We cannot do without oil but we may, on the other hand, stop using the atom. We should never lose sight of the fact that there are several means of generating electricity, using among others coal, gas, oil, biomass, solar radiation and wind. At the scale of a whole country these generating technologies are generally combined to form an energy mix, which may or may not include nuclear power, much as it may or may not include thermal coal or gas, wind or solar.

The various technologies are both competitors and complementary. Conventionally a distinction is made between baseload generating technologies, coal-fired power stations for example, which operate round the clock all year long, and peak generating technologies, such as oil-fired power plants, which only operate at times of peak demand. With a finer mesh, further categories can be distinguished, of semi-baseload and extreme-peak generation. The overall idea is to classify production resources in such a way that the ones with high fixed costs and low variable costs are used for as many hours a year as possible, while on the other hand those with low fixed costs and high variable costs are only used for a few hours a year.