2. Why hydrogen?

Solar energy is emitted in the form of photons. The amount received by the Earth is several tens of thousands of times greater than the energy it consumes... which is considerable, and may reassure us about the state of our resources! These photons can be recovered in two ways:

• or directly via photovoltaic collectors, which convert them directly into electricity;

• or via the production of heat generated in contact with the ground or materials; this thermal energy feeds the atmospheric machine to produce rain (source of hydropower) or wind (source of wind power) and is also recovered via thermal collectors to feed solar water heaters or higher-temperature receivers that transform this energy into electricity via thermodynamic converters (solar power plants).

Of all the possible...