an interesting path, but difficult to develop on a large scale. The other sources (geothermal energy, waves, tides, etc.) seem incapable of meeting strong demand. The storage of energy (notably hydrogen) is far from being mastered. It represents a significant technological challenge, and could make intermittent energies more interesting in the future. Finally, thermonuclear fusion represents a massive source, but may not be available before the end of the century.
If the development of electro-nuclear at the global level is undoubtedly the fastest way to fight against the greenhouse effect, this will by no means be sufficient. The energy and climate challenge we are facing requires the implementation of the capture of CO2 emitted by power plants using fossil fuels and a sustained development of renewable energies. Alternatives to fossil fuels have their own drawbacks, but it is not certain that we still have a choice ”
Sylvain David has been a CNRS Research Fellow since 1999 at the Institut de Physique Nucléaire d'Orsay