Abstract
When speaking of quantification of the efficiency of a system, we mean the calculation of its thermodynamic efficiency, defined as the mathematical ratio between the input energy, i.e. the energy entering the considered system (in any of its forms: electric, chemical, thermal …), and the output energy (once more, in any of its forms), expressed with a pure number (between 0 and 1) or as percentage. The quantification of the efficiency is not a simple operation because it implies a very precise control of the energy flows that cross the boundary of the analysed system, but it is always useful as it is associated to the goodness of the energy transformations that occur inside that system.