TECHNOLOGY FOCUS - INORGANIC CHEMISTRY - Preferred Components: The electron acceptor comprises polycyclic aromatic hydrocarbon and chemical species comprise an electron donor metal ion and solvated electron. The electron donor metal M, polycyclic aromatic hydrocarbon PAH and solvent Solv is comprised in molar ratio of about Mn(PAH)m(Solv)q. The alkali metal comprises lithium and/or potassium. The electron acceptor comprises at least one organo radical and the chemical species comprises at least one organo metal. The electron donor metal, the at least one organo radical and the solvent are comprised in a molar ratio of Mn'(OR)m'.n=0.1-15;m=0.075-7.5;q=1-50;n'=1-6;m'=0.1-10;OR (disclosed)=organo radical such as butyl.Preferred Method: When the hydrogen storage arrangement (S1) in method (M1) has a hydrogen storage arrangement pressure, and the hydrogen has hydrogen pressure, the contacting is performed with hydrogen pressure higher than hydrogen storage arrangement pressure. The hydrogen pressure is comprised in a range of 1-200 (preferably 5-100, especially 10-50) atm. The contacting is performed in single step or is performed in more than one step, where in each step the hydrogen pressure is a hydrogen step pressure and the hydrogen arrangement pressure is a hydrogen storage arrangement step pressure and where hydrogen step pressure and hydrogen storage arrangement step pressure are maintained or increased from one step to another. In method (M1), the contacting is performed at constant temperature. The method (M2) further involves contacting the chemical species with hydrogen to form metal hydride complex within the solvent.    TECHNOLOGY FOCUS - INSTRUMENTATION AND TESTING - Preferred Arrangement: The hydrogen storage arrangement (S1) further comprises hydrogen, where the hydrogen reacts with the chemical species providing metal hydride complex comprised in the solvent.    TECHNOLOGY FOCUS - ORGANIC CHEMISTRY - Preferred Components: The polycyclic aromatic hydrocarbon is polycyclic aromatic hydrocarbon of formula Ca(1-x)AaxHb (I). When the electron donor comprises at least one alkali metal, the polycyclic aromatic hydrocarbon comprises at least one of naphthalene, anthracene, and pyrene and the solvent comprises tetrahydrofuran.A=Si, B and/or N;x=0-1;a and b=stoichiometric coefficients having a ratio b/a of 0-0.8.