A method for generating energy by nuclear reactions between hydrogen and a transition metal, said method comprising the steps of: - prearranging a primary material that comprises said transition metal; - bringing and keeping said hydrogen into/in contact with said primary material; - heating said primary material up to an initial temperature (T 1) higher than a predetermined critical temperature; - producing an impulse in said primary material, in order to cause a generation of H- ions starting from said hydrogen, and to cause capture reactions (150,151) of said H - ions by said primary material thus causing a generation of a thermal energy (q); - removing a thermal power deriving from said generated thermal energy (q), while maintaining the temperature of said primary material above said critical temperature, characterised in that a step is provided of generating further H-ions that are available for said capture reactions (150,151), such that the concentration of said H- ions changes from a first concentration value to a second concentration value in said hydrogen which is in contact with said primary material, and such that the rate of said capture reactions (150,151) increases and, accordingly, said generation of thermal energy (q) increases up to an increased thermal energy level, wherein said step of generating further H - ions comprises a step of ionizing said hydrogen which is in contact with said primary material; wherein said step of ionizing said hydrogen is selected from the group comprised of. - a ionization step comprising: - prearranging an electron-donor material that comprises at least one electron-donor chemical element, proximate to said primary material; conveying and impacting said hydrogen on said electron-donor material; - a ionization step comprising a step of continuously or variably or discontinuously supplying an energy vector to said hydrogen, said energy vector selected from the group comprised of: - a ionizing radiation of predetermined nature and frequency; - particle beams, - a ionization step comprising - increasing a temperature of said primary material from a working temperature (T 0) to a predetermined increased temperature (T*), said increased temperature (T*) causing an increase of said H - ions concentration; - maintaining said increased temperature (T*) of said primary material by increasing said removed thermal power until an increased steady-state thermal power (Q 0) is attained. - prearranging a primary material that comprises said transition metal; - bringing and keeping said hydrogen into/in contact with said primary material; - heating said primary material up to an initial temperature (T 1) higher than a predetermined critical temperature; - producing an impulse in said primary material, in order to cause a generation of H- ions starting from said hydrogen, and to cause capture reactions (150,151) of said H - ions by said primary material thus causing a generation of a thermal energy (q); - removing a thermal power deriving from said generated thermal energy (q), while maintaining the temperature of said primary material above said critical temperature, - a ionization step comprising: - prearranging an electron-donor material that comprises at least one electron-donor chemical element, proximate to said primary material; conveying and impacting said hydrogen on said electron-donor material; - prearranging an electron-donor material that comprises at least one electron-donor chemical element, proximate to said primary material; conveying and impacting said hydrogen on said electron-donor material; - a ionization step comprising a step of continuously or variably or discontinuously supplying an energy vector to said hydrogen, said energy vector selected from the group comprised of: - a ionizing radiation of predetermined nature and frequency; - particle beams, - a ionizing radiation of predetermined nature and frequency; - particle beams, - a ionization step comprising - increasing a temperature of said primary material from a working temperature (T 0) to a predetermined increased temperature (T*), said increased temperature (T*) causing an increase of said H - ions concentration; - maintaining said increased temperature (T*) of said primary material by increasing said removed thermal power until an increased steady-state thermal power (Q 0) is attained. - increasing a temperature of said primary material from a working temperature (T 0) to a predetermined increased temperature (T*), said increased temperature (T*) causing an increase of said H - ions concentration; - maintaining said increased temperature (T*) of said primary material by increasing said removed thermal power until an increased steady-state thermal power (Q 0) is attained.