1. Storing energy: a necessity

We store what we have too much of so that we can use it later when required. From the earliest sedentary civilisations, farmers have stored the excess grain which they have harvested in summer to meet their needs in the winter. The same applies to the energy, which is essential for human beings to live and develop economically. Food is, after all, just a specific form of energy which is essential to them.

Energy needs are currently met either by energy sources (oil, coal, natural gas, etc.) or by energy carriers.

An energy carrier enables energy to be transported continuously from one point to another. This is the case with electricity, which is increasingly used in modern civilisations, and heating networks. Even though an energy carrier can supply energy to an user, an energy source is required...