Abstract: An apparatus for the generation of thermal energy comprises a reactor vessel containing a volume of pressurized hydrogen; a hydrogen-storing nickel alloy structure in the reactor vessel and configured to have an electric potential applied across it and to be heated to at least about 100 C; and a heat exchange conduit configured to carry a heat exchange medium past the nickel alloy structure so as to allow thermal energy generated in the nickel alloy structure to be transferred to the heat exchange medium. The hydrogen-storing nickel alloy structure comprises a nickel alloy skeletal catalyst mixed with an oxide. The applied electric potential, and the increase in the gas pressure and temperature of the hydrogen from the applied heat, create a reaction between hydrogen nuclei and nickel nuclei in the nickel alloy structure whereby thermal energy is generated by the emission of phonons from the nickel alloy structure.